* [PATCH] mm: swap: determine swap device by using page nid
@ 2022-04-07 2:09 Yang Shi
2022-04-07 7:52 ` Michal Hocko
2022-04-07 8:13 ` Aaron Lu
0 siblings, 2 replies; 23+ messages in thread
From: Yang Shi @ 2022-04-07 2:09 UTC (permalink / raw)
To: ying.huang, akpm; +Cc: shy828301, linux-mm, linux-kernel
The swap devices are linked to per node priority lists, the swap device
closer to the node has higher priority on that node's priority list.
This is supposed to improve I/O latency, particularly for some fast
devices. But the current code gets nid by calling numa_node_id() which
actually returns the nid that the reclaimer is running on instead of the
nid that the page belongs to.
Pass the page's nid dow to get_swap_pages() in order to pick up the
right swap device. But it doesn't work for the swap slots cache which
is per cpu. We could skip swap slots cache if the current node is not
the page's node, but it may be overkilling. So keep using the current
node's swap slots cache. The issue was found by visual code inspection
so it is not sure how much improvement could be achieved due to lack of
suitable testing device. But anyway the current code does violate the
design.
Cc: Huang Ying <ying.huang@intel.com>
Signed-off-by: Yang Shi <shy828301@gmail.com>
---
include/linux/swap.h | 3 ++-
mm/swap_slots.c | 7 ++++---
mm/swapfile.c | 5 ++---
3 files changed, 8 insertions(+), 7 deletions(-)
diff --git a/include/linux/swap.h b/include/linux/swap.h
index 27093b477c5f..e442cf6b61ea 100644
--- a/include/linux/swap.h
+++ b/include/linux/swap.h
@@ -497,7 +497,8 @@ extern void si_swapinfo(struct sysinfo *);
extern swp_entry_t get_swap_page(struct page *page);
extern void put_swap_page(struct page *page, swp_entry_t entry);
extern swp_entry_t get_swap_page_of_type(int);
-extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size);
+extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size,
+ int node);
extern int add_swap_count_continuation(swp_entry_t, gfp_t);
extern void swap_shmem_alloc(swp_entry_t);
extern int swap_duplicate(swp_entry_t);
diff --git a/mm/swap_slots.c b/mm/swap_slots.c
index 2b5531840583..a1c5cf6a4302 100644
--- a/mm/swap_slots.c
+++ b/mm/swap_slots.c
@@ -264,7 +264,7 @@ static int refill_swap_slots_cache(struct swap_slots_cache *cache)
cache->cur = 0;
if (swap_slot_cache_active)
cache->nr = get_swap_pages(SWAP_SLOTS_CACHE_SIZE,
- cache->slots, 1);
+ cache->slots, 1, numa_node_id());
return cache->nr;
}
@@ -305,12 +305,13 @@ swp_entry_t get_swap_page(struct page *page)
{
swp_entry_t entry;
struct swap_slots_cache *cache;
+ int nid = page_to_nid(page);
entry.val = 0;
if (PageTransHuge(page)) {
if (IS_ENABLED(CONFIG_THP_SWAP))
- get_swap_pages(1, &entry, HPAGE_PMD_NR);
+ get_swap_pages(1, &entry, HPAGE_PMD_NR, nid);
goto out;
}
@@ -342,7 +343,7 @@ swp_entry_t get_swap_page(struct page *page)
goto out;
}
- get_swap_pages(1, &entry, 1);
+ get_swap_pages(1, &entry, 1, nid);
out:
if (mem_cgroup_try_charge_swap(page, entry)) {
put_swap_page(page, entry);
diff --git a/mm/swapfile.c b/mm/swapfile.c
index 63c61f8b2611..151fffe0fd60 100644
--- a/mm/swapfile.c
+++ b/mm/swapfile.c
@@ -1036,13 +1036,13 @@ static void swap_free_cluster(struct swap_info_struct *si, unsigned long idx)
swap_range_free(si, offset, SWAPFILE_CLUSTER);
}
-int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
+int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size,
+ int node)
{
unsigned long size = swap_entry_size(entry_size);
struct swap_info_struct *si, *next;
long avail_pgs;
int n_ret = 0;
- int node;
/* Only single cluster request supported */
WARN_ON_ONCE(n_goal > 1 && size == SWAPFILE_CLUSTER);
@@ -1060,7 +1060,6 @@ int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
atomic_long_sub(n_goal * size, &nr_swap_pages);
start_over:
- node = numa_node_id();
plist_for_each_entry_safe(si, next, &swap_avail_heads[node], avail_lists[node]) {
/* requeue si to after same-priority siblings */
plist_requeue(&si->avail_lists[node], &swap_avail_heads[node]);
--
2.26.3
^ permalink raw reply related [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-07 2:09 [PATCH] mm: swap: determine swap device by using page nid Yang Shi
@ 2022-04-07 7:52 ` Michal Hocko
2022-04-07 17:27 ` Yang Shi
2022-04-07 8:13 ` Aaron Lu
1 sibling, 1 reply; 23+ messages in thread
From: Michal Hocko @ 2022-04-07 7:52 UTC (permalink / raw)
To: Yang Shi; +Cc: ying.huang, akpm, linux-mm, linux-kernel, Aaron Lu
[Cc Aaron who has introduced the per node swap changes]
On Wed 06-04-22 19:09:53, Yang Shi wrote:
> The swap devices are linked to per node priority lists, the swap device
> closer to the node has higher priority on that node's priority list.
> This is supposed to improve I/O latency, particularly for some fast
> devices. But the current code gets nid by calling numa_node_id() which
> actually returns the nid that the reclaimer is running on instead of the
> nid that the page belongs to.
>
> Pass the page's nid dow to get_swap_pages() in order to pick up the
> right swap device. But it doesn't work for the swap slots cache which
> is per cpu. We could skip swap slots cache if the current node is not
> the page's node, but it may be overkilling. So keep using the current
> node's swap slots cache. The issue was found by visual code inspection
> so it is not sure how much improvement could be achieved due to lack of
> suitable testing device. But anyway the current code does violate the
> design.
Do you have any perf numbers for this change?
> Cc: Huang Ying <ying.huang@intel.com>
> Signed-off-by: Yang Shi <shy828301@gmail.com>
> ---
> include/linux/swap.h | 3 ++-
> mm/swap_slots.c | 7 ++++---
> mm/swapfile.c | 5 ++---
> 3 files changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/include/linux/swap.h b/include/linux/swap.h
> index 27093b477c5f..e442cf6b61ea 100644
> --- a/include/linux/swap.h
> +++ b/include/linux/swap.h
> @@ -497,7 +497,8 @@ extern void si_swapinfo(struct sysinfo *);
> extern swp_entry_t get_swap_page(struct page *page);
> extern void put_swap_page(struct page *page, swp_entry_t entry);
> extern swp_entry_t get_swap_page_of_type(int);
> -extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size);
> +extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size,
> + int node);
> extern int add_swap_count_continuation(swp_entry_t, gfp_t);
> extern void swap_shmem_alloc(swp_entry_t);
> extern int swap_duplicate(swp_entry_t);
> diff --git a/mm/swap_slots.c b/mm/swap_slots.c
> index 2b5531840583..a1c5cf6a4302 100644
> --- a/mm/swap_slots.c
> +++ b/mm/swap_slots.c
> @@ -264,7 +264,7 @@ static int refill_swap_slots_cache(struct swap_slots_cache *cache)
> cache->cur = 0;
> if (swap_slot_cache_active)
> cache->nr = get_swap_pages(SWAP_SLOTS_CACHE_SIZE,
> - cache->slots, 1);
> + cache->slots, 1, numa_node_id());
>
> return cache->nr;
> }
> @@ -305,12 +305,13 @@ swp_entry_t get_swap_page(struct page *page)
> {
> swp_entry_t entry;
> struct swap_slots_cache *cache;
> + int nid = page_to_nid(page);
>
> entry.val = 0;
>
> if (PageTransHuge(page)) {
> if (IS_ENABLED(CONFIG_THP_SWAP))
> - get_swap_pages(1, &entry, HPAGE_PMD_NR);
> + get_swap_pages(1, &entry, HPAGE_PMD_NR, nid);
> goto out;
> }
>
> @@ -342,7 +343,7 @@ swp_entry_t get_swap_page(struct page *page)
> goto out;
> }
>
> - get_swap_pages(1, &entry, 1);
> + get_swap_pages(1, &entry, 1, nid);
> out:
> if (mem_cgroup_try_charge_swap(page, entry)) {
> put_swap_page(page, entry);
> diff --git a/mm/swapfile.c b/mm/swapfile.c
> index 63c61f8b2611..151fffe0fd60 100644
> --- a/mm/swapfile.c
> +++ b/mm/swapfile.c
> @@ -1036,13 +1036,13 @@ static void swap_free_cluster(struct swap_info_struct *si, unsigned long idx)
> swap_range_free(si, offset, SWAPFILE_CLUSTER);
> }
>
> -int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
> +int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size,
> + int node)
> {
> unsigned long size = swap_entry_size(entry_size);
> struct swap_info_struct *si, *next;
> long avail_pgs;
> int n_ret = 0;
> - int node;
>
> /* Only single cluster request supported */
> WARN_ON_ONCE(n_goal > 1 && size == SWAPFILE_CLUSTER);
> @@ -1060,7 +1060,6 @@ int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
> atomic_long_sub(n_goal * size, &nr_swap_pages);
>
> start_over:
> - node = numa_node_id();
> plist_for_each_entry_safe(si, next, &swap_avail_heads[node], avail_lists[node]) {
> /* requeue si to after same-priority siblings */
> plist_requeue(&si->avail_lists[node], &swap_avail_heads[node]);
> --
> 2.26.3
--
Michal Hocko
SUSE Labs
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-07 2:09 [PATCH] mm: swap: determine swap device by using page nid Yang Shi
2022-04-07 7:52 ` Michal Hocko
@ 2022-04-07 8:13 ` Aaron Lu
2022-04-07 17:36 ` Yang Shi
1 sibling, 1 reply; 23+ messages in thread
From: Aaron Lu @ 2022-04-07 8:13 UTC (permalink / raw)
To: Yang Shi; +Cc: ying.huang, akpm, linux-mm, linux-kernel
On Wed, Apr 06, 2022 at 07:09:53PM -0700, Yang Shi wrote:
> The swap devices are linked to per node priority lists, the swap device
> closer to the node has higher priority on that node's priority list.
> This is supposed to improve I/O latency, particularly for some fast
> devices. But the current code gets nid by calling numa_node_id() which
> actually returns the nid that the reclaimer is running on instead of the
> nid that the page belongs to.
>
Right.
> Pass the page's nid dow to get_swap_pages() in order to pick up the
> right swap device. But it doesn't work for the swap slots cache which
> is per cpu. We could skip swap slots cache if the current node is not
> the page's node, but it may be overkilling. So keep using the current
> node's swap slots cache. The issue was found by visual code inspection
> so it is not sure how much improvement could be achieved due to lack of
> suitable testing device. But anyway the current code does violate the
> design.
>
I intentionally used the reclaimer's nid because I think when swapping
out to a device, it is faster when the device is on the same node as
the cpu.
Anyway, I think I can make a test case where the workload allocates all
its memory on the remote node and its workingset memory is larger then
the available memory so swap is triggered, then we can see which way
achieves better performance. Sounds reasonable to you?
> Cc: Huang Ying <ying.huang@intel.com>
> Signed-off-by: Yang Shi <shy828301@gmail.com>
> ---
> include/linux/swap.h | 3 ++-
> mm/swap_slots.c | 7 ++++---
> mm/swapfile.c | 5 ++---
> 3 files changed, 8 insertions(+), 7 deletions(-)
>
> diff --git a/include/linux/swap.h b/include/linux/swap.h
> index 27093b477c5f..e442cf6b61ea 100644
> --- a/include/linux/swap.h
> +++ b/include/linux/swap.h
> @@ -497,7 +497,8 @@ extern void si_swapinfo(struct sysinfo *);
> extern swp_entry_t get_swap_page(struct page *page);
> extern void put_swap_page(struct page *page, swp_entry_t entry);
> extern swp_entry_t get_swap_page_of_type(int);
> -extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size);
> +extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size,
> + int node);
> extern int add_swap_count_continuation(swp_entry_t, gfp_t);
> extern void swap_shmem_alloc(swp_entry_t);
> extern int swap_duplicate(swp_entry_t);
> diff --git a/mm/swap_slots.c b/mm/swap_slots.c
> index 2b5531840583..a1c5cf6a4302 100644
> --- a/mm/swap_slots.c
> +++ b/mm/swap_slots.c
> @@ -264,7 +264,7 @@ static int refill_swap_slots_cache(struct swap_slots_cache *cache)
> cache->cur = 0;
> if (swap_slot_cache_active)
> cache->nr = get_swap_pages(SWAP_SLOTS_CACHE_SIZE,
> - cache->slots, 1);
> + cache->slots, 1, numa_node_id());
>
> return cache->nr;
> }
> @@ -305,12 +305,13 @@ swp_entry_t get_swap_page(struct page *page)
> {
> swp_entry_t entry;
> struct swap_slots_cache *cache;
> + int nid = page_to_nid(page);
>
> entry.val = 0;
>
> if (PageTransHuge(page)) {
> if (IS_ENABLED(CONFIG_THP_SWAP))
> - get_swap_pages(1, &entry, HPAGE_PMD_NR);
> + get_swap_pages(1, &entry, HPAGE_PMD_NR, nid);
> goto out;
> }
>
> @@ -342,7 +343,7 @@ swp_entry_t get_swap_page(struct page *page)
> goto out;
> }
>
> - get_swap_pages(1, &entry, 1);
> + get_swap_pages(1, &entry, 1, nid);
> out:
> if (mem_cgroup_try_charge_swap(page, entry)) {
> put_swap_page(page, entry);
> diff --git a/mm/swapfile.c b/mm/swapfile.c
> index 63c61f8b2611..151fffe0fd60 100644
> --- a/mm/swapfile.c
> +++ b/mm/swapfile.c
> @@ -1036,13 +1036,13 @@ static void swap_free_cluster(struct swap_info_struct *si, unsigned long idx)
> swap_range_free(si, offset, SWAPFILE_CLUSTER);
> }
>
> -int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
> +int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size,
> + int node)
> {
> unsigned long size = swap_entry_size(entry_size);
> struct swap_info_struct *si, *next;
> long avail_pgs;
> int n_ret = 0;
> - int node;
>
> /* Only single cluster request supported */
> WARN_ON_ONCE(n_goal > 1 && size == SWAPFILE_CLUSTER);
> @@ -1060,7 +1060,6 @@ int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
> atomic_long_sub(n_goal * size, &nr_swap_pages);
>
> start_over:
> - node = numa_node_id();
> plist_for_each_entry_safe(si, next, &swap_avail_heads[node], avail_lists[node]) {
> /* requeue si to after same-priority siblings */
> plist_requeue(&si->avail_lists[node], &swap_avail_heads[node]);
> --
> 2.26.3
>
>
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-07 7:52 ` Michal Hocko
@ 2022-04-07 17:27 ` Yang Shi
0 siblings, 0 replies; 23+ messages in thread
From: Yang Shi @ 2022-04-07 17:27 UTC (permalink / raw)
To: Michal Hocko
Cc: Huang Ying, Andrew Morton, Linux MM, Linux Kernel Mailing List, Aaron Lu
On Thu, Apr 7, 2022 at 12:52 AM Michal Hocko <mhocko@suse.com> wrote:
>
> [Cc Aaron who has introduced the per node swap changes]
>
> On Wed 06-04-22 19:09:53, Yang Shi wrote:
> > The swap devices are linked to per node priority lists, the swap device
> > closer to the node has higher priority on that node's priority list.
> > This is supposed to improve I/O latency, particularly for some fast
> > devices. But the current code gets nid by calling numa_node_id() which
> > actually returns the nid that the reclaimer is running on instead of the
> > nid that the page belongs to.
> >
> > Pass the page's nid dow to get_swap_pages() in order to pick up the
> > right swap device. But it doesn't work for the swap slots cache which
> > is per cpu. We could skip swap slots cache if the current node is not
> > the page's node, but it may be overkilling. So keep using the current
> > node's swap slots cache. The issue was found by visual code inspection
> > so it is not sure how much improvement could be achieved due to lack of
> > suitable testing device. But anyway the current code does violate the
> > design.
>
> Do you have any perf numbers for this change?
No, it was found by visual code inspection and offline discussion with
Huang Ying.
>
> > Cc: Huang Ying <ying.huang@intel.com>
> > Signed-off-by: Yang Shi <shy828301@gmail.com>
> > ---
> > include/linux/swap.h | 3 ++-
> > mm/swap_slots.c | 7 ++++---
> > mm/swapfile.c | 5 ++---
> > 3 files changed, 8 insertions(+), 7 deletions(-)
> >
> > diff --git a/include/linux/swap.h b/include/linux/swap.h
> > index 27093b477c5f..e442cf6b61ea 100644
> > --- a/include/linux/swap.h
> > +++ b/include/linux/swap.h
> > @@ -497,7 +497,8 @@ extern void si_swapinfo(struct sysinfo *);
> > extern swp_entry_t get_swap_page(struct page *page);
> > extern void put_swap_page(struct page *page, swp_entry_t entry);
> > extern swp_entry_t get_swap_page_of_type(int);
> > -extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size);
> > +extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size,
> > + int node);
> > extern int add_swap_count_continuation(swp_entry_t, gfp_t);
> > extern void swap_shmem_alloc(swp_entry_t);
> > extern int swap_duplicate(swp_entry_t);
> > diff --git a/mm/swap_slots.c b/mm/swap_slots.c
> > index 2b5531840583..a1c5cf6a4302 100644
> > --- a/mm/swap_slots.c
> > +++ b/mm/swap_slots.c
> > @@ -264,7 +264,7 @@ static int refill_swap_slots_cache(struct swap_slots_cache *cache)
> > cache->cur = 0;
> > if (swap_slot_cache_active)
> > cache->nr = get_swap_pages(SWAP_SLOTS_CACHE_SIZE,
> > - cache->slots, 1);
> > + cache->slots, 1, numa_node_id());
> >
> > return cache->nr;
> > }
> > @@ -305,12 +305,13 @@ swp_entry_t get_swap_page(struct page *page)
> > {
> > swp_entry_t entry;
> > struct swap_slots_cache *cache;
> > + int nid = page_to_nid(page);
> >
> > entry.val = 0;
> >
> > if (PageTransHuge(page)) {
> > if (IS_ENABLED(CONFIG_THP_SWAP))
> > - get_swap_pages(1, &entry, HPAGE_PMD_NR);
> > + get_swap_pages(1, &entry, HPAGE_PMD_NR, nid);
> > goto out;
> > }
> >
> > @@ -342,7 +343,7 @@ swp_entry_t get_swap_page(struct page *page)
> > goto out;
> > }
> >
> > - get_swap_pages(1, &entry, 1);
> > + get_swap_pages(1, &entry, 1, nid);
> > out:
> > if (mem_cgroup_try_charge_swap(page, entry)) {
> > put_swap_page(page, entry);
> > diff --git a/mm/swapfile.c b/mm/swapfile.c
> > index 63c61f8b2611..151fffe0fd60 100644
> > --- a/mm/swapfile.c
> > +++ b/mm/swapfile.c
> > @@ -1036,13 +1036,13 @@ static void swap_free_cluster(struct swap_info_struct *si, unsigned long idx)
> > swap_range_free(si, offset, SWAPFILE_CLUSTER);
> > }
> >
> > -int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
> > +int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size,
> > + int node)
> > {
> > unsigned long size = swap_entry_size(entry_size);
> > struct swap_info_struct *si, *next;
> > long avail_pgs;
> > int n_ret = 0;
> > - int node;
> >
> > /* Only single cluster request supported */
> > WARN_ON_ONCE(n_goal > 1 && size == SWAPFILE_CLUSTER);
> > @@ -1060,7 +1060,6 @@ int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
> > atomic_long_sub(n_goal * size, &nr_swap_pages);
> >
> > start_over:
> > - node = numa_node_id();
> > plist_for_each_entry_safe(si, next, &swap_avail_heads[node], avail_lists[node]) {
> > /* requeue si to after same-priority siblings */
> > plist_requeue(&si->avail_lists[node], &swap_avail_heads[node]);
> > --
> > 2.26.3
>
> --
> Michal Hocko
> SUSE Labs
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-07 8:13 ` Aaron Lu
@ 2022-04-07 17:36 ` Yang Shi
2022-04-20 8:33 ` Aaron Lu
0 siblings, 1 reply; 23+ messages in thread
From: Yang Shi @ 2022-04-07 17:36 UTC (permalink / raw)
To: Aaron Lu; +Cc: Huang Ying, Andrew Morton, Linux MM, Linux Kernel Mailing List
On Thu, Apr 7, 2022 at 1:12 AM Aaron Lu <aaron.lu@intel.com> wrote:
>
> On Wed, Apr 06, 2022 at 07:09:53PM -0700, Yang Shi wrote:
> > The swap devices are linked to per node priority lists, the swap device
> > closer to the node has higher priority on that node's priority list.
> > This is supposed to improve I/O latency, particularly for some fast
> > devices. But the current code gets nid by calling numa_node_id() which
> > actually returns the nid that the reclaimer is running on instead of the
> > nid that the page belongs to.
> >
>
> Right.
>
> > Pass the page's nid dow to get_swap_pages() in order to pick up the
> > right swap device. But it doesn't work for the swap slots cache which
> > is per cpu. We could skip swap slots cache if the current node is not
> > the page's node, but it may be overkilling. So keep using the current
> > node's swap slots cache. The issue was found by visual code inspection
> > so it is not sure how much improvement could be achieved due to lack of
> > suitable testing device. But anyway the current code does violate the
> > design.
> >
>
> I intentionally used the reclaimer's nid because I think when swapping
> out to a device, it is faster when the device is on the same node as
> the cpu.
OK, the offline discussion with Huang Ying showed the design was to
have page's nid in order to achieve better I/O performance (more
noticeable on faster devices) since the reclaimer may be running on a
different node from the reclaimed page.
>
> Anyway, I think I can make a test case where the workload allocates all
> its memory on the remote node and its workingset memory is larger then
> the available memory so swap is triggered, then we can see which way
> achieves better performance. Sounds reasonable to you?
Yeah, definitely, thank you so much. I don't have a fast enough device
by hand to show the difference right now. If you could get some data
it would be perfect.
BTW, this patch doesn't change the node for swap slots cache, so it
may still use the swap device on a remote node if swap slots cache is
used.
>
> > Cc: Huang Ying <ying.huang@intel.com>
> > Signed-off-by: Yang Shi <shy828301@gmail.com>
> > ---
> > include/linux/swap.h | 3 ++-
> > mm/swap_slots.c | 7 ++++---
> > mm/swapfile.c | 5 ++---
> > 3 files changed, 8 insertions(+), 7 deletions(-)
> >
> > diff --git a/include/linux/swap.h b/include/linux/swap.h
> > index 27093b477c5f..e442cf6b61ea 100644
> > --- a/include/linux/swap.h
> > +++ b/include/linux/swap.h
> > @@ -497,7 +497,8 @@ extern void si_swapinfo(struct sysinfo *);
> > extern swp_entry_t get_swap_page(struct page *page);
> > extern void put_swap_page(struct page *page, swp_entry_t entry);
> > extern swp_entry_t get_swap_page_of_type(int);
> > -extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size);
> > +extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size,
> > + int node);
> > extern int add_swap_count_continuation(swp_entry_t, gfp_t);
> > extern void swap_shmem_alloc(swp_entry_t);
> > extern int swap_duplicate(swp_entry_t);
> > diff --git a/mm/swap_slots.c b/mm/swap_slots.c
> > index 2b5531840583..a1c5cf6a4302 100644
> > --- a/mm/swap_slots.c
> > +++ b/mm/swap_slots.c
> > @@ -264,7 +264,7 @@ static int refill_swap_slots_cache(struct swap_slots_cache *cache)
> > cache->cur = 0;
> > if (swap_slot_cache_active)
> > cache->nr = get_swap_pages(SWAP_SLOTS_CACHE_SIZE,
> > - cache->slots, 1);
> > + cache->slots, 1, numa_node_id());
> >
> > return cache->nr;
> > }
> > @@ -305,12 +305,13 @@ swp_entry_t get_swap_page(struct page *page)
> > {
> > swp_entry_t entry;
> > struct swap_slots_cache *cache;
> > + int nid = page_to_nid(page);
> >
> > entry.val = 0;
> >
> > if (PageTransHuge(page)) {
> > if (IS_ENABLED(CONFIG_THP_SWAP))
> > - get_swap_pages(1, &entry, HPAGE_PMD_NR);
> > + get_swap_pages(1, &entry, HPAGE_PMD_NR, nid);
> > goto out;
> > }
> >
> > @@ -342,7 +343,7 @@ swp_entry_t get_swap_page(struct page *page)
> > goto out;
> > }
> >
> > - get_swap_pages(1, &entry, 1);
> > + get_swap_pages(1, &entry, 1, nid);
> > out:
> > if (mem_cgroup_try_charge_swap(page, entry)) {
> > put_swap_page(page, entry);
> > diff --git a/mm/swapfile.c b/mm/swapfile.c
> > index 63c61f8b2611..151fffe0fd60 100644
> > --- a/mm/swapfile.c
> > +++ b/mm/swapfile.c
> > @@ -1036,13 +1036,13 @@ static void swap_free_cluster(struct swap_info_struct *si, unsigned long idx)
> > swap_range_free(si, offset, SWAPFILE_CLUSTER);
> > }
> >
> > -int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
> > +int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size,
> > + int node)
> > {
> > unsigned long size = swap_entry_size(entry_size);
> > struct swap_info_struct *si, *next;
> > long avail_pgs;
> > int n_ret = 0;
> > - int node;
> >
> > /* Only single cluster request supported */
> > WARN_ON_ONCE(n_goal > 1 && size == SWAPFILE_CLUSTER);
> > @@ -1060,7 +1060,6 @@ int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
> > atomic_long_sub(n_goal * size, &nr_swap_pages);
> >
> > start_over:
> > - node = numa_node_id();
> > plist_for_each_entry_safe(si, next, &swap_avail_heads[node], avail_lists[node]) {
> > /* requeue si to after same-priority siblings */
> > plist_requeue(&si->avail_lists[node], &swap_avail_heads[node]);
> > --
> > 2.26.3
> >
> >
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-07 17:36 ` Yang Shi
@ 2022-04-20 8:33 ` Aaron Lu
2022-04-20 22:21 ` Yang Shi
2022-04-21 7:49 ` ying.huang
0 siblings, 2 replies; 23+ messages in thread
From: Aaron Lu @ 2022-04-20 8:33 UTC (permalink / raw)
To: Yang Shi
Cc: Huang Ying, Michal Hocko, Andrew Morton, Linux MM,
Linux Kernel Mailing List
On Thu, Apr 07, 2022 at 10:36:54AM -0700, Yang Shi wrote:
> On Thu, Apr 7, 2022 at 1:12 AM Aaron Lu <aaron.lu@intel.com> wrote:
> >
> > On Wed, Apr 06, 2022 at 07:09:53PM -0700, Yang Shi wrote:
> > > The swap devices are linked to per node priority lists, the swap device
> > > closer to the node has higher priority on that node's priority list.
> > > This is supposed to improve I/O latency, particularly for some fast
> > > devices. But the current code gets nid by calling numa_node_id() which
> > > actually returns the nid that the reclaimer is running on instead of the
> > > nid that the page belongs to.
> > >
> >
> > Right.
> >
> > > Pass the page's nid dow to get_swap_pages() in order to pick up the
> > > right swap device. But it doesn't work for the swap slots cache which
> > > is per cpu. We could skip swap slots cache if the current node is not
> > > the page's node, but it may be overkilling. So keep using the current
> > > node's swap slots cache. The issue was found by visual code inspection
> > > so it is not sure how much improvement could be achieved due to lack of
> > > suitable testing device. But anyway the current code does violate the
> > > design.
> > >
> >
> > I intentionally used the reclaimer's nid because I think when swapping
> > out to a device, it is faster when the device is on the same node as
> > the cpu.
>
> OK, the offline discussion with Huang Ying showed the design was to
> have page's nid in order to achieve better I/O performance (more
> noticeable on faster devices) since the reclaimer may be running on a
> different node from the reclaimed page.
>
> >
> > Anyway, I think I can make a test case where the workload allocates all
> > its memory on the remote node and its workingset memory is larger then
> > the available memory so swap is triggered, then we can see which way
> > achieves better performance. Sounds reasonable to you?
>
> Yeah, definitely, thank you so much. I don't have a fast enough device
> by hand to show the difference right now. If you could get some data
> it would be perfect.
>
Failed to find a test box that has two NVMe disks attached to different
nodes and since Shanghai is locked down right now, we couldn't install
another NVMe on the box so I figured it might be OK to test on a box that
has a single NVMe attached to node 0 like this:
1) restrict the test processes to run on node 0 and allocate on node 1;
2) restrict the test processes to run on node 1 and allocate on node 0.
In case 1), the reclaimer's node id is the same as the swap device's so
it's the same as current behaviour and in case 2), the page's node id is
the same as the swap device's so it's what your patch proposed.
The test I used is vm-scalability/case-swap-w-rand:
https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/tree/case-swap-w-seq
which spawns $nr_task processes and each will mmap $size and then
randomly write to that area. I set nr_task=32 and $size=4G, so a total
of 128G memory will be needed and I used memory.limit_in_bytes to
restrict the available memory to 64G, to make sure swap is triggered.
The reason why cgroup is used is to avoid waking up the per-node kswapd
which can trigger swapping with reclaimer/page/swap device all having the
same node id.
And I don't see a measuable difference from the result:
case1(using reclaimer's node id) vm-scalability.throughput: 10574 KB/s
case2(using page's node id) vm-scalability.throughput: 10567 KB/s
My interpretation of the result is, when reclaiming a remote page, it
doesn't matter much which swap device to use if the swap device is a IO
device.
Later Ying reminded me we have test box that has optane installed on
different nodes so I also tested there: Icelake 2 sockets server with 2
optane installed on each node. I did the test there like this:
1) restrict the test processes to run on node 0 and allocate on node 1
and only swapon pmem0, which is the optane backed swap device on node 0;
2) restrict the test processes to run on node 0 and allocate on node 1
and only swapon pmem1, which is the optane backed swap device on node 1.
So case 1) is current behaviour and case 2) is what your patch proposed.
With the same test and the same nr_task/size, the result is:
case1(using reclaimer's node id) vm-scalability.throughput: 71033 KB/s
case2(using page's node id) vm-scalability.throughput: 58753 KB/s
The result suggested when using a memory like device as swap device,
it's better to use the reclaimer's node id when swapping.
What do you think of these tests and results?
Thanks,
Aaron
> BTW, this patch doesn't change the node for swap slots cache, so it
> may still use the swap device on a remote node if swap slots cache is
> used.
>
> >
> > > Cc: Huang Ying <ying.huang@intel.com>
> > > Signed-off-by: Yang Shi <shy828301@gmail.com>
> > > ---
> > > include/linux/swap.h | 3 ++-
> > > mm/swap_slots.c | 7 ++++---
> > > mm/swapfile.c | 5 ++---
> > > 3 files changed, 8 insertions(+), 7 deletions(-)
> > >
> > > diff --git a/include/linux/swap.h b/include/linux/swap.h
> > > index 27093b477c5f..e442cf6b61ea 100644
> > > --- a/include/linux/swap.h
> > > +++ b/include/linux/swap.h
> > > @@ -497,7 +497,8 @@ extern void si_swapinfo(struct sysinfo *);
> > > extern swp_entry_t get_swap_page(struct page *page);
> > > extern void put_swap_page(struct page *page, swp_entry_t entry);
> > > extern swp_entry_t get_swap_page_of_type(int);
> > > -extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size);
> > > +extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size,
> > > + int node);
> > > extern int add_swap_count_continuation(swp_entry_t, gfp_t);
> > > extern void swap_shmem_alloc(swp_entry_t);
> > > extern int swap_duplicate(swp_entry_t);
> > > diff --git a/mm/swap_slots.c b/mm/swap_slots.c
> > > index 2b5531840583..a1c5cf6a4302 100644
> > > --- a/mm/swap_slots.c
> > > +++ b/mm/swap_slots.c
> > > @@ -264,7 +264,7 @@ static int refill_swap_slots_cache(struct swap_slots_cache *cache)
> > > cache->cur = 0;
> > > if (swap_slot_cache_active)
> > > cache->nr = get_swap_pages(SWAP_SLOTS_CACHE_SIZE,
> > > - cache->slots, 1);
> > > + cache->slots, 1, numa_node_id());
> > >
> > > return cache->nr;
> > > }
> > > @@ -305,12 +305,13 @@ swp_entry_t get_swap_page(struct page *page)
> > > {
> > > swp_entry_t entry;
> > > struct swap_slots_cache *cache;
> > > + int nid = page_to_nid(page);
> > >
> > > entry.val = 0;
> > >
> > > if (PageTransHuge(page)) {
> > > if (IS_ENABLED(CONFIG_THP_SWAP))
> > > - get_swap_pages(1, &entry, HPAGE_PMD_NR);
> > > + get_swap_pages(1, &entry, HPAGE_PMD_NR, nid);
> > > goto out;
> > > }
> > >
> > > @@ -342,7 +343,7 @@ swp_entry_t get_swap_page(struct page *page)
> > > goto out;
> > > }
> > >
> > > - get_swap_pages(1, &entry, 1);
> > > + get_swap_pages(1, &entry, 1, nid);
> > > out:
> > > if (mem_cgroup_try_charge_swap(page, entry)) {
> > > put_swap_page(page, entry);
> > > diff --git a/mm/swapfile.c b/mm/swapfile.c
> > > index 63c61f8b2611..151fffe0fd60 100644
> > > --- a/mm/swapfile.c
> > > +++ b/mm/swapfile.c
> > > @@ -1036,13 +1036,13 @@ static void swap_free_cluster(struct swap_info_struct *si, unsigned long idx)
> > > swap_range_free(si, offset, SWAPFILE_CLUSTER);
> > > }
> > >
> > > -int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
> > > +int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size,
> > > + int node)
> > > {
> > > unsigned long size = swap_entry_size(entry_size);
> > > struct swap_info_struct *si, *next;
> > > long avail_pgs;
> > > int n_ret = 0;
> > > - int node;
> > >
> > > /* Only single cluster request supported */
> > > WARN_ON_ONCE(n_goal > 1 && size == SWAPFILE_CLUSTER);
> > > @@ -1060,7 +1060,6 @@ int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
> > > atomic_long_sub(n_goal * size, &nr_swap_pages);
> > >
> > > start_over:
> > > - node = numa_node_id();
> > > plist_for_each_entry_safe(si, next, &swap_avail_heads[node], avail_lists[node]) {
> > > /* requeue si to after same-priority siblings */
> > > plist_requeue(&si->avail_lists[node], &swap_avail_heads[node]);
> > > --
> > > 2.26.3
> > >
> > >
>
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-20 8:33 ` Aaron Lu
@ 2022-04-20 22:21 ` Yang Shi
2022-04-21 7:34 ` Aaron Lu
2022-04-21 7:49 ` ying.huang
1 sibling, 1 reply; 23+ messages in thread
From: Yang Shi @ 2022-04-20 22:21 UTC (permalink / raw)
To: Aaron Lu
Cc: Huang Ying, Michal Hocko, Andrew Morton, Linux MM,
Linux Kernel Mailing List
On Wed, Apr 20, 2022 at 1:33 AM Aaron Lu <aaron.lu@intel.com> wrote:
>
> On Thu, Apr 07, 2022 at 10:36:54AM -0700, Yang Shi wrote:
> > On Thu, Apr 7, 2022 at 1:12 AM Aaron Lu <aaron.lu@intel.com> wrote:
> > >
> > > On Wed, Apr 06, 2022 at 07:09:53PM -0700, Yang Shi wrote:
> > > > The swap devices are linked to per node priority lists, the swap device
> > > > closer to the node has higher priority on that node's priority list.
> > > > This is supposed to improve I/O latency, particularly for some fast
> > > > devices. But the current code gets nid by calling numa_node_id() which
> > > > actually returns the nid that the reclaimer is running on instead of the
> > > > nid that the page belongs to.
> > > >
> > >
> > > Right.
> > >
> > > > Pass the page's nid dow to get_swap_pages() in order to pick up the
> > > > right swap device. But it doesn't work for the swap slots cache which
> > > > is per cpu. We could skip swap slots cache if the current node is not
> > > > the page's node, but it may be overkilling. So keep using the current
> > > > node's swap slots cache. The issue was found by visual code inspection
> > > > so it is not sure how much improvement could be achieved due to lack of
> > > > suitable testing device. But anyway the current code does violate the
> > > > design.
> > > >
> > >
> > > I intentionally used the reclaimer's nid because I think when swapping
> > > out to a device, it is faster when the device is on the same node as
> > > the cpu.
> >
> > OK, the offline discussion with Huang Ying showed the design was to
> > have page's nid in order to achieve better I/O performance (more
> > noticeable on faster devices) since the reclaimer may be running on a
> > different node from the reclaimed page.
> >
> > >
> > > Anyway, I think I can make a test case where the workload allocates all
> > > its memory on the remote node and its workingset memory is larger then
> > > the available memory so swap is triggered, then we can see which way
> > > achieves better performance. Sounds reasonable to you?
> >
> > Yeah, definitely, thank you so much. I don't have a fast enough device
> > by hand to show the difference right now. If you could get some data
> > it would be perfect.
> >
>
> Failed to find a test box that has two NVMe disks attached to different
> nodes and since Shanghai is locked down right now, we couldn't install
> another NVMe on the box so I figured it might be OK to test on a box that
> has a single NVMe attached to node 0 like this:
>
> 1) restrict the test processes to run on node 0 and allocate on node 1;
> 2) restrict the test processes to run on node 1 and allocate on node 0.
>
> In case 1), the reclaimer's node id is the same as the swap device's so
> it's the same as current behaviour and in case 2), the page's node id is
> the same as the swap device's so it's what your patch proposed.
>
> The test I used is vm-scalability/case-swap-w-rand:
> https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/tree/case-swap-w-seq
> which spawns $nr_task processes and each will mmap $size and then
> randomly write to that area. I set nr_task=32 and $size=4G, so a total
> of 128G memory will be needed and I used memory.limit_in_bytes to
> restrict the available memory to 64G, to make sure swap is triggered.
>
> The reason why cgroup is used is to avoid waking up the per-node kswapd
> which can trigger swapping with reclaimer/page/swap device all having the
> same node id.
>
> And I don't see a measuable difference from the result:
> case1(using reclaimer's node id) vm-scalability.throughput: 10574 KB/s
> case2(using page's node id) vm-scalability.throughput: 10567 KB/s
>
> My interpretation of the result is, when reclaiming a remote page, it
> doesn't matter much which swap device to use if the swap device is a IO
> device.
>
> Later Ying reminded me we have test box that has optane installed on
> different nodes so I also tested there: Icelake 2 sockets server with 2
> optane installed on each node. I did the test there like this:
> 1) restrict the test processes to run on node 0 and allocate on node 1
> and only swapon pmem0, which is the optane backed swap device on node 0;
> 2) restrict the test processes to run on node 0 and allocate on node 1
> and only swapon pmem1, which is the optane backed swap device on node 1.
>
> So case 1) is current behaviour and case 2) is what your patch proposed.
>
> With the same test and the same nr_task/size, the result is:
> case1(using reclaimer's node id) vm-scalability.throughput: 71033 KB/s
> case2(using page's node id) vm-scalability.throughput: 58753 KB/s
>
> The result suggested when using a memory like device as swap device,
> it's better to use the reclaimer's node id when swapping.
>
> What do you think of these tests and results?
Thanks, Aaron. Since you are using PMEM so I'm supposed case #2
actually has 1 more cross node memory copy than case #1. Swapping
doesn't incur the block I/O (DMA) but memory copy in this
configuration.
IIUC, case #1 would do node1 -> node0 -> pmem0, but case #2 would do
node1 -> node0 -> pmem1.
Actually I was thinking about Optane SSD instead of PMEM when
discussing this with Ying offline. Not sure if Optane SSD would have
any measurable difference or not. But anyway if PMEM is used as swap
device the current implementation does make more sense.
>
> Thanks,
> Aaron
>
> > BTW, this patch doesn't change the node for swap slots cache, so it
> > may still use the swap device on a remote node if swap slots cache is
> > used.
> >
> > >
> > > > Cc: Huang Ying <ying.huang@intel.com>
> > > > Signed-off-by: Yang Shi <shy828301@gmail.com>
> > > > ---
> > > > include/linux/swap.h | 3 ++-
> > > > mm/swap_slots.c | 7 ++++---
> > > > mm/swapfile.c | 5 ++---
> > > > 3 files changed, 8 insertions(+), 7 deletions(-)
> > > >
> > > > diff --git a/include/linux/swap.h b/include/linux/swap.h
> > > > index 27093b477c5f..e442cf6b61ea 100644
> > > > --- a/include/linux/swap.h
> > > > +++ b/include/linux/swap.h
> > > > @@ -497,7 +497,8 @@ extern void si_swapinfo(struct sysinfo *);
> > > > extern swp_entry_t get_swap_page(struct page *page);
> > > > extern void put_swap_page(struct page *page, swp_entry_t entry);
> > > > extern swp_entry_t get_swap_page_of_type(int);
> > > > -extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size);
> > > > +extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size,
> > > > + int node);
> > > > extern int add_swap_count_continuation(swp_entry_t, gfp_t);
> > > > extern void swap_shmem_alloc(swp_entry_t);
> > > > extern int swap_duplicate(swp_entry_t);
> > > > diff --git a/mm/swap_slots.c b/mm/swap_slots.c
> > > > index 2b5531840583..a1c5cf6a4302 100644
> > > > --- a/mm/swap_slots.c
> > > > +++ b/mm/swap_slots.c
> > > > @@ -264,7 +264,7 @@ static int refill_swap_slots_cache(struct swap_slots_cache *cache)
> > > > cache->cur = 0;
> > > > if (swap_slot_cache_active)
> > > > cache->nr = get_swap_pages(SWAP_SLOTS_CACHE_SIZE,
> > > > - cache->slots, 1);
> > > > + cache->slots, 1, numa_node_id());
> > > >
> > > > return cache->nr;
> > > > }
> > > > @@ -305,12 +305,13 @@ swp_entry_t get_swap_page(struct page *page)
> > > > {
> > > > swp_entry_t entry;
> > > > struct swap_slots_cache *cache;
> > > > + int nid = page_to_nid(page);
> > > >
> > > > entry.val = 0;
> > > >
> > > > if (PageTransHuge(page)) {
> > > > if (IS_ENABLED(CONFIG_THP_SWAP))
> > > > - get_swap_pages(1, &entry, HPAGE_PMD_NR);
> > > > + get_swap_pages(1, &entry, HPAGE_PMD_NR, nid);
> > > > goto out;
> > > > }
> > > >
> > > > @@ -342,7 +343,7 @@ swp_entry_t get_swap_page(struct page *page)
> > > > goto out;
> > > > }
> > > >
> > > > - get_swap_pages(1, &entry, 1);
> > > > + get_swap_pages(1, &entry, 1, nid);
> > > > out:
> > > > if (mem_cgroup_try_charge_swap(page, entry)) {
> > > > put_swap_page(page, entry);
> > > > diff --git a/mm/swapfile.c b/mm/swapfile.c
> > > > index 63c61f8b2611..151fffe0fd60 100644
> > > > --- a/mm/swapfile.c
> > > > +++ b/mm/swapfile.c
> > > > @@ -1036,13 +1036,13 @@ static void swap_free_cluster(struct swap_info_struct *si, unsigned long idx)
> > > > swap_range_free(si, offset, SWAPFILE_CLUSTER);
> > > > }
> > > >
> > > > -int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
> > > > +int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size,
> > > > + int node)
> > > > {
> > > > unsigned long size = swap_entry_size(entry_size);
> > > > struct swap_info_struct *si, *next;
> > > > long avail_pgs;
> > > > int n_ret = 0;
> > > > - int node;
> > > >
> > > > /* Only single cluster request supported */
> > > > WARN_ON_ONCE(n_goal > 1 && size == SWAPFILE_CLUSTER);
> > > > @@ -1060,7 +1060,6 @@ int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
> > > > atomic_long_sub(n_goal * size, &nr_swap_pages);
> > > >
> > > > start_over:
> > > > - node = numa_node_id();
> > > > plist_for_each_entry_safe(si, next, &swap_avail_heads[node], avail_lists[node]) {
> > > > /* requeue si to after same-priority siblings */
> > > > plist_requeue(&si->avail_lists[node], &swap_avail_heads[node]);
> > > > --
> > > > 2.26.3
> > > >
> > > >
> >
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-20 22:21 ` Yang Shi
@ 2022-04-21 7:34 ` Aaron Lu
0 siblings, 0 replies; 23+ messages in thread
From: Aaron Lu @ 2022-04-21 7:34 UTC (permalink / raw)
To: Yang Shi
Cc: Huang Ying, Michal Hocko, Andrew Morton, Linux MM,
Linux Kernel Mailing List
On Wed, Apr 20, 2022 at 03:21:25PM -0700, Yang Shi wrote:
> On Wed, Apr 20, 2022 at 1:33 AM Aaron Lu <aaron.lu@intel.com> wrote:
> >
> > On Thu, Apr 07, 2022 at 10:36:54AM -0700, Yang Shi wrote:
> > > On Thu, Apr 7, 2022 at 1:12 AM Aaron Lu <aaron.lu@intel.com> wrote:
> > > >
> > > > On Wed, Apr 06, 2022 at 07:09:53PM -0700, Yang Shi wrote:
> > > > > The swap devices are linked to per node priority lists, the swap device
> > > > > closer to the node has higher priority on that node's priority list.
> > > > > This is supposed to improve I/O latency, particularly for some fast
> > > > > devices. But the current code gets nid by calling numa_node_id() which
> > > > > actually returns the nid that the reclaimer is running on instead of the
> > > > > nid that the page belongs to.
> > > > >
> > > >
> > > > Right.
> > > >
> > > > > Pass the page's nid dow to get_swap_pages() in order to pick up the
> > > > > right swap device. But it doesn't work for the swap slots cache which
> > > > > is per cpu. We could skip swap slots cache if the current node is not
> > > > > the page's node, but it may be overkilling. So keep using the current
> > > > > node's swap slots cache. The issue was found by visual code inspection
> > > > > so it is not sure how much improvement could be achieved due to lack of
> > > > > suitable testing device. But anyway the current code does violate the
> > > > > design.
> > > > >
> > > >
> > > > I intentionally used the reclaimer's nid because I think when swapping
> > > > out to a device, it is faster when the device is on the same node as
> > > > the cpu.
> > >
> > > OK, the offline discussion with Huang Ying showed the design was to
> > > have page's nid in order to achieve better I/O performance (more
> > > noticeable on faster devices) since the reclaimer may be running on a
> > > different node from the reclaimed page.
> > >
> > > >
> > > > Anyway, I think I can make a test case where the workload allocates all
> > > > its memory on the remote node and its workingset memory is larger then
> > > > the available memory so swap is triggered, then we can see which way
> > > > achieves better performance. Sounds reasonable to you?
> > >
> > > Yeah, definitely, thank you so much. I don't have a fast enough device
> > > by hand to show the difference right now. If you could get some data
> > > it would be perfect.
> > >
> >
> > Failed to find a test box that has two NVMe disks attached to different
> > nodes and since Shanghai is locked down right now, we couldn't install
> > another NVMe on the box so I figured it might be OK to test on a box that
> > has a single NVMe attached to node 0 like this:
> >
> > 1) restrict the test processes to run on node 0 and allocate on node 1;
> > 2) restrict the test processes to run on node 1 and allocate on node 0.
> >
> > In case 1), the reclaimer's node id is the same as the swap device's so
> > it's the same as current behaviour and in case 2), the page's node id is
> > the same as the swap device's so it's what your patch proposed.
> >
> > The test I used is vm-scalability/case-swap-w-rand:
> > https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/tree/case-swap-w-seq
> > which spawns $nr_task processes and each will mmap $size and then
> > randomly write to that area. I set nr_task=32 and $size=4G, so a total
> > of 128G memory will be needed and I used memory.limit_in_bytes to
> > restrict the available memory to 64G, to make sure swap is triggered.
> >
> > The reason why cgroup is used is to avoid waking up the per-node kswapd
> > which can trigger swapping with reclaimer/page/swap device all having the
> > same node id.
> >
> > And I don't see a measuable difference from the result:
> > case1(using reclaimer's node id) vm-scalability.throughput: 10574 KB/s
> > case2(using page's node id) vm-scalability.throughput: 10567 KB/s
> >
> > My interpretation of the result is, when reclaiming a remote page, it
> > doesn't matter much which swap device to use if the swap device is a IO
> > device.
> >
> > Later Ying reminded me we have test box that has optane installed on
> > different nodes so I also tested there: Icelake 2 sockets server with 2
> > optane installed on each node. I did the test there like this:
> > 1) restrict the test processes to run on node 0 and allocate on node 1
> > and only swapon pmem0, which is the optane backed swap device on node 0;
> > 2) restrict the test processes to run on node 0 and allocate on node 1
> > and only swapon pmem1, which is the optane backed swap device on node 1.
> >
> > So case 1) is current behaviour and case 2) is what your patch proposed.
> >
> > With the same test and the same nr_task/size, the result is:
> > case1(using reclaimer's node id) vm-scalability.throughput: 71033 KB/s
> > case2(using page's node id) vm-scalability.throughput: 58753 KB/s
> >
> > The result suggested when using a memory like device as swap device,
> > it's better to use the reclaimer's node id when swapping.
> >
> > What do you think of these tests and results?
>
> Thanks, Aaron. Since you are using PMEM so I'm supposed case #2
> actually has 1 more cross node memory copy than case #1. Swapping
> doesn't incur the block I/O (DMA) but memory copy in this
> configuration.
>
Right.
> IIUC, case #1 would do node1 -> node0 -> pmem0, but case #2 would do
> node1 -> node0 -> pmem1.
>
I think so.
> Actually I was thinking about Optane SSD instead of PMEM when
> discussing this with Ying offline. Not sure if Optane SSD would have
> any measurable difference or not. But anyway if PMEM is used as swap
> device the current implementation does make more sense.
>
LKP lab doesn't have any machine with Optane SSD, will let you know if
I managed to find one elsewhere and get some results.
In the meantime, I think testing on Optane SSD might make more sense
since there is the memory tiering support for Optane DIMM and swap may
not be used there but for the SSD, it has a higher chance of being used
as swap.
Thanks,
Aaron
> > > BTW, this patch doesn't change the node for swap slots cache, so it
> > > may still use the swap device on a remote node if swap slots cache is
> > > used.
> > >
> > > >
> > > > > Cc: Huang Ying <ying.huang@intel.com>
> > > > > Signed-off-by: Yang Shi <shy828301@gmail.com>
> > > > > ---
> > > > > include/linux/swap.h | 3 ++-
> > > > > mm/swap_slots.c | 7 ++++---
> > > > > mm/swapfile.c | 5 ++---
> > > > > 3 files changed, 8 insertions(+), 7 deletions(-)
> > > > >
> > > > > diff --git a/include/linux/swap.h b/include/linux/swap.h
> > > > > index 27093b477c5f..e442cf6b61ea 100644
> > > > > --- a/include/linux/swap.h
> > > > > +++ b/include/linux/swap.h
> > > > > @@ -497,7 +497,8 @@ extern void si_swapinfo(struct sysinfo *);
> > > > > extern swp_entry_t get_swap_page(struct page *page);
> > > > > extern void put_swap_page(struct page *page, swp_entry_t entry);
> > > > > extern swp_entry_t get_swap_page_of_type(int);
> > > > > -extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size);
> > > > > +extern int get_swap_pages(int n, swp_entry_t swp_entries[], int entry_size,
> > > > > + int node);
> > > > > extern int add_swap_count_continuation(swp_entry_t, gfp_t);
> > > > > extern void swap_shmem_alloc(swp_entry_t);
> > > > > extern int swap_duplicate(swp_entry_t);
> > > > > diff --git a/mm/swap_slots.c b/mm/swap_slots.c
> > > > > index 2b5531840583..a1c5cf6a4302 100644
> > > > > --- a/mm/swap_slots.c
> > > > > +++ b/mm/swap_slots.c
> > > > > @@ -264,7 +264,7 @@ static int refill_swap_slots_cache(struct swap_slots_cache *cache)
> > > > > cache->cur = 0;
> > > > > if (swap_slot_cache_active)
> > > > > cache->nr = get_swap_pages(SWAP_SLOTS_CACHE_SIZE,
> > > > > - cache->slots, 1);
> > > > > + cache->slots, 1, numa_node_id());
> > > > >
> > > > > return cache->nr;
> > > > > }
> > > > > @@ -305,12 +305,13 @@ swp_entry_t get_swap_page(struct page *page)
> > > > > {
> > > > > swp_entry_t entry;
> > > > > struct swap_slots_cache *cache;
> > > > > + int nid = page_to_nid(page);
> > > > >
> > > > > entry.val = 0;
> > > > >
> > > > > if (PageTransHuge(page)) {
> > > > > if (IS_ENABLED(CONFIG_THP_SWAP))
> > > > > - get_swap_pages(1, &entry, HPAGE_PMD_NR);
> > > > > + get_swap_pages(1, &entry, HPAGE_PMD_NR, nid);
> > > > > goto out;
> > > > > }
> > > > >
> > > > > @@ -342,7 +343,7 @@ swp_entry_t get_swap_page(struct page *page)
> > > > > goto out;
> > > > > }
> > > > >
> > > > > - get_swap_pages(1, &entry, 1);
> > > > > + get_swap_pages(1, &entry, 1, nid);
> > > > > out:
> > > > > if (mem_cgroup_try_charge_swap(page, entry)) {
> > > > > put_swap_page(page, entry);
> > > > > diff --git a/mm/swapfile.c b/mm/swapfile.c
> > > > > index 63c61f8b2611..151fffe0fd60 100644
> > > > > --- a/mm/swapfile.c
> > > > > +++ b/mm/swapfile.c
> > > > > @@ -1036,13 +1036,13 @@ static void swap_free_cluster(struct swap_info_struct *si, unsigned long idx)
> > > > > swap_range_free(si, offset, SWAPFILE_CLUSTER);
> > > > > }
> > > > >
> > > > > -int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
> > > > > +int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size,
> > > > > + int node)
> > > > > {
> > > > > unsigned long size = swap_entry_size(entry_size);
> > > > > struct swap_info_struct *si, *next;
> > > > > long avail_pgs;
> > > > > int n_ret = 0;
> > > > > - int node;
> > > > >
> > > > > /* Only single cluster request supported */
> > > > > WARN_ON_ONCE(n_goal > 1 && size == SWAPFILE_CLUSTER);
> > > > > @@ -1060,7 +1060,6 @@ int get_swap_pages(int n_goal, swp_entry_t swp_entries[], int entry_size)
> > > > > atomic_long_sub(n_goal * size, &nr_swap_pages);
> > > > >
> > > > > start_over:
> > > > > - node = numa_node_id();
> > > > > plist_for_each_entry_safe(si, next, &swap_avail_heads[node], avail_lists[node]) {
> > > > > /* requeue si to after same-priority siblings */
> > > > > plist_requeue(&si->avail_lists[node], &swap_avail_heads[node]);
> > > > > --
> > > > > 2.26.3
> > > > >
> > > > >
> > >
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-20 8:33 ` Aaron Lu
2022-04-20 22:21 ` Yang Shi
@ 2022-04-21 7:49 ` ying.huang
2022-04-21 8:17 ` Aaron Lu
2022-04-21 14:11 ` Aaron Lu
1 sibling, 2 replies; 23+ messages in thread
From: ying.huang @ 2022-04-21 7:49 UTC (permalink / raw)
To: Aaron Lu, Yang Shi
Cc: Michal Hocko, Andrew Morton, Linux MM, Linux Kernel Mailing List
On Wed, 2022-04-20 at 16:33 +0800, Aaron Lu wrote:
> On Thu, Apr 07, 2022 at 10:36:54AM -0700, Yang Shi wrote:
> > On Thu, Apr 7, 2022 at 1:12 AM Aaron Lu <aaron.lu@intel.com> wrote:
> > >
> > > On Wed, Apr 06, 2022 at 07:09:53PM -0700, Yang Shi wrote:
> > > > The swap devices are linked to per node priority lists, the swap device
> > > > closer to the node has higher priority on that node's priority list.
> > > > This is supposed to improve I/O latency, particularly for some fast
> > > > devices. But the current code gets nid by calling numa_node_id() which
> > > > actually returns the nid that the reclaimer is running on instead of the
> > > > nid that the page belongs to.
> > > >
> > >
> > > Right.
> > >
> > > > Pass the page's nid dow to get_swap_pages() in order to pick up the
> > > > right swap device. But it doesn't work for the swap slots cache which
> > > > is per cpu. We could skip swap slots cache if the current node is not
> > > > the page's node, but it may be overkilling. So keep using the current
> > > > node's swap slots cache. The issue was found by visual code inspection
> > > > so it is not sure how much improvement could be achieved due to lack of
> > > > suitable testing device. But anyway the current code does violate the
> > > > design.
> > > >
> > >
> > > I intentionally used the reclaimer's nid because I think when swapping
> > > out to a device, it is faster when the device is on the same node as
> > > the cpu.
> >
> > OK, the offline discussion with Huang Ying showed the design was to
> > have page's nid in order to achieve better I/O performance (more
> > noticeable on faster devices) since the reclaimer may be running on a
> > different node from the reclaimed page.
> >
> > >
> > > Anyway, I think I can make a test case where the workload allocates all
> > > its memory on the remote node and its workingset memory is larger then
> > > the available memory so swap is triggered, then we can see which way
> > > achieves better performance. Sounds reasonable to you?
> >
> > Yeah, definitely, thank you so much. I don't have a fast enough device
> > by hand to show the difference right now. If you could get some data
> > it would be perfect.
> >
>
> Failed to find a test box that has two NVMe disks attached to different
> nodes and since Shanghai is locked down right now, we couldn't install
> another NVMe on the box so I figured it might be OK to test on a box that
> has a single NVMe attached to node 0 like this:
>
> 1) restrict the test processes to run on node 0 and allocate on node 1;
> 2) restrict the test processes to run on node 1 and allocate on node 0.
>
> In case 1), the reclaimer's node id is the same as the swap device's so
> it's the same as current behaviour and in case 2), the page's node id is
> the same as the swap device's so it's what your patch proposed.
>
> The test I used is vm-scalability/case-swap-w-rand:
> https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/tree/case-swap-w-seq
> which spawns $nr_task processes and each will mmap $size and then
> randomly write to that area. I set nr_task=32 and $size=4G, so a total
> of 128G memory will be needed and I used memory.limit_in_bytes to
> restrict the available memory to 64G, to make sure swap is triggered.
>
> The reason why cgroup is used is to avoid waking up the per-node kswapd
> which can trigger swapping with reclaimer/page/swap device all having the
> same node id.
>
> And I don't see a measuable difference from the result:
> case1(using reclaimer's node id) vm-scalability.throughput: 10574 KB/s
> case2(using page's node id) vm-scalability.throughput: 10567 KB/s
>
> My interpretation of the result is, when reclaiming a remote page, it
> doesn't matter much which swap device to use if the swap device is a IO
> device.
>
> Later Ying reminded me we have test box that has optane installed on
> different nodes so I also tested there: Icelake 2 sockets server with 2
> optane installed on each node. I did the test there like this:
> 1) restrict the test processes to run on node 0 and allocate on node 1
> and only swapon pmem0, which is the optane backed swap device on node 0;
> 2) restrict the test processes to run on node 0 and allocate on node 1
> and only swapon pmem1, which is the optane backed swap device on node 1.
>
> So case 1) is current behaviour and case 2) is what your patch proposed.
>
> With the same test and the same nr_task/size, the result is:
> case1(using reclaimer's node id) vm-scalability.throughput: 71033 KB/s
> case2(using page's node id) vm-scalability.throughput: 58753 KB/s
>
The per-node swap device support is more about swap-in latency than
swap-out throughput. I suspect the test case is more about swap-out
throughput. perf profiling can show this.
For swap-in latency, we can use pmbench, which can output latency
information.
Best Regards,
Huang, Ying
[snip]
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-21 7:49 ` ying.huang
@ 2022-04-21 8:17 ` Aaron Lu
2022-04-21 8:30 ` Aaron Lu
2022-04-21 8:34 ` ying.huang
2022-04-21 14:11 ` Aaron Lu
1 sibling, 2 replies; 23+ messages in thread
From: Aaron Lu @ 2022-04-21 8:17 UTC (permalink / raw)
To: ying.huang
Cc: Yang Shi, Michal Hocko, Andrew Morton, Linux MM,
Linux Kernel Mailing List
On Thu, Apr 21, 2022 at 03:49:21PM +0800, ying.huang@intel.com wrote:
> On Wed, 2022-04-20 at 16:33 +0800, Aaron Lu wrote:
> > On Thu, Apr 07, 2022 at 10:36:54AM -0700, Yang Shi wrote:
> > > On Thu, Apr 7, 2022 at 1:12 AM Aaron Lu <aaron.lu@intel.com> wrote:
> > > >
> > > > On Wed, Apr 06, 2022 at 07:09:53PM -0700, Yang Shi wrote:
> > > > > The swap devices are linked to per node priority lists, the swap device
> > > > > closer to the node has higher priority on that node's priority list.
> > > > > This is supposed to improve I/O latency, particularly for some fast
> > > > > devices. But the current code gets nid by calling numa_node_id() which
> > > > > actually returns the nid that the reclaimer is running on instead of the
> > > > > nid that the page belongs to.
> > > > >
> > > >
> > > > Right.
> > > >
> > > > > Pass the page's nid dow to get_swap_pages() in order to pick up the
> > > > > right swap device. But it doesn't work for the swap slots cache which
> > > > > is per cpu. We could skip swap slots cache if the current node is not
> > > > > the page's node, but it may be overkilling. So keep using the current
> > > > > node's swap slots cache. The issue was found by visual code inspection
> > > > > so it is not sure how much improvement could be achieved due to lack of
> > > > > suitable testing device. But anyway the current code does violate the
> > > > > design.
> > > > >
> > > >
> > > > I intentionally used the reclaimer's nid because I think when swapping
> > > > out to a device, it is faster when the device is on the same node as
> > > > the cpu.
> > >
> > > OK, the offline discussion with Huang Ying showed the design was to
> > > have page's nid in order to achieve better I/O performance (more
> > > noticeable on faster devices) since the reclaimer may be running on a
> > > different node from the reclaimed page.
> > >
> > > >
> > > > Anyway, I think I can make a test case where the workload allocates all
> > > > its memory on the remote node and its workingset memory is larger then
> > > > the available memory so swap is triggered, then we can see which way
> > > > achieves better performance. Sounds reasonable to you?
> > >
> > > Yeah, definitely, thank you so much. I don't have a fast enough device
> > > by hand to show the difference right now. If you could get some data
> > > it would be perfect.
> > >
> >
> > Failed to find a test box that has two NVMe disks attached to different
> > nodes and since Shanghai is locked down right now, we couldn't install
> > another NVMe on the box so I figured it might be OK to test on a box that
> > has a single NVMe attached to node 0 like this:
> >
> > 1) restrict the test processes to run on node 0 and allocate on node 1;
> > 2) restrict the test processes to run on node 1 and allocate on node 0.
> >
> > In case 1), the reclaimer's node id is the same as the swap device's so
> > it's the same as current behaviour and in case 2), the page's node id is
> > the same as the swap device's so it's what your patch proposed.
> >
> > The test I used is vm-scalability/case-swap-w-rand:
> > https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/tree/case-swap-w-seq
> > which spawns $nr_task processes and each will mmap $size and then
> > randomly write to that area. I set nr_task=32 and $size=4G, so a total
> > of 128G memory will be needed and I used memory.limit_in_bytes to
> > restrict the available memory to 64G, to make sure swap is triggered.
> >
> > The reason why cgroup is used is to avoid waking up the per-node kswapd
> > which can trigger swapping with reclaimer/page/swap device all having the
> > same node id.
> >
> > And I don't see a measuable difference from the result:
> > case1(using reclaimer's node id) vm-scalability.throughput: 10574 KB/s
> > case2(using page's node id) vm-scalability.throughput: 10567 KB/s
> >
> > My interpretation of the result is, when reclaiming a remote page, it
> > doesn't matter much which swap device to use if the swap device is a IO
> > device.
> >
> > Later Ying reminded me we have test box that has optane installed on
> > different nodes so I also tested there: Icelake 2 sockets server with 2
> > optane installed on each node. I did the test there like this:
> > 1) restrict the test processes to run on node 0 and allocate on node 1
> > and only swapon pmem0, which is the optane backed swap device on node 0;
> > 2) restrict the test processes to run on node 0 and allocate on node 1
> > and only swapon pmem1, which is the optane backed swap device on node 1.
> >
> > So case 1) is current behaviour and case 2) is what your patch proposed.
> >
> > With the same test and the same nr_task/size, the result is:
> > case1(using reclaimer's node id) vm-scalability.throughput: 71033 KB/s
> > case2(using page's node id) vm-scalability.throughput: 58753 KB/s
> >
>
> The per-node swap device support is more about swap-in latency than
> swap-out throughput. I suspect the test case is more about swap-out
> throughput. perf profiling can show this.
>
Can you elaborate the "perf profiling" part, like which perf metric can
show this?
I checked the vmstat output. Initially, it's mostly swap out, then swap
in starts to be more and more, but swapout is always more than swapin.
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- -----timestamp-----
r b swpd free buff cache si so bi bo in cs us sy id wa st UTC
20 0 0 259772032 8 2428796 0 0 2 0 365 74 1 1 98 0 0 2022-04-19 11:44:37
4 0 0 259149824 8 2439084 0 0 0 0 148536 22298 1 3 96 0 0 2022-04-19 11:44:38
35 0 0 236926192 1052 2572000 0 0 2163 2048 392940 3690 1 24 75 0 0 2022-04-19 11:44:39
32 0 0 205170832 1052 2572280 0 0 0 0 193095 1280 2 33 65 0 0 2022-04-19 11:44:40
40 0 136448 192211008 1052 2439412 268 133760 0 0 532052 3571 0 40 59 0 0 2022-04-19 11:44:43
33 0 4224000 192182464 1052 2450936 130636 4211460 0 0 1145644 15600 1 33 65 0 0 2022-04-19 11:44:44
32 0 6908708 192179408 1052 2460836 239456 2924392 0 0 863325 10731 1 34 65 0 0 2022-04-19 11:44:45
33 0 9005036 192163936 1052 2469112 279200 2371924 0 0 739330 9635 1 34 65 0 0 2022-04-19 11:44:46
32 0 10769408 192154864 1052 2476172 305516 2071440 0 0 673619 9044 1 34 65 0 0 2022-04-19 11:44:47
32 0 12318720 192149344 1052 2482708 324312 1875224 0 0 627868 9404 1 35 65 0 0 2022-04-19 11:44:48
33 0 13735796 192146752 1052 2488520 340684 1756308 0 0 601933 11815 1 35 65 0 0 2022-04-19 11:44:49
... ...
32 0 47465984 192000400 1052 2636472 456228 652756 0 0 335570 4359 0 35 65 0 0 2022-04-19 11:46:11
33 0 47652352 191996784 1052 2637932 437368 622652 0 0 328532 3627 1 35 65 0 0 2022-04-19 11:46:12
33 0 47830272 191998800 1052 2639296 428224 607516 0 0 325651 3847 1 35 65 0 0 2022-04-19 11:46:13
34 0 48014492 192001504 1052 2640596 441592 625308 0 0 329752 4199 1 35 65 0 0 2022-04-19 11:46:14
32 0 48200960 191996240 1052 2642148 458724 645744 0 0 333806 3988 0 35 65 0 0 2022-04-19 11:46:15
45 0 48379904 191991904 1052 2643576 442948 621268 0 0 329070 4529 0 35 65 0 0 2022-04-19 11:46:16
33 0 48557504 191996960 1052 2644812 444420 621948 0 0 328916 7249 1 35 64 0 0 2022-04-19 11:46:17
33 0 48729564 191995744 1052 2646272 447396 619376 0 0 329126 4565 0 35 65 0 0 2022-04-19 11:46:18
32 0 48959268 191989024 1052 2647828 595888 825480 0 0 368714 8096 0 35 65 0 0 2022-04-19 11:46:19
32 0 49242368 191990304 1052 2650036 746212 1028524 0 0 411140 10949 0 34 65 0 0 2022-04-19 11:46:20
32 0 49520792 191984080 1052 2652372 758208 1037236 0 0 415505 10094 0 34 65 0 0 2022-04-19 11:46:21
32 0 49799168 191994240 1052 2654724 767236 1046964 0 0 418405 10726 0 35 65 0 0 2022-04-19 11:46:22
32 0 50067712 191989104 1052 2657092 759192 1028600 0 0 415356 10173 0 35 65 0 0 2022-04-19 11:46:23
33 0 50333440 191980320 1052 2659332 750764 1014732 0 0 412144 9197 0 34 65 0 0 2022-04-19 11:46:24
32 0 50584052 191973824 1052 2661576 737720 988964 0 0 406620 8752 0 35 65 0 0 2022-04-19 11:46:25
32 0 50816000 191976080 1052 2663660 689248 921108 0 0 391782 8517 0 34 65 0 0 2022-04-19 11:46:26
32 0 51036416 191970464 1052 2665612 668004 888220 0 0 385112 7310 1 34 65 0 0 2022-04-19 11:46:27
32 0 51256576 191962224 1052 2667536 678464 897872 0 0 388494 12547 0 35 65 0 0 2022-04-19 11:46:28
33 0 51464680 191966304 1052 2669472 654540 862720 0 0 380869 7069 1 34 65 0 0 2022-04-19 11:46:29
32 0 51597232 191971840 1052 2670848 419772 552324 0 0 314325 4029 1 35 65 0 0 2022-04-19 11:46:30
33 0 51722448 191969456 1052 2672072 409300 535892 0 0 310720 4014 1 35 65 0 0 2022-04-19 11:46:31
32 0 51850496 191963472 1052 2673236 413160 541076 0 0 311652 3583 1 35 65 0 0 2022-04-19 11:46:32
32 0 51978872 191968208 1052 2674452 415844 543464 0 0 312411 3579 1 35 65 0 0 2022-04-19 11:46:33
32 0 52105724 191974640 1052 2675616 418104 545728 0 0 312731 4183 1 35 65 0 0 2022-04-19 11:46:34
34 0 52232928 191964336 1052 2676964 426200 552956 0 0 314230 3834 1 35 64 0 0 2022-04-19 11:46:35
The full vmstat is attached.
> For swap-in latency, we can use pmbench, which can output latency
> information.
>
OK, I'll give pmbench a run, thanks for the suggestion.
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-21 8:17 ` Aaron Lu
@ 2022-04-21 8:30 ` Aaron Lu
2022-04-21 8:34 ` ying.huang
1 sibling, 0 replies; 23+ messages in thread
From: Aaron Lu @ 2022-04-21 8:30 UTC (permalink / raw)
To: ying.huang
Cc: Yang Shi, Michal Hocko, Andrew Morton, Linux MM,
Linux Kernel Mailing List
[-- Attachment #1: Type: text/plain, Size: 114 bytes --]
On Thu, Apr 21, 2022 at 04:17:20PM +0800, Aaron Lu wrote:
> The full vmstat is attached.
Now really attach it.
[-- Attachment #2: vmstat --]
[-- Type: text/plain, Size: 36403 bytes --]
procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- -----timestamp-----
r b swpd free buff cache si so bi bo in cs us sy id wa st UTC
20 0 0 259772032 8 2428796 0 0 2 0 365 74 1 1 98 0 0 2022-04-19 11:44:37
4 0 0 259149824 8 2439084 0 0 0 0 148536 22298 1 3 96 0 0 2022-04-19 11:44:38
35 0 0 236926192 1052 2572000 0 0 2163 2048 392940 3690 1 24 75 0 0 2022-04-19 11:44:39
32 0 0 205170832 1052 2572280 0 0 0 0 193095 1280 2 33 65 0 0 2022-04-19 11:44:40
40 0 136448 192211008 1052 2439412 268 133760 0 0 532052 3571 0 40 59 0 0 2022-04-19 11:44:43
33 0 4224000 192182464 1052 2450936 130636 4211460 0 0 1145644 15600 1 33 65 0 0 2022-04-19 11:44:44
32 0 6908708 192179408 1052 2460836 239456 2924392 0 0 863325 10731 1 34 65 0 0 2022-04-19 11:44:45
33 0 9005036 192163936 1052 2469112 279200 2371924 0 0 739330 9635 1 34 65 0 0 2022-04-19 11:44:46
32 0 10769408 192154864 1052 2476172 305516 2071440 0 0 673619 9044 1 34 65 0 0 2022-04-19 11:44:47
32 0 12318720 192149344 1052 2482708 324312 1875224 0 0 627868 9404 1 35 65 0 0 2022-04-19 11:44:48
33 0 13735796 192146752 1052 2488520 340684 1756308 0 0 601933 11815 1 35 65 0 0 2022-04-19 11:44:49
32 0 14987008 192136848 1052 2493692 338980 1590408 0 0 563875 9375 0 35 65 0 0 2022-04-19 11:44:50
32 0 16168012 192133232 1052 2497264 356736 1537696 0 0 550767 8588 0 35 65 0 0 2022-04-19 11:44:51
38 0 17286860 192132976 1052 2500684 367600 1484368 0 0 539362 8312 0 35 64 0 0 2022-04-19 11:44:52
32 0 18316660 192128032 1052 2503832 371648 1402320 0 0 519531 7857 0 35 64 0 0 2022-04-19 11:44:53
32 0 19272448 192129216 1052 2506756 371268 1328540 0 0 503122 7764 0 35 64 0 0 2022-04-19 11:44:54
32 0 20186880 192130432 1052 2509720 378588 1291684 0 0 493909 8058 0 35 64 0 0 2022-04-19 11:44:55
32 0 21039076 192117904 1052 2512484 374920 1227208 0 0 479430 7614 0 35 64 0 0 2022-04-19 11:44:56
32 0 21858304 192117088 1052 2515292 382228 1202388 0 0 471800 7280 0 35 64 0 0 2022-04-19 11:44:57
32 0 22643200 192124736 1052 2517928 387796 1172604 0 0 466398 7560 0 35 65 0 0 2022-04-19 11:44:58
33 0 23398400 192121600 1052 2520604 390640 1145040 0 0 460020 7418 0 35 64 0 0 2022-04-19 11:44:59
32 0 24123904 192112128 1052 2523012 395544 1121908 0 0 454250 8995 0 35 64 0 0 2022-04-19 11:45:00
32 0 24812544 192110688 1052 2525400 391548 1080432 0 0 444148 7033 0 35 64 0 0 2022-04-19 11:45:01
32 0 25488384 192117024 1052 2527692 400572 1075560 0 0 442662 6579 0 35 64 0 0 2022-04-19 11:45:02
32 0 26136832 192110320 1052 2530144 400304 1048956 0 0 436651 6948 0 35 64 0 0 2022-04-19 11:45:03
33 0 26739968 192101152 1052 2532308 387808 991508 0 0 424139 6472 0 35 64 0 0 2022-04-19 11:45:04
33 0 27336960 192101264 1052 2534664 399084 994436 0 0 424789 5971 0 35 65 0 0 2022-04-19 11:45:05
32 0 27913984 192097264 1052 2536828 405424 984452 0 0 422030 7022 0 35 65 0 0 2022-04-19 11:45:06
32 0 28471320 192096368 1052 2538992 400360 956228 0 0 415233 6218 0 35 65 0 0 2022-04-19 11:45:07
32 0 29014996 192098080 1052 2541156 405664 949256 0 0 413223 5887 0 35 65 0 0 2022-04-19 11:45:08
32 0 29552008 192101648 1052 2543160 411052 947328 0 0 412808 6380 0 35 65 0 0 2022-04-19 11:45:09
32 0 30064896 192088528 1052 2545420 407592 921552 0 0 406967 6345 0 35 65 0 0 2022-04-19 11:45:10
32 0 30552576 192095616 1052 2547456 401472 889236 0 0 399464 8367 0 35 64 0 0 2022-04-19 11:45:11
32 0 31047240 192089856 1052 2549468 410644 905400 0 0 402550 5844 0 35 64 0 0 2022-04-19 11:45:12
33 0 31517184 192085856 1052 2551408 404460 874228 0 0 396451 5421 0 35 65 0 0 2022-04-19 11:45:13
34 0 31978240 192083072 1052 2553416 409600 869384 0 0 394614 5446 0 35 65 0 0 2022-04-19 11:45:14
32 0 32425736 192085152 1052 2555392 409288 857792 0 0 391189 5814 0 35 65 0 0 2022-04-19 11:45:15
33 0 32862464 192084688 1052 2557220 408200 846504 0 0 389040 5559 0 35 65 0 0 2022-04-19 11:45:16
33 0 33294336 192081376 1052 2559160 411612 842348 0 0 387955 5365 0 35 65 0 0 2022-04-19 11:45:17
35 0 33543936 192083728 1052 2560164 243240 492000 0 0 303579 4348 0 36 64 0 0 2022-04-19 11:45:18
33 0 33664000 192076384 1052 2557780 123344 245628 0 0 248236 7239 0 35 65 0 0 2022-04-19 11:45:19
32 0 33903616 192073632 1052 2558656 238444 476044 0 0 298068 10021 0 35 65 0 0 2022-04-19 11:45:20
32 0 34211840 192074656 1052 2559936 312412 621668 0 0 328435 11145 0 35 65 0 0 2022-04-19 11:45:21
32 0 34591232 192076096 1052 2561372 394416 773060 0 0 361995 17880 0 35 65 0 0 2022-04-19 11:45:22
32 0 34982892 192078448 1052 2563084 415324 806380 0 0 364197 9191 0 35 65 0 0 2022-04-19 11:45:23
32 0 35336192 192070560 1052 2564896 387108 740976 0 0 347194 6913 1 35 64 0 0 2022-04-19 11:45:24
32 0 35684292 192063200 1052 2566456 388180 737152 0 0 344533 6515 1 35 65 0 0 2022-04-19 11:45:25
32 0 36022272 192069504 1052 2568124 387496 724860 0 0 345241 6748 1 35 64 0 0 2022-04-19 11:45:26
32 0 36363260 192065792 1052 2569616 395840 736144 0 0 345187 6788 1 35 64 0 0 2022-04-19 11:45:27
33 0 36706040 192066336 1052 2571396 400132 742736 0 0 346808 6949 1 35 65 0 0 2022-04-19 11:45:28
33 0 37038336 192070896 1052 2573024 398784 731400 0 0 345257 6885 1 35 65 0 0 2022-04-19 11:45:29
32 0 37359060 192057488 1052 2574692 391968 712276 0 0 341340 7042 1 35 64 0 0 2022-04-19 11:45:30
33 0 37682984 192062400 1052 2576288 402508 726868 0 0 345344 6322 1 35 64 0 0 2022-04-19 11:45:31
33 0 38000480 192061392 1052 2578008 406472 724020 0 0 345762 6101 1 35 65 0 0 2022-04-19 11:45:32
32 0 38314240 192057920 1052 2579628 404624 719564 0 0 346545 9113 1 35 64 0 0 2022-04-19 11:45:33
32 0 38620848 192056288 1052 2581060 400092 705276 0 0 342857 6286 1 35 65 0 0 2022-04-19 11:45:34
33 0 38924100 192048960 1052 2582872 407892 711728 0 0 344675 5944 1 35 65 0 0 2022-04-19 11:45:35
34 0 39227136 192049040 1052 2584328 414916 718080 0 0 346432 5876 0 35 65 0 0 2022-04-19 11:45:36
33 0 39524352 192054880 1052 2585864 414464 711448 0 0 345906 5617 1 35 65 0 0 2022-04-19 11:45:37
32 0 39814656 192051152 1052 2587584 413760 704364 0 0 345164 5721 1 35 64 0 0 2022-04-19 11:45:38
32 0 40102912 192048160 1052 2589192 419172 707624 0 0 345399 5958 1 35 64 0 0 2022-04-19 11:45:39
32 0 40385024 192053840 1052 2590736 413372 694996 0 0 343269 5693 1 35 65 0 0 2022-04-19 11:45:40
33 0 40660992 192048464 1052 2592256 410276 685828 0 0 341024 5834 1 35 64 0 0 2022-04-19 11:45:41
32 0 40934824 192047104 1052 2594056 415724 690372 0 0 342278 5610 1 35 65 0 0 2022-04-19 11:45:42
33 0 41202688 192039152 1052 2595500 415360 683608 0 0 340834 5364 1 35 64 0 0 2022-04-19 11:45:43
33 0 41468672 192036176 1052 2596960 414772 681164 0 0 340613 7086 1 35 65 0 0 2022-04-19 11:45:44
32 0 41731300 192044352 1052 2598548 418424 680864 0 0 340310 4869 0 35 65 0 0 2022-04-19 11:45:45
34 0 41985536 192045344 1052 2599936 410740 664820 0 0 337015 5269 0 35 64 0 0 2022-04-19 11:45:46
34 0 42247168 192039040 1052 2601564 421728 682512 0 0 340811 5084 1 35 64 0 0 2022-04-19 11:45:47
33 0 42494464 192033776 1052 2602992 415476 663552 0 0 337414 5131 1 35 65 0 0 2022-04-19 11:45:48
32 0 42743208 192041968 1052 2604440 418868 667060 0 0 338061 5412 1 35 65 0 0 2022-04-19 11:45:49
33 0 42988028 192031264 1052 2605988 419984 664648 0 0 338247 5071 1 35 64 0 0 2022-04-19 11:45:50
32 0 43228672 192025952 1052 2607448 420752 661024 0 0 336313 5023 1 35 65 0 0 2022-04-19 11:45:51
32 0 43465472 192029056 1052 2609036 422256 658448 0 0 337030 4755 1 35 65 0 0 2022-04-19 11:45:52
36 0 43698612 192035056 1052 2610400 419936 652968 0 0 335086 4965 1 35 65 0 0 2022-04-19 11:45:53
32 0 43927040 192025616 1052 2611780 423080 652236 0 0 334524 4916 1 35 65 0 0 2022-04-19 11:45:54
32 0 44154296 192031552 1052 2613336 424208 652244 0 0 335620 7246 1 35 65 0 0 2022-04-19 11:45:55
33 0 44382400 192032768 1052 2614744 424424 651764 0 0 334836 4910 1 35 65 0 0 2022-04-19 11:45:56
32 0 44603572 192024896 1052 2616300 424524 646812 0 0 333817 4746 1 35 65 0 0 2022-04-19 11:45:57
34 0 44824536 192017776 1052 2617824 424004 645208 0 0 333903 4849 0 35 65 0 0 2022-04-19 11:45:58
33 0 45042408 192013952 1052 2619220 425432 641608 0 0 333238 4385 1 35 65 0 0 2022-04-19 11:45:59
32 0 45256192 192025280 1052 2620744 427912 642272 0 0 332972 4623 1 35 65 0 0 2022-04-19 11:46:00
33 0 45469092 192016832 1052 2622140 430300 643596 0 0 332949 4404 0 35 65 0 0 2022-04-19 11:46:01
32 0 45678592 192020832 1052 2623476 430020 638260 0 0 331800 4702 0 35 65 0 0 2022-04-19 11:46:02
32 0 45885064 192018848 1052 2624920 433280 641444 0 0 332904 4472 1 35 65 0 0 2022-04-19 11:46:03
32 0 46088420 192015056 1052 2626328 427348 629260 0 0 330343 4283 1 35 65 0 0 2022-04-19 11:46:04
32 0 46291200 192016544 1052 2627884 434952 638604 0 0 332063 4095 1 35 65 0 0 2022-04-19 11:46:05
32 0 46491268 192017408 1052 2629328 432096 630900 0 0 331614 6342 1 35 64 0 0 2022-04-19 11:46:06
32 0 46686208 192012064 1052 2630664 432152 627820 0 0 329774 4026 1 35 65 0 0 2022-04-19 11:46:07
34 0 46883320 192007696 1052 2632060 436388 632728 0 0 330649 3777 1 35 65 0 0 2022-04-19 11:46:08
33 0 47075840 192002688 1052 2633584 444144 637528 0 0 331857 4110 0 35 65 0 0 2022-04-19 11:46:09
32 0 47269368 192008160 1052 2635012 442700 636132 0 0 331605 4237 0 35 65 0 0 2022-04-19 11:46:10
32 0 47465984 192000400 1052 2636472 456228 652756 0 0 335570 4359 0 35 65 0 0 2022-04-19 11:46:11
33 0 47652352 191996784 1052 2637932 437368 622652 0 0 328532 3627 1 35 65 0 0 2022-04-19 11:46:12
33 0 47830272 191998800 1052 2639296 428224 607516 0 0 325651 3847 1 35 65 0 0 2022-04-19 11:46:13
34 0 48014492 192001504 1052 2640596 441592 625308 0 0 329752 4199 1 35 65 0 0 2022-04-19 11:46:14
32 0 48200960 191996240 1052 2642148 458724 645744 0 0 333806 3988 0 35 65 0 0 2022-04-19 11:46:15
45 0 48379904 191991904 1052 2643576 442948 621268 0 0 329070 4529 0 35 65 0 0 2022-04-19 11:46:16
33 0 48557504 191996960 1052 2644812 444420 621948 0 0 328916 7249 1 35 64 0 0 2022-04-19 11:46:17
33 0 48729564 191995744 1052 2646272 447396 619376 0 0 329126 4565 0 35 65 0 0 2022-04-19 11:46:18
32 0 48959268 191989024 1052 2647828 595888 825480 0 0 368714 8096 0 35 65 0 0 2022-04-19 11:46:19
32 0 49242368 191990304 1052 2650036 746212 1028524 0 0 411140 10949 0 34 65 0 0 2022-04-19 11:46:20
32 0 49520792 191984080 1052 2652372 758208 1037236 0 0 415505 10094 0 34 65 0 0 2022-04-19 11:46:21
32 0 49799168 191994240 1052 2654724 767236 1046964 0 0 418405 10726 0 35 65 0 0 2022-04-19 11:46:22
32 0 50067712 191989104 1052 2657092 759192 1028600 0 0 415356 10173 0 35 65 0 0 2022-04-19 11:46:23
33 0 50333440 191980320 1052 2659332 750764 1014732 0 0 412144 9197 0 34 65 0 0 2022-04-19 11:46:24
32 0 50584052 191973824 1052 2661576 737720 988964 0 0 406620 8752 0 35 65 0 0 2022-04-19 11:46:25
32 0 50816000 191976080 1052 2663660 689248 921108 0 0 391782 8517 0 34 65 0 0 2022-04-19 11:46:26
32 0 51036416 191970464 1052 2665612 668004 888220 0 0 385112 7310 1 34 65 0 0 2022-04-19 11:46:27
32 0 51256576 191962224 1052 2667536 678464 897872 0 0 388494 12547 0 35 65 0 0 2022-04-19 11:46:28
33 0 51464680 191966304 1052 2669472 654540 862720 0 0 380869 7069 1 34 65 0 0 2022-04-19 11:46:29
32 0 51597232 191971840 1052 2670848 419772 552324 0 0 314325 4029 1 35 65 0 0 2022-04-19 11:46:30
33 0 51722448 191969456 1052 2672072 409300 535892 0 0 310720 4014 1 35 65 0 0 2022-04-19 11:46:31
32 0 51850496 191963472 1052 2673236 413160 541076 0 0 311652 3583 1 35 65 0 0 2022-04-19 11:46:32
32 0 51978872 191968208 1052 2674452 415844 543464 0 0 312411 3579 1 35 65 0 0 2022-04-19 11:46:33
32 0 52105724 191974640 1052 2675616 418104 545728 0 0 312731 4183 1 35 65 0 0 2022-04-19 11:46:34
34 0 52232928 191964336 1052 2676964 426200 552956 0 0 314230 3834 1 35 64 0 0 2022-04-19 11:46:35
32 0 52357120 191966016 1052 2678068 423264 548348 0 0 313803 3715 1 35 65 0 0 2022-04-19 11:46:36
32 0 52480000 191964416 1052 2679416 416128 538092 0 0 311067 3685 1 35 65 0 0 2022-04-19 11:46:37
32 0 52605616 191958880 1052 2680628 437608 563284 0 0 317485 4630 1 35 64 0 0 2022-04-19 11:46:38
33 0 52727808 191960976 1052 2681848 429192 552412 0 0 314454 6385 1 35 64 0 0 2022-04-19 11:46:39
33 0 52848384 191961280 1052 2683152 429448 550060 0 0 313430 3628 1 35 65 0 0 2022-04-19 11:46:40
33 0 52974848 191958400 1052 2684336 438688 562580 0 0 316278 3847 1 35 65 0 0 2022-04-19 11:46:41
34 0 53092340 191956512 1052 2685556 432780 551080 0 0 314084 3851 1 35 65 0 0 2022-04-19 11:46:42
35 0 53213544 191956800 1052 2686828 436968 557028 0 0 315585 4126 1 35 65 0 0 2022-04-19 11:46:43
34 0 53329860 191951392 1052 2688020 432704 548412 0 0 313339 3632 1 35 65 0 0 2022-04-19 11:46:44
32 0 53447936 191949632 1052 2689128 444180 563836 0 0 318195 3536 1 35 65 0 0 2022-04-19 11:46:45
33 0 53564160 191950816 1052 2690376 442124 558876 0 0 315715 4082 1 35 65 0 0 2022-04-19 11:46:46
32 0 53679224 191950992 1052 2691708 441260 556820 0 0 315667 3954 1 35 65 0 0 2022-04-19 11:46:47
32 0 53797116 191938592 1052 2693000 450788 567540 0 0 317665 3829 1 35 65 0 0 2022-04-19 11:46:48
32 0 53912832 191947792 1052 2694152 449472 565396 0 0 317678 4118 1 35 65 0 0 2022-04-19 11:46:49
32 0 54030456 191939680 1052 2695608 467288 585312 0 0 321126 5453 1 35 65 0 0 2022-04-19 11:46:50
35 0 54141632 191938944 1052 2696852 450124 561748 0 0 316831 3704 1 35 65 0 0 2022-04-19 11:46:51
32 0 54254592 191942000 1052 2698068 454148 566852 0 0 317321 3844 1 35 65 0 0 2022-04-19 11:46:52
32 0 54365692 191936912 1052 2699256 455204 565628 0 0 317220 3913 1 35 65 0 0 2022-04-19 11:46:53
32 0 54475620 191937120 1052 2700540 461644 573284 0 0 319328 3940 1 35 65 0 0 2022-04-19 11:46:54
33 0 54586568 191937568 1052 2701760 462000 573528 0 0 320352 4047 1 35 65 0 0 2022-04-19 11:46:55
33 0 54697728 191929904 1052 2702980 461904 571872 0 0 318957 3672 1 35 65 0 0 2022-04-19 11:46:56
33 0 54804480 191930528 1052 2704304 455672 562912 0 0 316782 3897 1 35 65 0 0 2022-04-19 11:46:57
32 0 54914816 191937440 1052 2705684 470056 579664 0 0 320349 4244 1 35 65 0 0 2022-04-19 11:46:58
32 0 55022712 191932704 1052 2706840 465760 572212 0 0 318664 3987 1 35 65 0 0 2022-04-19 11:46:59
32 0 55127296 191929632 1052 2708112 461364 566492 0 0 317456 4153 1 35 65 0 0 2022-04-19 11:47:00
34 0 55230288 191926416 1052 2709332 462920 565840 0 0 318217 6997 1 35 65 0 0 2022-04-19 11:47:01
35 0 55332752 191926096 1052 2710608 462300 565332 0 0 317071 4076 1 35 65 0 0 2022-04-19 11:47:02
32 0 55434748 191924736 1052 2711984 459936 561164 0 0 316499 3919 1 35 65 0 0 2022-04-19 11:47:03
32 0 55536896 191921376 1052 2713184 468912 572304 0 0 318619 4379 1 35 65 0 0 2022-04-19 11:47:04
34 0 55637304 191924000 1052 2714432 467428 567004 0 0 317671 3681 1 35 65 0 0 2022-04-19 11:47:05
33 0 55739392 191925216 1052 2715616 478372 581340 0 0 322587 4306 1 35 65 0 0 2022-04-19 11:47:06
32 0 55838940 191926048 1052 2717016 471368 570720 0 0 318479 4010 1 35 65 0 0 2022-04-19 11:47:07
33 0 55936368 191922352 1052 2718284 464848 562040 0 0 316348 4148 1 35 65 0 0 2022-04-19 11:47:08
34 0 56032256 191919664 1052 2719488 464940 561024 0 0 316491 3988 1 35 65 0 0 2022-04-19 11:47:09
32 0 56130472 191919776 1052 2720692 470516 568080 0 0 317941 4509 1 35 65 0 0 2022-04-19 11:47:10
32 0 56224660 191906512 1052 2722080 466248 560824 0 0 316174 3856 1 35 65 0 0 2022-04-19 11:47:11
33 0 56317184 191915360 1052 2723340 470300 564260 0 0 317098 5068 1 35 65 0 0 2022-04-19 11:47:12
33 0 56417112 191917520 1052 2724656 487256 585532 0 0 321494 4297 1 35 65 0 0 2022-04-19 11:47:13
32 0 56510720 191909536 1052 2725988 476336 570728 0 0 318844 4523 1 35 65 0 0 2022-04-19 11:47:14
32 0 56606040 191907616 1052 2727160 477428 571028 0 0 318839 4175 1 35 65 0 0 2022-04-19 11:47:15
32 0 56697088 191912000 1052 2728684 466932 559020 0 0 315928 4161 1 35 65 0 0 2022-04-19 11:47:16
34 0 56787712 191907696 1052 2729860 472976 563732 0 0 316453 3950 1 35 65 0 0 2022-04-19 11:47:17
33 0 56877056 191903568 1052 2731144 468084 557924 0 0 315621 4013 1 35 65 0 0 2022-04-19 11:47:18
32 0 56965116 191896656 1052 2732380 464372 551336 0 0 314322 4152 1 35 65 0 0 2022-04-19 11:47:19
32 0 57052628 191904688 1052 2733548 477452 565748 0 0 317334 4061 1 35 65 0 0 2022-04-19 11:47:20
32 0 57142528 191914208 1052 2734816 482532 572592 0 0 318933 4272 1 35 65 0 0 2022-04-19 11:47:21
33 0 57230448 191904480 1052 2736148 479984 568060 0 0 317916 4387 1 35 65 0 0 2022-04-19 11:47:22
32 0 57318656 191904816 1052 2737416 484772 573868 0 0 319135 6673 1 35 65 0 0 2022-04-19 11:47:23
32 0 57404672 191900544 1052 2738620 489276 573784 0 0 319596 3916 1 35 65 0 0 2022-04-19 11:47:24
32 0 57489152 191899904 1052 2739888 478328 562884 0 0 317116 4208 1 35 65 0 0 2022-04-19 11:47:25
33 0 57603840 191891552 1052 2741420 640576 754120 0 0 358337 6747 0 35 65 0 0 2022-04-19 11:47:26
32 0 57713664 191896000 1052 2743184 647392 758688 0 0 359435 6227 1 35 65 0 0 2022-04-19 11:47:27
32 0 57821556 191891936 1052 2744704 635524 742832 0 0 355728 6148 1 35 65 0 0 2022-04-19 11:47:28
33 0 57925120 191897648 1052 2746600 615860 719748 0 0 350765 5732 1 35 65 0 0 2022-04-19 11:47:29
33 0 58027008 191890368 1052 2748048 615712 716600 0 0 350724 6101 1 34 65 0 0 2022-04-19 11:47:30
32 0 58126444 191885216 1052 2749596 607536 707176 0 0 348194 5085 1 35 65 0 0 2022-04-19 11:47:31
32 0 58222592 191887360 1052 2751344 600540 697816 0 0 345880 5490 1 34 65 0 0 2022-04-19 11:47:32
33 0 58320504 191886432 1052 2753188 603128 699792 0 0 346573 5464 1 34 65 0 0 2022-04-19 11:47:33
32 0 58413312 191880352 1052 2754792 598632 692808 0 0 345649 9207 1 35 65 0 0 2022-04-19 11:47:34
34 0 58507008 191891488 1052 2756788 609060 703476 0 0 347418 5584 1 35 65 0 0 2022-04-19 11:47:35
35 0 58598656 191884608 1052 2758404 595716 685588 0 0 343268 5203 1 34 65 0 0 2022-04-19 11:47:36
33 0 58687228 191881088 1052 2760176 589804 679596 0 0 341791 5229 1 34 65 0 0 2022-04-19 11:47:37
39 0 58786644 191876080 1052 2773580 585944 685572 0 0 343209 5902 1 35 64 0 0 2022-04-19 11:47:38
32 0 58871972 191867536 1052 2775512 581884 668300 0 0 339806 5101 1 34 65 0 0 2022-04-19 11:47:39
32 0 58955828 191866160 1052 2777280 566568 649184 0 0 335661 4936 1 35 65 0 0 2022-04-19 11:47:40
32 0 59040000 191869520 1052 2778848 576932 661460 0 0 338098 5150 1 34 65 0 0 2022-04-19 11:47:41
32 0 59127296 191865792 1052 2780688 595728 681228 0 0 343116 5640 1 35 65 0 0 2022-04-19 11:47:42
33 0 59240764 191861552 1052 2812080 584924 698736 0 0 346368 5982 1 36 64 0 0 2022-04-19 11:47:43
33 0 59350784 191864896 1052 2848552 557016 668704 0 0 338713 5310 1 36 64 0 0 2022-04-19 11:47:44
34 0 59467464 191864336 1052 2886880 567064 681652 0 0 342514 7503 1 36 64 0 0 2022-04-19 11:47:45
33 0 59559872 191864256 1052 2902648 576064 668796 0 0 339551 5498 1 35 65 0 0 2022-04-19 11:47:46
33 0 59654956 191859072 1052 2920248 579652 674992 0 0 341334 5458 1 35 64 0 0 2022-04-19 11:47:47
34 0 59739616 191855872 1052 2930128 573296 659060 0 0 337334 5991 1 35 64 0 0 2022-04-19 11:47:48
33 0 59836128 191860256 1052 2932236 570876 666192 0 0 339142 5845 1 35 64 0 0 2022-04-19 11:47:49
33 0 59916032 191856160 1052 2933836 549732 630988 0 0 331232 5294 1 35 64 0 0 2022-04-19 11:47:50
33 0 59984580 191864432 1052 2935316 469696 536568 0 0 310775 3927 2 35 64 0 0 2022-04-19 11:47:51
34 0 60044544 191861888 1052 2936544 459708 519548 0 0 307439 3639 2 35 64 0 0 2022-04-19 11:47:52
33 0 60100836 191855216 1052 2937860 443508 499904 0 0 302794 3567 2 35 63 0 0 2022-04-19 11:47:53
35 0 60164624 191852752 1052 2940244 474076 538824 0 0 311434 4171 2 35 63 0 0 2022-04-19 11:47:54
37 0 60217600 191897456 1052 2941936 459244 512648 0 0 305915 3861 2 34 64 0 0 2022-04-19 11:47:55
34 0 60278660 192299520 1052 2943212 475432 535428 0 0 316175 5911 1 35 64 0 0 2022-04-19 11:47:56
34 0 60298684 192311632 1052 2944424 502300 528524 0 0 311650 3770 1 35 64 0 0 2022-04-19 11:47:57
33 0 60218112 192309504 1052 2796064 586680 507856 0 0 305252 4444 1 35 64 0 0 2022-04-19 11:47:58
37 0 60278508 192305376 1052 2796960 488344 546888 0 0 315321 4236 1 35 65 0 0 2022-04-19 11:47:59
32 0 60338944 192301776 1052 2798080 489152 549504 0 0 314014 3466 1 34 65 0 0 2022-04-19 11:48:00
33 0 60397160 192300352 1052 2799292 489172 547972 0 0 313256 3819 1 35 65 0 0 2022-04-19 11:48:01
33 0 60455916 192294144 1052 2800600 489732 548700 0 0 313496 4186 1 35 65 0 0 2022-04-19 11:48:02
32 0 60513792 192298784 1052 2801780 479196 536752 0 0 310719 3561 1 35 65 0 0 2022-04-19 11:48:03
32 0 60571892 192299072 1052 2802932 494308 551784 0 0 313913 3810 1 35 65 0 0 2022-04-19 11:48:04
32 0 60628480 192295728 1052 2804116 496196 553860 0 0 314546 3935 1 35 65 0 0 2022-04-19 11:48:05
32 0 60683816 192296960 1052 2805352 486952 542444 0 0 312103 4099 1 35 65 0 0 2022-04-19 11:48:06
34 0 60739208 192291936 1052 2806660 484324 540436 0 0 311552 4432 1 35 65 0 0 2022-04-19 11:48:07
35 0 60795972 192284768 1052 2807792 492956 547732 0 0 314027 6508 1 35 65 0 0 2022-04-19 11:48:08
33 0 60847872 192290848 1052 2808992 489656 543676 0 0 312158 3829 1 34 65 0 0 2022-04-19 11:48:09
32 0 60902400 192299504 1052 2810196 486744 540604 0 0 312211 4386 1 35 65 0 0 2022-04-19 11:48:10
33 0 60955904 192293344 1052 2811400 487512 540688 0 0 312193 4135 1 35 65 0 0 2022-04-19 11:48:11
41 0 61008640 192287456 1052 2812636 484648 537540 0 0 311435 3734 1 35 65 0 0 2022-04-19 11:48:12
32 0 61061304 192289824 1052 2813872 501632 555256 0 0 314495 3876 1 35 65 0 0 2022-04-19 11:48:13
32 0 61116160 192294800 1052 2815120 497996 550700 0 0 313638 3882 1 35 65 0 0 2022-04-19 11:48:14
32 0 61167432 192284768 1052 2816368 489036 540932 0 0 311803 3839 1 35 65 0 0 2022-04-19 11:48:15
32 0 61219376 192283712 1052 2817584 491776 542744 0 0 312423 4299 1 35 65 0 0 2022-04-19 11:48:16
32 0 61272320 192295248 1052 2818656 501956 555260 0 0 315076 3976 1 35 65 0 0 2022-04-19 11:48:17
34 0 61322752 192286080 1052 2820024 488840 539240 0 0 311653 3856 1 35 65 0 0 2022-04-19 11:48:18
33 0 61372996 192282624 1052 2821132 501804 552984 0 0 314628 5787 1 34 65 0 0 2022-04-19 11:48:19
32 0 61422496 192281536 1052 2822348 479440 526896 0 0 308704 3968 1 35 65 0 0 2022-04-19 11:48:20
34 0 61468424 192270848 1052 2823436 490952 539872 0 0 311674 4014 1 35 65 0 0 2022-04-19 11:48:21
32 0 61520384 192284560 1052 2824844 498232 548180 0 0 314325 3992 1 35 65 0 0 2022-04-19 11:48:22
33 0 61567888 192276848 1052 2825996 491732 539792 0 0 312189 3861 1 35 65 0 0 2022-04-19 11:48:23
34 0 61614080 192281648 1052 2827080 497280 545980 0 0 312658 3876 1 35 65 0 0 2022-04-19 11:48:24
33 0 61663488 192279520 1052 2828252 490216 536964 0 0 311192 3803 1 35 65 0 0 2022-04-19 11:48:25
32 0 61710960 192275664 1052 2829424 489848 537324 0 0 311042 3709 1 35 65 0 0 2022-04-19 11:48:26
39 0 61757184 192268528 1052 2830676 490224 537460 0 0 311295 3764 1 35 65 0 0 2022-04-19 11:48:27
32 0 61801892 192268400 1052 2831880 489044 534368 0 0 310452 3993 1 35 65 0 0 2022-04-19 11:48:28
33 0 61850624 192271024 1052 2832980 496976 543256 0 0 312781 3875 1 35 65 0 0 2022-04-19 11:48:29
32 0 61896960 192272896 1052 2834248 500816 547220 0 0 314017 6846 1 35 65 0 0 2022-04-19 11:48:30
32 0 61942016 192264544 1052 2835416 504964 551264 0 0 314468 3845 1 35 65 0 0 2022-04-19 11:48:31
32 0 61987852 192266128 1052 2836684 491416 536948 0 0 311305 4077 1 35 65 0 0 2022-04-19 11:48:32
32 0 62030480 192261872 1052 2837900 493044 537092 0 0 311528 4065 1 35 65 0 0 2022-04-19 11:48:33
32 0 62073220 192270400 1052 2839044 487060 530204 0 0 309776 3606 1 35 65 0 0 2022-04-19 11:48:34
32 0 62118656 192271840 1052 2840276 493928 538428 0 0 311079 3850 1 35 65 0 0 2022-04-19 11:48:35
32 0 62163196 192269504 1052 2841432 490928 535392 0 0 310949 4165 1 35 65 0 0 2022-04-19 11:48:36
34 0 62209104 192267808 1052 2842632 500124 543960 0 0 313037 4160 1 35 65 0 0 2022-04-19 11:48:37
33 0 62251188 192260064 1052 2844024 511756 556448 0 0 315170 4118 1 34 65 0 0 2022-04-19 11:48:38
32 0 62295296 192257216 1052 2845320 501036 543804 0 0 312836 3961 1 35 65 0 0 2022-04-19 11:48:39
32 0 62337280 192256096 1052 2846428 492636 534648 0 0 310901 4120 1 35 65 0 0 2022-04-19 11:48:40
35 0 62381808 192254352 1052 2847612 500060 543168 0 0 312995 6369 1 35 65 0 0 2022-04-19 11:48:41
34 0 62421448 192252080 1052 2848816 495780 537168 0 0 310822 3679 1 34 65 0 0 2022-04-19 11:48:42
34 0 62464316 192254832 1052 2849936 516248 558580 0 0 316400 3753 1 35 65 0 0 2022-04-19 11:48:43
32 0 62510964 192250848 1052 2851304 579476 626888 0 0 330616 4698 1 35 65 0 0 2022-04-19 11:48:44
32 0 62557440 192247168 1052 2852712 582480 629676 0 0 331016 5219 1 34 65 0 0 2022-04-19 11:48:45
32 0 62607104 192247840 1052 2854076 595568 644328 0 0 334494 4980 1 35 65 0 0 2022-04-19 11:48:46
33 0 62653696 192252960 1052 2855384 585184 631288 0 0 331689 5091 1 35 65 0 0 2022-04-19 11:48:47
32 0 62699264 192247056 1052 2856924 589048 634808 0 0 333290 5319 1 35 65 0 0 2022-04-19 11:48:48
33 0 62742720 192245024 1052 2858264 571348 615500 0 0 328032 4545 1 34 65 0 0 2022-04-19 11:48:49
32 0 62787736 192247792 1052 2859712 577792 623332 0 0 330051 4655 1 35 65 0 0 2022-04-19 11:48:50
32 0 62832004 192245600 1052 2861044 585552 628388 0 0 331364 4666 1 34 65 0 0 2022-04-19 11:48:51
32 0 62875392 192244640 1052 2862356 565624 608764 0 0 326799 7393 1 35 65 0 0 2022-04-19 11:48:52
32 0 62917120 192238080 1052 2863796 582128 625224 0 0 330953 4872 1 35 65 0 0 2022-04-19 11:48:53
33 0 62960532 192234272 1052 2865280 590584 633648 0 0 332031 4689 1 34 65 0 0 2022-04-19 11:48:54
33 0 63004160 192235824 1052 2866680 588252 631856 0 0 331745 5039 1 35 65 0 0 2022-04-19 11:48:55
33 0 63047320 192232240 1052 2867956 586980 629588 0 0 331267 4998 1 34 65 0 0 2022-04-19 11:48:56
32 0 63087640 192245424 1052 2869348 585604 628012 0 0 330493 4927 1 35 65 0 0 2022-04-19 11:48:57
33 0 63129344 192232512 1052 2870756 574012 614840 0 0 328778 5278 1 35 65 0 0 2022-04-19 11:48:58
32 0 63171072 192237856 1052 2872228 580340 620776 0 0 329111 4859 1 34 65 0 0 2022-04-19 11:48:59
34 0 63210752 192227328 1052 2873460 578876 619924 0 0 329304 4684 1 34 65 0 0 2022-04-19 11:49:00
33 0 63251200 192220288 1052 2874784 582144 622148 0 0 329560 5017 1 34 65 0 0 2022-04-19 11:49:01
33 0 63291264 192222320 1052 2876112 580536 619900 0 0 329110 4704 1 35 65 0 0 2022-04-19 11:49:02
33 0 63328908 192219296 1052 2877620 575060 613620 0 0 327696 7029 1 35 65 0 0 2022-04-19 11:49:03
36 0 63368640 192227904 1052 2878872 589916 629468 0 0 331230 4735 1 35 65 0 0 2022-04-19 11:49:04
32 0 63407616 192226368 1052 2880100 580092 618964 0 0 329353 5036 1 35 65 0 0 2022-04-19 11:49:05
32 0 63447296 192227856 1052 2881400 573924 612468 0 0 327395 4885 1 35 65 0 0 2022-04-19 11:49:06
32 0 63483964 192220768 1052 2882800 583504 620684 0 0 329453 5140 1 35 65 0 0 2022-04-19 11:49:07
34 0 63522304 192219616 1052 2884120 570324 607480 0 0 326198 4823 1 35 65 0 0 2022-04-19 11:49:08
33 0 63558912 192211888 1052 2885476 580888 617940 0 0 328666 5086 1 34 65 0 0 2022-04-19 11:49:09
33 0 63595492 192213584 1052 2886736 584960 622084 0 0 329748 4562 1 34 65 0 0 2022-04-19 11:49:10
32 0 63632896 192210512 1052 2888120 595924 632104 0 0 331874 4517 1 35 65 0 0 2022-04-19 11:49:11
33 0 63666936 192212976 1052 2889380 577004 612232 0 0 327461 5115 1 35 65 0 0 2022-04-19 11:49:12
32 0 63701724 192218064 1052 2890824 567624 602100 0 0 325847 5177 1 35 65 0 0 2022-04-19 11:49:13
32 0 63736880 192215200 1052 2892060 584428 619836 0 0 329777 8221 1 35 65 0 0 2022-04-19 11:49:14
33 0 63770620 192215968 1052 2893280 570576 604300 0 0 326097 4686 1 35 65 0 0 2022-04-19 11:49:15
32 0 63803904 192221184 1052 2894768 568808 602056 0 0 325556 5006 1 35 65 0 0 2022-04-19 11:49:16
33 0 63833344 192212400 1052 2895944 495136 525744 0 0 309029 4239 1 35 65 0 0 2022-04-19 11:49:17
35 0 63860480 192211232 1052 2897000 507576 535204 0 0 310415 3845 1 34 65 0 0 2022-04-19 11:49:18
32 0 63892152 192207936 1052 2898188 512756 543144 0 0 312950 3642 1 35 65 0 0 2022-04-19 11:49:19
32 0 63922616 192207072 1052 2899488 510120 539604 0 0 312348 4206 1 35 65 0 0 2022-04-19 11:49:20
33 0 63950080 192208064 1052 2900680 506412 534544 0 0 310675 4162 1 35 65 0 0 2022-04-19 11:49:21
32 0 63978240 192206960 1052 2901788 508240 537108 0 0 311111 3764 1 34 65 0 0 2022-04-19 11:49:22
33 0 64005888 192204640 1052 2903032 500888 529304 0 0 310700 3802 1 35 65 0 0 2022-04-19 11:49:23
33 0 64034560 192202464 1052 2904196 512840 540380 0 0 312276 4026 1 35 65 0 0 2022-04-19 11:49:24
33 0 64062048 192201616 1052 2905220 513532 541616 0 0 312356 7302 1 35 64 0 0 2022-04-19 11:49:25
32 0 64090076 192203456 1052 2906356 518444 546404 0 0 312988 3962 1 35 65 0 0 2022-04-19 11:49:26
32 0 64120708 192204320 1052 2907596 524924 554096 0 0 314768 4291 1 35 65 0 0 2022-04-19 11:49:27
32 0 64148056 192200080 1052 2908728 498560 524804 0 0 308205 3725 1 35 65 0 0 2022-04-19 11:49:28
32 0 64174080 192194736 1052 2909892 520536 549348 0 0 313727 4293 1 35 65 0 0 2022-04-19 11:49:29
34 0 64204480 192192832 1052 2911172 516376 544820 0 0 313570 4206 1 35 65 0 0 2022-04-19 11:49:30
33 0 64230260 192203168 1052 2912248 520184 546248 0 0 313189 4025 1 34 65 0 0 2022-04-19 11:49:31
33 0 64255744 192195008 1052 2913472 507776 534924 0 0 310523 3664 1 35 65 0 0 2022-04-19 11:49:32
39 0 64282112 192193392 1052 2914516 506548 532440 0 0 310750 4296 1 35 65 0 0 2022-04-19 11:49:33
33 0 64308448 192195024 1052 2915568 506908 533216 0 0 310358 3855 1 35 65 0 0 2022-04-19 11:49:34
32 0 64334336 192196576 1052 2916784 512948 539000 0 0 312050 4143 1 35 65 0 0 2022-04-19 11:49:35
34 0 64359168 192193344 1052 2917904 502020 527060 0 0 309305 6556 1 35 65 0 0 2022-04-19 11:49:36
32 0 64386536 192196768 1052 2919116 514568 539672 0 0 312168 4291 1 35 64 0 0 2022-04-19 11:49:37
32 0 64409832 192186992 1052 2920240 506992 532228 0 0 310007 4146 1 34 65 0 0 2022-04-19 11:49:38
33 0 64435064 192191056 1052 2921456 512904 537976 0 0 311752 4276 1 35 65 0 0 2022-04-19 11:49:39
32 0 64220548 192222656 1052 2922740 615844 558524 0 0 314887 3799 1 34 65 0 0 2022-04-19 11:49:40
32 0 61157316 193033728 1052 2923724 1153000 258600 0 0 220678 2613 0 29 71 0 0 2022-04-19 11:49:41
33 0 57311092 196936640 1052 2924208 22192 0 0 0 147122 1051 0 22 78 0 0 2022-04-19 11:49:42
32 0 53440768 201176032 1052 2924228 4 0 0 0 147248 1072 0 22 78 0 0 2022-04-19 11:49:43
32 0 49573004 205453872 1052 2924244 0 0 0 0 147236 1109 0 22 78 0 0 2022-04-19 11:49:44
32 0 45707948 209583488 1052 2924264 0 0 0 0 147302 1378 0 22 78 0 0 2022-04-19 11:49:45
32 0 41845172 213813296 1052 2924284 0 0 0 0 147352 1106 0 22 78 0 0 2022-04-19 11:49:46
32 0 37993952 218130528 1052 2924304 4 0 0 0 147483 6516 0 22 78 0 0 2022-04-19 11:49:47
32 0 34145780 222392800 1052 2924344 0 0 0 0 147514 1130 0 22 78 0 0 2022-04-19 11:49:48
32 0 30304064 226625232 1052 2924344 0 0 0 0 147475 1273 0 22 78 0 0 2022-04-19 11:49:49
32 0 26478704 230731184 1052 2924368 0 0 0 0 147277 1089 0 22 78 0 0 2022-04-19 11:49:50
33 0 22660460 234876992 1052 2924408 0 0 0 0 147335 1061 0 22 78 0 0 2022-04-19 11:49:51
33 0 18857820 238900208 1052 2924408 0 0 0 0 147254 1069 0 22 78 0 0 2022-04-19 11:49:52
32 0 15092356 242988288 1052 2924428 0 0 0 0 147223 1474 0 22 78 0 0 2022-04-19 11:49:53
32 0 11356260 246985888 1052 2924448 0 0 0 0 147062 1481 0 22 78 0 0 2022-04-19 11:49:54
32 0 7660836 250787008 1052 2924472 0 0 0 0 146898 1473 0 22 78 0 0 2022-04-19 11:49:55
28 0 4077124 254481360 1052 2924516 24 0 0 0 149089 1682 0 21 79 0 0 2022-04-19 11:49:56
8 0 732064 258519760 1052 2924516 80 0 0 0 166011 2145 0 18 82 0 0 2022-04-19 11:49:57
0 0 29184 259706272 8 2535484 428 0 0 2 191790 6698 0 3 97 0 0 2022-04-19 11:49:58
0 0 18688 259724480 8 2517016 2568 0 0 0 134255 10131 0 2 98 0 0 2022-04-19 11:49:59
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-21 8:17 ` Aaron Lu
2022-04-21 8:30 ` Aaron Lu
@ 2022-04-21 8:34 ` ying.huang
2022-04-22 6:24 ` Aaron Lu
1 sibling, 1 reply; 23+ messages in thread
From: ying.huang @ 2022-04-21 8:34 UTC (permalink / raw)
To: Aaron Lu
Cc: Yang Shi, Michal Hocko, Andrew Morton, Linux MM,
Linux Kernel Mailing List
On Thu, 2022-04-21 at 16:17 +0800, Aaron Lu wrote:
> On Thu, Apr 21, 2022 at 03:49:21PM +0800, ying.huang@intel.com wrote:
> > On Wed, 2022-04-20 at 16:33 +0800, Aaron Lu wrote:
> > > On Thu, Apr 07, 2022 at 10:36:54AM -0700, Yang Shi wrote:
> > > > On Thu, Apr 7, 2022 at 1:12 AM Aaron Lu <aaron.lu@intel.com> wrote:
> > > > >
> > > > > On Wed, Apr 06, 2022 at 07:09:53PM -0700, Yang Shi wrote:
> > > > > > The swap devices are linked to per node priority lists, the swap device
> > > > > > closer to the node has higher priority on that node's priority list.
> > > > > > This is supposed to improve I/O latency, particularly for some fast
> > > > > > devices. But the current code gets nid by calling numa_node_id() which
> > > > > > actually returns the nid that the reclaimer is running on instead of the
> > > > > > nid that the page belongs to.
> > > > > >
> > > > >
> > > > > Right.
> > > > >
> > > > > > Pass the page's nid dow to get_swap_pages() in order to pick up the
> > > > > > right swap device. But it doesn't work for the swap slots cache which
> > > > > > is per cpu. We could skip swap slots cache if the current node is not
> > > > > > the page's node, but it may be overkilling. So keep using the current
> > > > > > node's swap slots cache. The issue was found by visual code inspection
> > > > > > so it is not sure how much improvement could be achieved due to lack of
> > > > > > suitable testing device. But anyway the current code does violate the
> > > > > > design.
> > > > > >
> > > > >
> > > > > I intentionally used the reclaimer's nid because I think when swapping
> > > > > out to a device, it is faster when the device is on the same node as
> > > > > the cpu.
> > > >
> > > > OK, the offline discussion with Huang Ying showed the design was to
> > > > have page's nid in order to achieve better I/O performance (more
> > > > noticeable on faster devices) since the reclaimer may be running on a
> > > > different node from the reclaimed page.
> > > >
> > > > >
> > > > > Anyway, I think I can make a test case where the workload allocates all
> > > > > its memory on the remote node and its workingset memory is larger then
> > > > > the available memory so swap is triggered, then we can see which way
> > > > > achieves better performance. Sounds reasonable to you?
> > > >
> > > > Yeah, definitely, thank you so much. I don't have a fast enough device
> > > > by hand to show the difference right now. If you could get some data
> > > > it would be perfect.
> > > >
> > >
> > > Failed to find a test box that has two NVMe disks attached to different
> > > nodes and since Shanghai is locked down right now, we couldn't install
> > > another NVMe on the box so I figured it might be OK to test on a box that
> > > has a single NVMe attached to node 0 like this:
> > >
> > > 1) restrict the test processes to run on node 0 and allocate on node 1;
> > > 2) restrict the test processes to run on node 1 and allocate on node 0.
> > >
> > > In case 1), the reclaimer's node id is the same as the swap device's so
> > > it's the same as current behaviour and in case 2), the page's node id is
> > > the same as the swap device's so it's what your patch proposed.
> > >
> > > The test I used is vm-scalability/case-swap-w-rand:
> > > https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/tree/case-swap-w-seq
> > > which spawns $nr_task processes and each will mmap $size and then
> > > randomly write to that area. I set nr_task=32 and $size=4G, so a total
> > > of 128G memory will be needed and I used memory.limit_in_bytes to
> > > restrict the available memory to 64G, to make sure swap is triggered.
> > >
> > > The reason why cgroup is used is to avoid waking up the per-node kswapd
> > > which can trigger swapping with reclaimer/page/swap device all having the
> > > same node id.
> > >
> > > And I don't see a measuable difference from the result:
> > > case1(using reclaimer's node id) vm-scalability.throughput: 10574 KB/s
> > > case2(using page's node id) vm-scalability.throughput: 10567 KB/s
> > >
> > > My interpretation of the result is, when reclaiming a remote page, it
> > > doesn't matter much which swap device to use if the swap device is a IO
> > > device.
> > >
> > > Later Ying reminded me we have test box that has optane installed on
> > > different nodes so I also tested there: Icelake 2 sockets server with 2
> > > optane installed on each node. I did the test there like this:
> > > 1) restrict the test processes to run on node 0 and allocate on node 1
> > > and only swapon pmem0, which is the optane backed swap device on node 0;
> > > 2) restrict the test processes to run on node 0 and allocate on node 1
> > > and only swapon pmem1, which is the optane backed swap device on node 1.
> > >
> > > So case 1) is current behaviour and case 2) is what your patch proposed.
> > >
> > > With the same test and the same nr_task/size, the result is:
> > > case1(using reclaimer's node id) vm-scalability.throughput: 71033 KB/s
> > > case2(using page's node id) vm-scalability.throughput: 58753 KB/s
> > >
> >
> > The per-node swap device support is more about swap-in latency than
> > swap-out throughput. I suspect the test case is more about swap-out
> > throughput. perf profiling can show this.
> >
>
> Can you elaborate the "perf profiling" part, like which perf metric can
> show this?
>
Just `perf record`, `perf report` to show where the CPU cycles are spent
with call graph information.
Then you can find most CPU cycles are for swap out or swap in. Where is
the bottleneck.
> I checked the vmstat output. Initially, it's mostly swap out, then swap
> in starts to be more and more, but swapout is always more than swapin.
>
> procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- -----timestamp-----
> r b swpd free buff cache si so bi bo in cs us sy id wa st UTC
> 20 0 0 259772032 8 2428796 0 0 2 0 365 74 1 1 98 0 0 2022-04-19 11:44:37
> 4 0 0 259149824 8 2439084 0 0 0 0 148536 22298 1 3 96 0 0 2022-04-19 11:44:38
> 35 0 0 236926192 1052 2572000 0 0 2163 2048 392940 3690 1 24 75 0 0 2022-04-19 11:44:39
> 32 0 0 205170832 1052 2572280 0 0 0 0 193095 1280 2 33 65 0 0 2022-04-19 11:44:40
> 40 0 136448 192211008 1052 2439412 268 133760 0 0 532052 3571 0 40 59 0 0 2022-04-19 11:44:43
> 33 0 4224000 192182464 1052 2450936 130636 4211460 0 0 1145644 15600 1 33 65 0 0 2022-04-19 11:44:44
> 32 0 6908708 192179408 1052 2460836 239456 2924392 0 0 863325 10731 1 34 65 0 0 2022-04-19 11:44:45
> 33 0 9005036 192163936 1052 2469112 279200 2371924 0 0 739330 9635 1 34 65 0 0 2022-04-19 11:44:46
> 32 0 10769408 192154864 1052 2476172 305516 2071440 0 0 673619 9044 1 34 65 0 0 2022-04-19 11:44:47
> 32 0 12318720 192149344 1052 2482708 324312 1875224 0 0 627868 9404 1 35 65 0 0 2022-04-19 11:44:48
> 33 0 13735796 192146752 1052 2488520 340684 1756308 0 0 601933 11815 1 35 65 0 0 2022-04-19 11:44:49
> ... ...
> 32 0 47465984 192000400 1052 2636472 456228 652756 0 0 335570 4359 0 35 65 0 0 2022-04-19 11:46:11
> 33 0 47652352 191996784 1052 2637932 437368 622652 0 0 328532 3627 1 35 65 0 0 2022-04-19 11:46:12
> 33 0 47830272 191998800 1052 2639296 428224 607516 0 0 325651 3847 1 35 65 0 0 2022-04-19 11:46:13
> 34 0 48014492 192001504 1052 2640596 441592 625308 0 0 329752 4199 1 35 65 0 0 2022-04-19 11:46:14
> 32 0 48200960 191996240 1052 2642148 458724 645744 0 0 333806 3988 0 35 65 0 0 2022-04-19 11:46:15
> 45 0 48379904 191991904 1052 2643576 442948 621268 0 0 329070 4529 0 35 65 0 0 2022-04-19 11:46:16
> 33 0 48557504 191996960 1052 2644812 444420 621948 0 0 328916 7249 1 35 64 0 0 2022-04-19 11:46:17
> 33 0 48729564 191995744 1052 2646272 447396 619376 0 0 329126 4565 0 35 65 0 0 2022-04-19 11:46:18
> 32 0 48959268 191989024 1052 2647828 595888 825480 0 0 368714 8096 0 35 65 0 0 2022-04-19 11:46:19
> 32 0 49242368 191990304 1052 2650036 746212 1028524 0 0 411140 10949 0 34 65 0 0 2022-04-19 11:46:20
> 32 0 49520792 191984080 1052 2652372 758208 1037236 0 0 415505 10094 0 34 65 0 0 2022-04-19 11:46:21
> 32 0 49799168 191994240 1052 2654724 767236 1046964 0 0 418405 10726 0 35 65 0 0 2022-04-19 11:46:22
> 32 0 50067712 191989104 1052 2657092 759192 1028600 0 0 415356 10173 0 35 65 0 0 2022-04-19 11:46:23
> 33 0 50333440 191980320 1052 2659332 750764 1014732 0 0 412144 9197 0 34 65 0 0 2022-04-19 11:46:24
> 32 0 50584052 191973824 1052 2661576 737720 988964 0 0 406620 8752 0 35 65 0 0 2022-04-19 11:46:25
> 32 0 50816000 191976080 1052 2663660 689248 921108 0 0 391782 8517 0 34 65 0 0 2022-04-19 11:46:26
> 32 0 51036416 191970464 1052 2665612 668004 888220 0 0 385112 7310 1 34 65 0 0 2022-04-19 11:46:27
> 32 0 51256576 191962224 1052 2667536 678464 897872 0 0 388494 12547 0 35 65 0 0 2022-04-19 11:46:28
> 33 0 51464680 191966304 1052 2669472 654540 862720 0 0 380869 7069 1 34 65 0 0 2022-04-19 11:46:29
> 32 0 51597232 191971840 1052 2670848 419772 552324 0 0 314325 4029 1 35 65 0 0 2022-04-19 11:46:30
> 33 0 51722448 191969456 1052 2672072 409300 535892 0 0 310720 4014 1 35 65 0 0 2022-04-19 11:46:31
> 32 0 51850496 191963472 1052 2673236 413160 541076 0 0 311652 3583 1 35 65 0 0 2022-04-19 11:46:32
> 32 0 51978872 191968208 1052 2674452 415844 543464 0 0 312411 3579 1 35 65 0 0 2022-04-19 11:46:33
> 32 0 52105724 191974640 1052 2675616 418104 545728 0 0 312731 4183 1 35 65 0 0 2022-04-19 11:46:34
> 34 0 52232928 191964336 1052 2676964 426200 552956 0 0 314230 3834 1 35 64 0 0 2022-04-19 11:46:35
>
> The full vmstat is attached.
>
> > For swap-in latency, we can use pmbench, which can output latency
> > information.
> >
>
> OK, I'll give pmbench a run, thanks for the suggestion.
Better to construct a senario with more swapin than swapout. For
example, start a memory eater, then kill it later.
Best Regards,
Huang, Ying
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-21 7:49 ` ying.huang
2022-04-21 8:17 ` Aaron Lu
@ 2022-04-21 14:11 ` Aaron Lu
2022-04-21 17:19 ` Yang Shi
2022-04-21 23:57 ` ying.huang
1 sibling, 2 replies; 23+ messages in thread
From: Aaron Lu @ 2022-04-21 14:11 UTC (permalink / raw)
To: ying.huang
Cc: Yang Shi, Michal Hocko, Andrew Morton, Linux MM,
Linux Kernel Mailing List
On Thu, Apr 21, 2022 at 03:49:21PM +0800, ying.huang@intel.com wrote:
> On Wed, 2022-04-20 at 16:33 +0800, Aaron Lu wrote:
> > On Thu, Apr 07, 2022 at 10:36:54AM -0700, Yang Shi wrote:
> > > On Thu, Apr 7, 2022 at 1:12 AM Aaron Lu <aaron.lu@intel.com> wrote:
> > > >
> > > > On Wed, Apr 06, 2022 at 07:09:53PM -0700, Yang Shi wrote:
> > > > > The swap devices are linked to per node priority lists, the swap device
> > > > > closer to the node has higher priority on that node's priority list.
> > > > > This is supposed to improve I/O latency, particularly for some fast
> > > > > devices. But the current code gets nid by calling numa_node_id() which
> > > > > actually returns the nid that the reclaimer is running on instead of the
> > > > > nid that the page belongs to.
> > > > >
> > > >
> > > > Right.
> > > >
> > > > > Pass the page's nid dow to get_swap_pages() in order to pick up the
> > > > > right swap device. But it doesn't work for the swap slots cache which
> > > > > is per cpu. We could skip swap slots cache if the current node is not
> > > > > the page's node, but it may be overkilling. So keep using the current
> > > > > node's swap slots cache. The issue was found by visual code inspection
> > > > > so it is not sure how much improvement could be achieved due to lack of
> > > > > suitable testing device. But anyway the current code does violate the
> > > > > design.
> > > > >
> > > >
> > > > I intentionally used the reclaimer's nid because I think when swapping
> > > > out to a device, it is faster when the device is on the same node as
> > > > the cpu.
> > >
> > > OK, the offline discussion with Huang Ying showed the design was to
> > > have page's nid in order to achieve better I/O performance (more
> > > noticeable on faster devices) since the reclaimer may be running on a
> > > different node from the reclaimed page.
> > >
> > > >
> > > > Anyway, I think I can make a test case where the workload allocates all
> > > > its memory on the remote node and its workingset memory is larger then
> > > > the available memory so swap is triggered, then we can see which way
> > > > achieves better performance. Sounds reasonable to you?
> > >
> > > Yeah, definitely, thank you so much. I don't have a fast enough device
> > > by hand to show the difference right now. If you could get some data
> > > it would be perfect.
> > >
> >
> > Failed to find a test box that has two NVMe disks attached to different
> > nodes and since Shanghai is locked down right now, we couldn't install
> > another NVMe on the box so I figured it might be OK to test on a box that
> > has a single NVMe attached to node 0 like this:
> >
> > 1) restrict the test processes to run on node 0 and allocate on node 1;
> > 2) restrict the test processes to run on node 1 and allocate on node 0.
> >
> > In case 1), the reclaimer's node id is the same as the swap device's so
> > it's the same as current behaviour and in case 2), the page's node id is
> > the same as the swap device's so it's what your patch proposed.
> >
> > The test I used is vm-scalability/case-swap-w-rand:
> > https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/tree/case-swap-w-seq
> > which spawns $nr_task processes and each will mmap $size and then
> > randomly write to that area. I set nr_task=32 and $size=4G, so a total
> > of 128G memory will be needed and I used memory.limit_in_bytes to
> > restrict the available memory to 64G, to make sure swap is triggered.
> >
> > The reason why cgroup is used is to avoid waking up the per-node kswapd
> > which can trigger swapping with reclaimer/page/swap device all having the
> > same node id.
> >
> > And I don't see a measuable difference from the result:
> > case1(using reclaimer's node id) vm-scalability.throughput: 10574 KB/s
> > case2(using page's node id) vm-scalability.throughput: 10567 KB/s
> >
> > My interpretation of the result is, when reclaiming a remote page, it
> > doesn't matter much which swap device to use if the swap device is a IO
> > device.
> >
> > Later Ying reminded me we have test box that has optane installed on
> > different nodes so I also tested there: Icelake 2 sockets server with 2
> > optane installed on each node. I did the test there like this:
> > 1) restrict the test processes to run on node 0 and allocate on node 1
> > and only swapon pmem0, which is the optane backed swap device on node 0;
> > 2) restrict the test processes to run on node 0 and allocate on node 1
> > and only swapon pmem1, which is the optane backed swap device on node 1.
> >
> > So case 1) is current behaviour and case 2) is what your patch proposed.
> >
> > With the same test and the same nr_task/size, the result is:
> > case1(using reclaimer's node id) vm-scalability.throughput: 71033 KB/s
> > case2(using page's node id) vm-scalability.throughput: 58753 KB/s
> >
>
> The per-node swap device support is more about swap-in latency than
> swap-out throughput. I suspect the test case is more about swap-out
> throughput. perf profiling can show this.
>
On another thought, swap out can very well affect swap in latency:
since swap is involved, the available memory is in short supply and swap
in may very likely need to reclaim a page and that reclaim can involve a
swap out, so swap out performance can also affect swap in latency.
> For swap-in latency, we can use pmbench, which can output latency
> information.
>
> Best Regards,
> Huang, Ying
>
>
> [snip]
>
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-21 14:11 ` Aaron Lu
@ 2022-04-21 17:19 ` Yang Shi
2022-04-21 23:57 ` ying.huang
1 sibling, 0 replies; 23+ messages in thread
From: Yang Shi @ 2022-04-21 17:19 UTC (permalink / raw)
To: Aaron Lu
Cc: ying.huang, Michal Hocko, Andrew Morton, Linux MM,
Linux Kernel Mailing List
On Thu, Apr 21, 2022 at 7:12 AM Aaron Lu <aaron.lu@intel.com> wrote:
>
> On Thu, Apr 21, 2022 at 03:49:21PM +0800, ying.huang@intel.com wrote:
> > On Wed, 2022-04-20 at 16:33 +0800, Aaron Lu wrote:
> > > On Thu, Apr 07, 2022 at 10:36:54AM -0700, Yang Shi wrote:
> > > > On Thu, Apr 7, 2022 at 1:12 AM Aaron Lu <aaron.lu@intel.com> wrote:
> > > > >
> > > > > On Wed, Apr 06, 2022 at 07:09:53PM -0700, Yang Shi wrote:
> > > > > > The swap devices are linked to per node priority lists, the swap device
> > > > > > closer to the node has higher priority on that node's priority list.
> > > > > > This is supposed to improve I/O latency, particularly for some fast
> > > > > > devices. But the current code gets nid by calling numa_node_id() which
> > > > > > actually returns the nid that the reclaimer is running on instead of the
> > > > > > nid that the page belongs to.
> > > > > >
> > > > >
> > > > > Right.
> > > > >
> > > > > > Pass the page's nid dow to get_swap_pages() in order to pick up the
> > > > > > right swap device. But it doesn't work for the swap slots cache which
> > > > > > is per cpu. We could skip swap slots cache if the current node is not
> > > > > > the page's node, but it may be overkilling. So keep using the current
> > > > > > node's swap slots cache. The issue was found by visual code inspection
> > > > > > so it is not sure how much improvement could be achieved due to lack of
> > > > > > suitable testing device. But anyway the current code does violate the
> > > > > > design.
> > > > > >
> > > > >
> > > > > I intentionally used the reclaimer's nid because I think when swapping
> > > > > out to a device, it is faster when the device is on the same node as
> > > > > the cpu.
> > > >
> > > > OK, the offline discussion with Huang Ying showed the design was to
> > > > have page's nid in order to achieve better I/O performance (more
> > > > noticeable on faster devices) since the reclaimer may be running on a
> > > > different node from the reclaimed page.
> > > >
> > > > >
> > > > > Anyway, I think I can make a test case where the workload allocates all
> > > > > its memory on the remote node and its workingset memory is larger then
> > > > > the available memory so swap is triggered, then we can see which way
> > > > > achieves better performance. Sounds reasonable to you?
> > > >
> > > > Yeah, definitely, thank you so much. I don't have a fast enough device
> > > > by hand to show the difference right now. If you could get some data
> > > > it would be perfect.
> > > >
> > >
> > > Failed to find a test box that has two NVMe disks attached to different
> > > nodes and since Shanghai is locked down right now, we couldn't install
> > > another NVMe on the box so I figured it might be OK to test on a box that
> > > has a single NVMe attached to node 0 like this:
> > >
> > > 1) restrict the test processes to run on node 0 and allocate on node 1;
> > > 2) restrict the test processes to run on node 1 and allocate on node 0.
> > >
> > > In case 1), the reclaimer's node id is the same as the swap device's so
> > > it's the same as current behaviour and in case 2), the page's node id is
> > > the same as the swap device's so it's what your patch proposed.
> > >
> > > The test I used is vm-scalability/case-swap-w-rand:
> > > https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/tree/case-swap-w-seq
> > > which spawns $nr_task processes and each will mmap $size and then
> > > randomly write to that area. I set nr_task=32 and $size=4G, so a total
> > > of 128G memory will be needed and I used memory.limit_in_bytes to
> > > restrict the available memory to 64G, to make sure swap is triggered.
> > >
> > > The reason why cgroup is used is to avoid waking up the per-node kswapd
> > > which can trigger swapping with reclaimer/page/swap device all having the
> > > same node id.
> > >
> > > And I don't see a measuable difference from the result:
> > > case1(using reclaimer's node id) vm-scalability.throughput: 10574 KB/s
> > > case2(using page's node id) vm-scalability.throughput: 10567 KB/s
> > >
> > > My interpretation of the result is, when reclaiming a remote page, it
> > > doesn't matter much which swap device to use if the swap device is a IO
> > > device.
> > >
> > > Later Ying reminded me we have test box that has optane installed on
> > > different nodes so I also tested there: Icelake 2 sockets server with 2
> > > optane installed on each node. I did the test there like this:
> > > 1) restrict the test processes to run on node 0 and allocate on node 1
> > > and only swapon pmem0, which is the optane backed swap device on node 0;
> > > 2) restrict the test processes to run on node 0 and allocate on node 1
> > > and only swapon pmem1, which is the optane backed swap device on node 1.
> > >
> > > So case 1) is current behaviour and case 2) is what your patch proposed.
> > >
> > > With the same test and the same nr_task/size, the result is:
> > > case1(using reclaimer's node id) vm-scalability.throughput: 71033 KB/s
> > > case2(using page's node id) vm-scalability.throughput: 58753 KB/s
> > >
> >
> > The per-node swap device support is more about swap-in latency than
> > swap-out throughput. I suspect the test case is more about swap-out
> > throughput. perf profiling can show this.
> >
>
> On another thought, swap out can very well affect swap in latency:
> since swap is involved, the available memory is in short supply and swap
> in may very likely need to reclaim a page and that reclaim can involve a
> swap out, so swap out performance can also affect swap in latency.
If you count in page allocation latency, yes. I think we could just
measure the I/O latency, for example, swap_readpage()? I'm supposed
the per-node swap device is aimed to minimize I/O latency.
>
> > For swap-in latency, we can use pmbench, which can output latency
> > information.
> >
> > Best Regards,
> > Huang, Ying
> >
> >
> > [snip]
> >
>
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-21 14:11 ` Aaron Lu
2022-04-21 17:19 ` Yang Shi
@ 2022-04-21 23:57 ` ying.huang
1 sibling, 0 replies; 23+ messages in thread
From: ying.huang @ 2022-04-21 23:57 UTC (permalink / raw)
To: Aaron Lu
Cc: Yang Shi, Michal Hocko, Andrew Morton, Linux MM,
Linux Kernel Mailing List
On Thu, 2022-04-21 at 22:11 +0800, Aaron Lu wrote:
> On Thu, Apr 21, 2022 at 03:49:21PM +0800, ying.huang@intel.com wrote:
> > On Wed, 2022-04-20 at 16:33 +0800, Aaron Lu wrote:
> > > On Thu, Apr 07, 2022 at 10:36:54AM -0700, Yang Shi wrote:
> > > > On Thu, Apr 7, 2022 at 1:12 AM Aaron Lu <aaron.lu@intel.com> wrote:
> > > > >
> > > > > On Wed, Apr 06, 2022 at 07:09:53PM -0700, Yang Shi wrote:
> > > > > > The swap devices are linked to per node priority lists, the swap device
> > > > > > closer to the node has higher priority on that node's priority list.
> > > > > > This is supposed to improve I/O latency, particularly for some fast
> > > > > > devices. But the current code gets nid by calling numa_node_id() which
> > > > > > actually returns the nid that the reclaimer is running on instead of the
> > > > > > nid that the page belongs to.
> > > > > >
> > > > >
> > > > > Right.
> > > > >
> > > > > > Pass the page's nid dow to get_swap_pages() in order to pick up the
> > > > > > right swap device. But it doesn't work for the swap slots cache which
> > > > > > is per cpu. We could skip swap slots cache if the current node is not
> > > > > > the page's node, but it may be overkilling. So keep using the current
> > > > > > node's swap slots cache. The issue was found by visual code inspection
> > > > > > so it is not sure how much improvement could be achieved due to lack of
> > > > > > suitable testing device. But anyway the current code does violate the
> > > > > > design.
> > > > > >
> > > > >
> > > > > I intentionally used the reclaimer's nid because I think when swapping
> > > > > out to a device, it is faster when the device is on the same node as
> > > > > the cpu.
> > > >
> > > > OK, the offline discussion with Huang Ying showed the design was to
> > > > have page's nid in order to achieve better I/O performance (more
> > > > noticeable on faster devices) since the reclaimer may be running on a
> > > > different node from the reclaimed page.
> > > >
> > > > >
> > > > > Anyway, I think I can make a test case where the workload allocates all
> > > > > its memory on the remote node and its workingset memory is larger then
> > > > > the available memory so swap is triggered, then we can see which way
> > > > > achieves better performance. Sounds reasonable to you?
> > > >
> > > > Yeah, definitely, thank you so much. I don't have a fast enough device
> > > > by hand to show the difference right now. If you could get some data
> > > > it would be perfect.
> > > >
> > >
> > > Failed to find a test box that has two NVMe disks attached to different
> > > nodes and since Shanghai is locked down right now, we couldn't install
> > > another NVMe on the box so I figured it might be OK to test on a box that
> > > has a single NVMe attached to node 0 like this:
> > >
> > > 1) restrict the test processes to run on node 0 and allocate on node 1;
> > > 2) restrict the test processes to run on node 1 and allocate on node 0.
> > >
> > > In case 1), the reclaimer's node id is the same as the swap device's so
> > > it's the same as current behaviour and in case 2), the page's node id is
> > > the same as the swap device's so it's what your patch proposed.
> > >
> > > The test I used is vm-scalability/case-swap-w-rand:
> > > https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/tree/case-swap-w-seq
> > > which spawns $nr_task processes and each will mmap $size and then
> > > randomly write to that area. I set nr_task=32 and $size=4G, so a total
> > > of 128G memory will be needed and I used memory.limit_in_bytes to
> > > restrict the available memory to 64G, to make sure swap is triggered.
> > >
> > > The reason why cgroup is used is to avoid waking up the per-node kswapd
> > > which can trigger swapping with reclaimer/page/swap device all having the
> > > same node id.
> > >
> > > And I don't see a measuable difference from the result:
> > > case1(using reclaimer's node id) vm-scalability.throughput: 10574 KB/s
> > > case2(using page's node id) vm-scalability.throughput: 10567 KB/s
> > >
> > > My interpretation of the result is, when reclaiming a remote page, it
> > > doesn't matter much which swap device to use if the swap device is a IO
> > > device.
> > >
> > > Later Ying reminded me we have test box that has optane installed on
> > > different nodes so I also tested there: Icelake 2 sockets server with 2
> > > optane installed on each node. I did the test there like this:
> > > 1) restrict the test processes to run on node 0 and allocate on node 1
> > > and only swapon pmem0, which is the optane backed swap device on node 0;
> > > 2) restrict the test processes to run on node 0 and allocate on node 1
> > > and only swapon pmem1, which is the optane backed swap device on node 1.
> > >
> > > So case 1) is current behaviour and case 2) is what your patch proposed.
> > >
> > > With the same test and the same nr_task/size, the result is:
> > > case1(using reclaimer's node id) vm-scalability.throughput: 71033 KB/s
> > > case2(using page's node id) vm-scalability.throughput: 58753 KB/s
> > >
> >
> > The per-node swap device support is more about swap-in latency than
> > swap-out throughput. I suspect the test case is more about swap-out
> > throughput. perf profiling can show this.
> >
>
> On another thought, swap out can very well affect swap in latency:
> since swap is involved, the available memory is in short supply and swap
> in may very likely need to reclaim a page and that reclaim can involve a
> swap out, so swap out performance can also affect swap in latency.
>
I think you are talking about thrashing. Thrashing will kill
performance. With proactive reclaiming, or something similar (e.g. kill
low priority workloads), we can introduce swapping almost without
thrashing.
I don't want to say the performance of swapout isn't important. But
swap out and swap in are different. swap out performance is more about
throughput, while swap in performance is more about latency.
Best Regards,
Huang, Ying
> > For swap-in latency, we can use pmbench, which can output latency
> > information.
> >
> > Best Regards,
> > Huang, Ying
> >
> >
> > [snip]
> >
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-21 8:34 ` ying.huang
@ 2022-04-22 6:24 ` Aaron Lu
2022-04-22 6:27 ` ying.huang
2022-04-22 17:00 ` Yang Shi
0 siblings, 2 replies; 23+ messages in thread
From: Aaron Lu @ 2022-04-22 6:24 UTC (permalink / raw)
To: ying.huang
Cc: Yang Shi, Michal Hocko, Andrew Morton, Linux MM,
Linux Kernel Mailing List
On Thu, Apr 21, 2022 at 04:34:09PM +0800, ying.huang@intel.com wrote:
> On Thu, 2022-04-21 at 16:17 +0800, Aaron Lu wrote:
> > On Thu, Apr 21, 2022 at 03:49:21PM +0800, ying.huang@intel.com wrote:
... ...
> > > For swap-in latency, we can use pmbench, which can output latency
> > > information.
> > >
> >
> > OK, I'll give pmbench a run, thanks for the suggestion.
>
> Better to construct a senario with more swapin than swapout. For
> example, start a memory eater, then kill it later.
What about vm-scalability/case-swapin?
https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/tree/case-swapin
I think you are pretty familiar with it but still:
1) it starts $nr_task processes and each mmaps $size/$nr_task area and
then consumes the memory, after this, it waits for a signal;
2) start another process to consume $size memory to push the memory in
step 1) to swap device;
3) kick processes in step 1) to start accessing their memory, thus
trigger swapins. The metric of this testcase is the swapin throughput.
I plan to restrict the cgroup's limit to $size.
Considering there is only one NVMe drive attached to node 0, I will run
the test as described before:
1) bind processes to run on node 0, allocate on node 1 to test the
performance when reclaimer's node id is the same as swap device's.
2) bind processes to run on node 1, allocate on node 0 to test the
performance when page's node id is the same as swap device's.
Ying and Yang,
Let me know what you think about the case used and the way the test is
conducted.
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-22 6:24 ` Aaron Lu
@ 2022-04-22 6:27 ` ying.huang
2022-04-22 6:43 ` Aaron Lu
2022-04-22 17:00 ` Yang Shi
1 sibling, 1 reply; 23+ messages in thread
From: ying.huang @ 2022-04-22 6:27 UTC (permalink / raw)
To: Aaron Lu
Cc: Yang Shi, Michal Hocko, Andrew Morton, Linux MM,
Linux Kernel Mailing List
On Fri, 2022-04-22 at 14:24 +0800, Aaron Lu wrote:
> On Thu, Apr 21, 2022 at 04:34:09PM +0800, ying.huang@intel.com wrote:
> > On Thu, 2022-04-21 at 16:17 +0800, Aaron Lu wrote:
> > > On Thu, Apr 21, 2022 at 03:49:21PM +0800, ying.huang@intel.com wrote:
>
> ... ...
>
> > > > For swap-in latency, we can use pmbench, which can output latency
> > > > information.
> > > >
> > >
> > > OK, I'll give pmbench a run, thanks for the suggestion.
> >
> > Better to construct a senario with more swapin than swapout. For
> > example, start a memory eater, then kill it later.
>
> What about vm-scalability/case-swapin?
> https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/tree/case-swapin
>
> I think you are pretty familiar with it but still:
> 1) it starts $nr_task processes and each mmaps $size/$nr_task area and
> then consumes the memory, after this, it waits for a signal;
> 2) start another process to consume $size memory to push the memory in
> step 1) to swap device;
> 3) kick processes in step 1) to start accessing their memory, thus
> trigger swapins. The metric of this testcase is the swapin throughput.
>
> I plan to restrict the cgroup's limit to $size.
>
> Considering there is only one NVMe drive attached to node 0, I will run
> the test as described before:
> 1) bind processes to run on node 0, allocate on node 1 to test the
> performance when reclaimer's node id is the same as swap device's.
> 2) bind processes to run on node 1, allocate on node 0 to test the
> performance when page's node id is the same as swap device's.
>
> Ying and Yang,
>
> Let me know what you think about the case used and the way the test is
> conducted.
The test case looks good to me. And, do you have a way to measure swap
in latency? Better to compare between enabling and disabling per-node
swap device support too to make sure per-node support has performance
impact on this system.
Best Regards,
Huang, Ying
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-22 6:27 ` ying.huang
@ 2022-04-22 6:43 ` Aaron Lu
2022-04-22 7:26 ` ying.huang
0 siblings, 1 reply; 23+ messages in thread
From: Aaron Lu @ 2022-04-22 6:43 UTC (permalink / raw)
To: ying.huang
Cc: Yang Shi, Michal Hocko, Andrew Morton, Linux MM,
Linux Kernel Mailing List
On Fri, Apr 22, 2022 at 02:27:45PM +0800, ying.huang@intel.com wrote:
> On Fri, 2022-04-22 at 14:24 +0800, Aaron Lu wrote:
> > On Thu, Apr 21, 2022 at 04:34:09PM +0800, ying.huang@intel.com wrote:
> > > On Thu, 2022-04-21 at 16:17 +0800, Aaron Lu wrote:
> > > > On Thu, Apr 21, 2022 at 03:49:21PM +0800, ying.huang@intel.com wrote:
> >
> > ... ...
> >
> > > > > For swap-in latency, we can use pmbench, which can output latency
> > > > > information.
> > > > >
> > > >
> > > > OK, I'll give pmbench a run, thanks for the suggestion.
> > >
> > > Better to construct a senario with more swapin than swapout. For
> > > example, start a memory eater, then kill it later.
> >
> > What about vm-scalability/case-swapin?
> > https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/tree/case-swapin
> >
> > I think you are pretty familiar with it but still:
> > 1) it starts $nr_task processes and each mmaps $size/$nr_task area and
> > then consumes the memory, after this, it waits for a signal;
> > 2) start another process to consume $size memory to push the memory in
> > step 1) to swap device;
> > 3) kick processes in step 1) to start accessing their memory, thus
> > trigger swapins. The metric of this testcase is the swapin throughput.
> >
> > I plan to restrict the cgroup's limit to $size.
> >
> > Considering there is only one NVMe drive attached to node 0, I will run
> > the test as described before:
> > 1) bind processes to run on node 0, allocate on node 1 to test the
> > performance when reclaimer's node id is the same as swap device's.
> > 2) bind processes to run on node 1, allocate on node 0 to test the
> > performance when page's node id is the same as swap device's.
> >
> > Ying and Yang,
> >
> > Let me know what you think about the case used and the way the test is
> > conducted.
>
> The test case looks good to me. And, do you have a way to measure swap
> in latency? Better to compare between enabling and disabling per-node
By swap in latency, do you mean the time it takes for a fault that is
served by swap in?
Since the test is swap in only, I think throughput can tell us the
average swap in latency?
> swap device support too to make sure per-node support has performance
> impact on this system.
I think we can tell by conducting two more tests:
1) bind processes to run on node 0, allocate on node 0;
2) bind processes to run on node 1, allocate on node 1.
If case 1) is faster, we can say per-node support has performance impact
on this system.
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-22 6:43 ` Aaron Lu
@ 2022-04-22 7:26 ` ying.huang
0 siblings, 0 replies; 23+ messages in thread
From: ying.huang @ 2022-04-22 7:26 UTC (permalink / raw)
To: Aaron Lu
Cc: Yang Shi, Michal Hocko, Andrew Morton, Linux MM,
Linux Kernel Mailing List
On Fri, 2022-04-22 at 14:43 +0800, Aaron Lu wrote:
> On Fri, Apr 22, 2022 at 02:27:45PM +0800, ying.huang@intel.com wrote:
> > On Fri, 2022-04-22 at 14:24 +0800, Aaron Lu wrote:
> > > On Thu, Apr 21, 2022 at 04:34:09PM +0800, ying.huang@intel.com wrote:
> > > > On Thu, 2022-04-21 at 16:17 +0800, Aaron Lu wrote:
> > > > > On Thu, Apr 21, 2022 at 03:49:21PM +0800, ying.huang@intel.com wrote:
> > >
> > > ... ...
> > >
> > > > > > For swap-in latency, we can use pmbench, which can output latency
> > > > > > information.
> > > > > >
> > > > >
> > > > > OK, I'll give pmbench a run, thanks for the suggestion.
> > > >
> > > > Better to construct a senario with more swapin than swapout. For
> > > > example, start a memory eater, then kill it later.
> > >
> > > What about vm-scalability/case-swapin?
> > > https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/tree/case-swapin
> > >
> > > I think you are pretty familiar with it but still:
> > > 1) it starts $nr_task processes and each mmaps $size/$nr_task area and
> > > then consumes the memory, after this, it waits for a signal;
> > > 2) start another process to consume $size memory to push the memory in
> > > step 1) to swap device;
> > > 3) kick processes in step 1) to start accessing their memory, thus
> > > trigger swapins. The metric of this testcase is the swapin throughput.
> > >
> > > I plan to restrict the cgroup's limit to $size.
> > >
> > > Considering there is only one NVMe drive attached to node 0, I will run
> > > the test as described before:
> > > 1) bind processes to run on node 0, allocate on node 1 to test the
> > > performance when reclaimer's node id is the same as swap device's.
> > > 2) bind processes to run on node 1, allocate on node 0 to test the
> > > performance when page's node id is the same as swap device's.
> > >
> > > Ying and Yang,
> > >
> > > Let me know what you think about the case used and the way the test is
> > > conducted.
> >
> > The test case looks good to me. And, do you have a way to measure swap
> > in latency? Better to compare between enabling and disabling per-node
>
> By swap in latency, do you mean the time it takes for a fault that is
> served by swap in?
>
> Since the test is swap in only, I think throughput can tell us the
> average swap in latency?
>
Yes. Given the same parallel level, the average swap in latency can be
reflect via throughput.
> > swap device support too to make sure per-node support has performance
> > impact on this system.
>
> I think we can tell by conducting two more tests:
> 1) bind processes to run on node 0, allocate on node 0;
> 2) bind processes to run on node 1, allocate on node 1.
> If case 1) is faster, we can say per-node support has performance impact
> on this system.
At least we can measure whether cross-node latency matters with this
test.
Best Regards,
Huang, Ying
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-22 6:24 ` Aaron Lu
2022-04-22 6:27 ` ying.huang
@ 2022-04-22 17:00 ` Yang Shi
2022-04-23 3:22 ` Aaron Lu
2022-04-29 10:26 ` Aaron Lu
1 sibling, 2 replies; 23+ messages in thread
From: Yang Shi @ 2022-04-22 17:00 UTC (permalink / raw)
To: Aaron Lu
Cc: ying.huang, Michal Hocko, Andrew Morton, Linux MM,
Linux Kernel Mailing List
On Thu, Apr 21, 2022 at 11:24 PM Aaron Lu <aaron.lu@intel.com> wrote:
>
> On Thu, Apr 21, 2022 at 04:34:09PM +0800, ying.huang@intel.com wrote:
> > On Thu, 2022-04-21 at 16:17 +0800, Aaron Lu wrote:
> > > On Thu, Apr 21, 2022 at 03:49:21PM +0800, ying.huang@intel.com wrote:
>
> ... ...
>
> > > > For swap-in latency, we can use pmbench, which can output latency
> > > > information.
> > > >
> > >
> > > OK, I'll give pmbench a run, thanks for the suggestion.
> >
> > Better to construct a senario with more swapin than swapout. For
> > example, start a memory eater, then kill it later.
>
> What about vm-scalability/case-swapin?
> https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/tree/case-swapin
>
> I think you are pretty familiar with it but still:
> 1) it starts $nr_task processes and each mmaps $size/$nr_task area and
> then consumes the memory, after this, it waits for a signal;
> 2) start another process to consume $size memory to push the memory in
> step 1) to swap device;
> 3) kick processes in step 1) to start accessing their memory, thus
> trigger swapins. The metric of this testcase is the swapin throughput.
>
> I plan to restrict the cgroup's limit to $size.
>
> Considering there is only one NVMe drive attached to node 0, I will run
> the test as described before:
> 1) bind processes to run on node 0, allocate on node 1 to test the
> performance when reclaimer's node id is the same as swap device's.
> 2) bind processes to run on node 1, allocate on node 0 to test the
> performance when page's node id is the same as swap device's.
>
> Ying and Yang,
>
> Let me know what you think about the case used and the way the test is
> conducted.
Looks fine to me. To measure the latency, you could also try the below
bpftrace script:
#! /usr/bin/bpftrace
kprobe:swap_readpage
{
@start[tid] = nsecs;
}
kretprobe:swap_readpage
/@start[tid]/
{
@us[comm] = hist((nsecs - @start[tid]) / 1000);
delete(@start[tid]);
}
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-22 17:00 ` Yang Shi
@ 2022-04-23 3:22 ` Aaron Lu
2022-04-29 10:26 ` Aaron Lu
1 sibling, 0 replies; 23+ messages in thread
From: Aaron Lu @ 2022-04-23 3:22 UTC (permalink / raw)
To: Yang Shi
Cc: ying.huang, Michal Hocko, Andrew Morton, Linux MM,
Linux Kernel Mailing List
On Fri, Apr 22, 2022 at 10:00:59AM -0700, Yang Shi wrote:
> On Thu, Apr 21, 2022 at 11:24 PM Aaron Lu <aaron.lu@intel.com> wrote:
> >
> > On Thu, Apr 21, 2022 at 04:34:09PM +0800, ying.huang@intel.com wrote:
> > > On Thu, 2022-04-21 at 16:17 +0800, Aaron Lu wrote:
> > > > On Thu, Apr 21, 2022 at 03:49:21PM +0800, ying.huang@intel.com wrote:
> >
> > ... ...
> >
> > > > > For swap-in latency, we can use pmbench, which can output latency
> > > > > information.
> > > > >
> > > >
> > > > OK, I'll give pmbench a run, thanks for the suggestion.
> > >
> > > Better to construct a senario with more swapin than swapout. For
> > > example, start a memory eater, then kill it later.
> >
> > What about vm-scalability/case-swapin?
> > https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/tree/case-swapin
> >
> > I think you are pretty familiar with it but still:
> > 1) it starts $nr_task processes and each mmaps $size/$nr_task area and
> > then consumes the memory, after this, it waits for a signal;
> > 2) start another process to consume $size memory to push the memory in
> > step 1) to swap device;
> > 3) kick processes in step 1) to start accessing their memory, thus
> > trigger swapins. The metric of this testcase is the swapin throughput.
> >
> > I plan to restrict the cgroup's limit to $size.
> >
> > Considering there is only one NVMe drive attached to node 0, I will run
> > the test as described before:
> > 1) bind processes to run on node 0, allocate on node 1 to test the
> > performance when reclaimer's node id is the same as swap device's.
> > 2) bind processes to run on node 1, allocate on node 0 to test the
> > performance when page's node id is the same as swap device's.
> >
> > Ying and Yang,
> >
> > Let me know what you think about the case used and the way the test is
> > conducted.
>
> Looks fine to me. To measure the latency, you could also try the below
> bpftrace script:
Yeah, bpftrace can nicely show us the histogram of the latency.
The hard part is to integrate bpftrace into LKP framework though.
>
> #! /usr/bin/bpftrace
>
> kprobe:swap_readpage
> {
> @start[tid] = nsecs;
> }
>
> kretprobe:swap_readpage
> /@start[tid]/
> {
> @us[comm] = hist((nsecs - @start[tid]) / 1000);
> delete(@start[tid]);
> }
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-22 17:00 ` Yang Shi
2022-04-23 3:22 ` Aaron Lu
@ 2022-04-29 10:26 ` Aaron Lu
2022-04-29 19:07 ` Yang Shi
1 sibling, 1 reply; 23+ messages in thread
From: Aaron Lu @ 2022-04-29 10:26 UTC (permalink / raw)
To: Yang Shi
Cc: ying.huang, Michal Hocko, Andrew Morton, Linux MM,
Linux Kernel Mailing List, Tim Chen
On Fri, Apr 22, 2022 at 10:00:59AM -0700, Yang Shi wrote:
> On Thu, Apr 21, 2022 at 11:24 PM Aaron Lu <aaron.lu@intel.com> wrote:
> >
> > On Thu, Apr 21, 2022 at 04:34:09PM +0800, ying.huang@intel.com wrote:
> > > On Thu, 2022-04-21 at 16:17 +0800, Aaron Lu wrote:
> > > > On Thu, Apr 21, 2022 at 03:49:21PM +0800, ying.huang@intel.com wrote:
> >
> > ... ...
> >
> > > > > For swap-in latency, we can use pmbench, which can output latency
> > > > > information.
> > > > >
> > > >
> > > > OK, I'll give pmbench a run, thanks for the suggestion.
> > >
> > > Better to construct a senario with more swapin than swapout. For
> > > example, start a memory eater, then kill it later.
> >
> > What about vm-scalability/case-swapin?
> > https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/tree/case-swapin
> >
> > I think you are pretty familiar with it but still:
> > 1) it starts $nr_task processes and each mmaps $size/$nr_task area and
> > then consumes the memory, after this, it waits for a signal;
> > 2) start another process to consume $size memory to push the memory in
> > step 1) to swap device;
> > 3) kick processes in step 1) to start accessing their memory, thus
> > trigger swapins. The metric of this testcase is the swapin throughput.
> >
> > I plan to restrict the cgroup's limit to $size.
> >
> > Considering there is only one NVMe drive attached to node 0, I will run
> > the test as described before:
> > 1) bind processes to run on node 0, allocate on node 1 to test the
> > performance when reclaimer's node id is the same as swap device's.
> > 2) bind processes to run on node 1, allocate on node 0 to test the
> > performance when page's node id is the same as swap device's.
> >
Thanks to Tim, he has found me a server that has a single Optane disk
attached to node 0.
Let's use task0_mem0 to denote tasks bound to node 0 and memory bound
to node 0 through cgroup cpuset. And for the above swapin case:
when nr_task=1:
task0_mem0 throughput: [571652, 587158, 594316], avg=584375 -> baseline
task0_mem1 throughput: [582944, 583752, 589026], avg=585240 +0.15%
task1_mem0 throughput: [569349, 577459, 581107], avg=575971 -1.4%
task1_mem1 throughput: [564482, 570664, 571466], avg=568870 -2.6%
task0_mem1 is slightly better than task1_mem0.
For nr_task=8 or nr_task=16, I also gave it a run and the result is
almost the same for all 4 cases.
> > Ying and Yang,
> >
> > Let me know what you think about the case used and the way the test is
> > conducted.
>
> Looks fine to me. To measure the latency, you could also try the below
> bpftrace script:
>
Trying to install bpftrace on an old distro(Ubuntu 16.04) is a real
pain, I gave up... But I managed to get an old bcc installed. Using
the provided funclatency script to profile 30 seconds swap_readpage(),
there is no obvious difference from the histrogram.
So for now, from the existing results, it did't show big difference.
Theoretically, for IO device, when swapping a remote page, using the
remote swap device that is at the same node as the page can reduce the
traffic of the interlink and improve performance. I think this is the
main motivation for this code change?
On swapin time, it's hard to say which node the task will run on anyway
so it's hard to say where to swap is beneficial.
^ permalink raw reply [flat|nested] 23+ messages in thread
* Re: [PATCH] mm: swap: determine swap device by using page nid
2022-04-29 10:26 ` Aaron Lu
@ 2022-04-29 19:07 ` Yang Shi
0 siblings, 0 replies; 23+ messages in thread
From: Yang Shi @ 2022-04-29 19:07 UTC (permalink / raw)
To: Aaron Lu
Cc: ying.huang, Michal Hocko, Andrew Morton, Linux MM,
Linux Kernel Mailing List, Tim Chen
On Fri, Apr 29, 2022 at 3:27 AM Aaron Lu <aaron.lu@intel.com> wrote:
>
> On Fri, Apr 22, 2022 at 10:00:59AM -0700, Yang Shi wrote:
> > On Thu, Apr 21, 2022 at 11:24 PM Aaron Lu <aaron.lu@intel.com> wrote:
> > >
> > > On Thu, Apr 21, 2022 at 04:34:09PM +0800, ying.huang@intel.com wrote:
> > > > On Thu, 2022-04-21 at 16:17 +0800, Aaron Lu wrote:
> > > > > On Thu, Apr 21, 2022 at 03:49:21PM +0800, ying.huang@intel.com wrote:
> > >
> > > ... ...
> > >
> > > > > > For swap-in latency, we can use pmbench, which can output latency
> > > > > > information.
> > > > > >
> > > > >
> > > > > OK, I'll give pmbench a run, thanks for the suggestion.
> > > >
> > > > Better to construct a senario with more swapin than swapout. For
> > > > example, start a memory eater, then kill it later.
> > >
> > > What about vm-scalability/case-swapin?
> > > https://git.kernel.org/pub/scm/linux/kernel/git/wfg/vm-scalability.git/tree/case-swapin
> > >
> > > I think you are pretty familiar with it but still:
> > > 1) it starts $nr_task processes and each mmaps $size/$nr_task area and
> > > then consumes the memory, after this, it waits for a signal;
> > > 2) start another process to consume $size memory to push the memory in
> > > step 1) to swap device;
> > > 3) kick processes in step 1) to start accessing their memory, thus
> > > trigger swapins. The metric of this testcase is the swapin throughput.
> > >
> > > I plan to restrict the cgroup's limit to $size.
> > >
> > > Considering there is only one NVMe drive attached to node 0, I will run
> > > the test as described before:
> > > 1) bind processes to run on node 0, allocate on node 1 to test the
> > > performance when reclaimer's node id is the same as swap device's.
> > > 2) bind processes to run on node 1, allocate on node 0 to test the
> > > performance when page's node id is the same as swap device's.
> > >
>
> Thanks to Tim, he has found me a server that has a single Optane disk
> attached to node 0.
>
> Let's use task0_mem0 to denote tasks bound to node 0 and memory bound
> to node 0 through cgroup cpuset. And for the above swapin case:
> when nr_task=1:
> task0_mem0 throughput: [571652, 587158, 594316], avg=584375 -> baseline
> task0_mem1 throughput: [582944, 583752, 589026], avg=585240 +0.15%
> task1_mem0 throughput: [569349, 577459, 581107], avg=575971 -1.4%
> task1_mem1 throughput: [564482, 570664, 571466], avg=568870 -2.6%
>
> task0_mem1 is slightly better than task1_mem0.
>
> For nr_task=8 or nr_task=16, I also gave it a run and the result is
> almost the same for all 4 cases.
>
> > > Ying and Yang,
> > >
> > > Let me know what you think about the case used and the way the test is
> > > conducted.
> >
> > Looks fine to me. To measure the latency, you could also try the below
> > bpftrace script:
> >
>
> Trying to install bpftrace on an old distro(Ubuntu 16.04) is a real
> pain, I gave up... But I managed to get an old bcc installed. Using
> the provided funclatency script to profile 30 seconds swap_readpage(),
> there is no obvious difference from the histrogram.
Thank you so much for the testing.
>
> So for now, from the existing results, it did't show big difference.
> Theoretically, for IO device, when swapping a remote page, using the
> remote swap device that is at the same node as the page can reduce the
> traffic of the interlink and improve performance. I think this is the
> main motivation for this code change?
Yes.
Given the result it seems better to keep the code as-is.
> On swapin time, it's hard to say which node the task will run on anyway
> so it's hard to say where to swap is beneficial.
>
^ permalink raw reply [flat|nested] 23+ messages in thread
end of thread, other threads:[~2022-04-29 19:07 UTC | newest]
Thread overview: 23+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2022-04-07 2:09 [PATCH] mm: swap: determine swap device by using page nid Yang Shi
2022-04-07 7:52 ` Michal Hocko
2022-04-07 17:27 ` Yang Shi
2022-04-07 8:13 ` Aaron Lu
2022-04-07 17:36 ` Yang Shi
2022-04-20 8:33 ` Aaron Lu
2022-04-20 22:21 ` Yang Shi
2022-04-21 7:34 ` Aaron Lu
2022-04-21 7:49 ` ying.huang
2022-04-21 8:17 ` Aaron Lu
2022-04-21 8:30 ` Aaron Lu
2022-04-21 8:34 ` ying.huang
2022-04-22 6:24 ` Aaron Lu
2022-04-22 6:27 ` ying.huang
2022-04-22 6:43 ` Aaron Lu
2022-04-22 7:26 ` ying.huang
2022-04-22 17:00 ` Yang Shi
2022-04-23 3:22 ` Aaron Lu
2022-04-29 10:26 ` Aaron Lu
2022-04-29 19:07 ` Yang Shi
2022-04-21 14:11 ` Aaron Lu
2022-04-21 17:19 ` Yang Shi
2022-04-21 23:57 ` ying.huang
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.