* [PATCH] mm: check nr_initialised with PAGES_PER_SECTION directly in defer_init()
@ 2018-11-22 9:48 Wei Yang
2018-12-20 23:01 ` Andrew Morton
2018-12-20 23:50 ` Alexander Duyck
0 siblings, 2 replies; 4+ messages in thread
From: Wei Yang @ 2018-11-22 9:48 UTC (permalink / raw)
To: osalvador; +Cc: akpm, linux-mm, Wei Yang
When DEFERRED_STRUCT_PAGE_INIT is configured, only the first section of
each node's highest zone is initialized before defer stage.
static_init_pgcnt is used to store the number of pages like this:
pgdat->static_init_pgcnt = min_t(unsigned long, PAGES_PER_SECTION,
pgdat->node_spanned_pages);
because we don't want to overflow zone's range.
But this is not necessary, since defer_init() is called like this:
memmap_init_zone()
for pfn in [start_pfn, end_pfn)
defer_init(pfn, end_pfn)
In case (pgdat->node_spanned_pages < PAGES_PER_SECTION), the loop would
stop before calling defer_init().
BTW, comparing PAGES_PER_SECTION with node_spanned_pages is not correct,
since nr_initialised is zone based instead of node based. Even
node_spanned_pages is bigger than PAGES_PER_SECTION, its highest zone
would have pages less than PAGES_PER_SECTION.
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
---
include/linux/mmzone.h | 2 --
mm/page_alloc.c | 13 ++++++-------
2 files changed, 6 insertions(+), 9 deletions(-)
diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
index ae7a830a21eb..68d7b558924b 100644
--- a/include/linux/mmzone.h
+++ b/include/linux/mmzone.h
@@ -692,8 +692,6 @@ typedef struct pglist_data {
* is the first PFN that needs to be initialised.
*/
unsigned long first_deferred_pfn;
- /* Number of non-deferred pages */
- unsigned long static_init_pgcnt;
#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 76e12179cd5e..b542d82400cf 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -326,8 +326,13 @@ defer_init(int nid, unsigned long pfn, unsigned long end_pfn)
/* Always populate low zones for address-constrained allocations */
if (end_pfn < pgdat_end_pfn(NODE_DATA(nid)))
return false;
+
+ /*
+ * We start only with one section of pages, more pages are added as
+ * needed until the rest of deferred pages are initialized.
+ */
nr_initialised++;
- if ((nr_initialised > NODE_DATA(nid)->static_init_pgcnt) &&
+ if ((nr_initialised > PAGES_PER_SECTION) &&
(pfn & (PAGES_PER_SECTION - 1)) == 0) {
NODE_DATA(nid)->first_deferred_pfn = pfn;
return true;
@@ -6451,12 +6456,6 @@ static void __ref alloc_node_mem_map(struct pglist_data *pgdat) { }
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
static inline void pgdat_set_deferred_range(pg_data_t *pgdat)
{
- /*
- * We start only with one section of pages, more pages are added as
- * needed until the rest of deferred pages are initialized.
- */
- pgdat->static_init_pgcnt = min_t(unsigned long, PAGES_PER_SECTION,
- pgdat->node_spanned_pages);
pgdat->first_deferred_pfn = ULONG_MAX;
}
#else
--
2.15.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH] mm: check nr_initialised with PAGES_PER_SECTION directly in defer_init()
2018-11-22 9:48 [PATCH] mm: check nr_initialised with PAGES_PER_SECTION directly in defer_init() Wei Yang
@ 2018-12-20 23:01 ` Andrew Morton
2018-12-20 23:50 ` Alexander Duyck
1 sibling, 0 replies; 4+ messages in thread
From: Andrew Morton @ 2018-12-20 23:01 UTC (permalink / raw)
To: Wei Yang; +Cc: osalvador, linux-mm
Could someone please review this?
From: Wei Yang <richard.weiyang@gmail.com>
Subject: mm: check nr_initialised with PAGES_PER_SECTION directly in defer_init()
When DEFERRED_STRUCT_PAGE_INIT is configured, only the first section of
each node's highest zone is initialized before defer stage.
static_init_pgcnt is used to store the number of pages like this:
pgdat->static_init_pgcnt = min_t(unsigned long, PAGES_PER_SECTION,
pgdat->node_spanned_pages);
because we don't want to overflow zone's range.
But this is not necessary, since defer_init() is called like this:
memmap_init_zone()
for pfn in [start_pfn, end_pfn)
defer_init(pfn, end_pfn)
In case (pgdat->node_spanned_pages < PAGES_PER_SECTION), the loop would
stop before calling defer_init().
BTW, comparing PAGES_PER_SECTION with node_spanned_pages is not correct,
since nr_initialised is zone based instead of node based. Even
node_spanned_pages is bigger than PAGES_PER_SECTION, its highest zone
would have pages less than PAGES_PER_SECTION.
Link: http://lkml.kernel.org/r/20181122094807.6985-1-richard.weiyang@gmail.com
Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
Cc: Pavel Tatashin <pasha.tatashin@oracle.com>
Cc: Oscar Salvador <osalvador@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---
include/linux/mmzone.h | 2 --
mm/page_alloc.c | 13 ++++++-------
2 files changed, 6 insertions(+), 9 deletions(-)
--- a/include/linux/mmzone.h~mm-check-nr_initialised-with-pages_per_section-directly-in-defer_init
+++ a/include/linux/mmzone.h
@@ -692,8 +692,6 @@ typedef struct pglist_data {
* is the first PFN that needs to be initialised.
*/
unsigned long first_deferred_pfn;
- /* Number of non-deferred pages */
- unsigned long static_init_pgcnt;
#endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
#ifdef CONFIG_TRANSPARENT_HUGEPAGE
--- a/mm/page_alloc.c~mm-check-nr_initialised-with-pages_per_section-directly-in-defer_init
+++ a/mm/page_alloc.c
@@ -326,8 +326,13 @@ defer_init(int nid, unsigned long pfn, u
/* Always populate low zones for address-constrained allocations */
if (end_pfn < pgdat_end_pfn(NODE_DATA(nid)))
return false;
+
+ /*
+ * We start only with one section of pages, more pages are added as
+ * needed until the rest of deferred pages are initialized.
+ */
nr_initialised++;
- if ((nr_initialised > NODE_DATA(nid)->static_init_pgcnt) &&
+ if ((nr_initialised > PAGES_PER_SECTION) &&
(pfn & (PAGES_PER_SECTION - 1)) == 0) {
NODE_DATA(nid)->first_deferred_pfn = pfn;
return true;
@@ -6585,12 +6590,6 @@ static void __ref alloc_node_mem_map(str
#ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
static inline void pgdat_set_deferred_range(pg_data_t *pgdat)
{
- /*
- * We start only with one section of pages, more pages are added as
- * needed until the rest of deferred pages are initialized.
- */
- pgdat->static_init_pgcnt = min_t(unsigned long, PAGES_PER_SECTION,
- pgdat->node_spanned_pages);
pgdat->first_deferred_pfn = ULONG_MAX;
}
#else
_
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mm: check nr_initialised with PAGES_PER_SECTION directly in defer_init()
2018-11-22 9:48 [PATCH] mm: check nr_initialised with PAGES_PER_SECTION directly in defer_init() Wei Yang
2018-12-20 23:01 ` Andrew Morton
@ 2018-12-20 23:50 ` Alexander Duyck
2018-12-21 3:39 ` Wei Yang
1 sibling, 1 reply; 4+ messages in thread
From: Alexander Duyck @ 2018-12-20 23:50 UTC (permalink / raw)
To: Wei Yang, osalvador; +Cc: akpm, linux-mm
On Thu, 2018-11-22 at 17:48 +0800, Wei Yang wrote:
> When DEFERRED_STRUCT_PAGE_INIT is configured, only the first section of
> each node's highest zone is initialized before defer stage.
>
> static_init_pgcnt is used to store the number of pages like this:
>
> pgdat->static_init_pgcnt = min_t(unsigned long, PAGES_PER_SECTION,
> pgdat->node_spanned_pages);
>
> because we don't want to overflow zone's range.
>
> But this is not necessary, since defer_init() is called like this:
>
> memmap_init_zone()
> for pfn in [start_pfn, end_pfn)
> defer_init(pfn, end_pfn)
>
> In case (pgdat->node_spanned_pages < PAGES_PER_SECTION), the loop would
> stop before calling defer_init().
>
> BTW, comparing PAGES_PER_SECTION with node_spanned_pages is not correct,
> since nr_initialised is zone based instead of node based. Even
> node_spanned_pages is bigger than PAGES_PER_SECTION, its highest zone
> would have pages less than PAGES_PER_SECTION.
>
> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
This all seems to make sense to me, and appears to be a valid
improvement.
Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
> ---
> include/linux/mmzone.h | 2 --
> mm/page_alloc.c | 13 ++++++-------
> 2 files changed, 6 insertions(+), 9 deletions(-)
>
> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
> index ae7a830a21eb..68d7b558924b 100644
> --- a/include/linux/mmzone.h
> +++ b/include/linux/mmzone.h
> @@ -692,8 +692,6 @@ typedef struct pglist_data {
> * is the first PFN that needs to be initialised.
> */
> unsigned long first_deferred_pfn;
> - /* Number of non-deferred pages */
> - unsigned long static_init_pgcnt;
> #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
>
> #ifdef CONFIG_TRANSPARENT_HUGEPAGE
> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
> index 76e12179cd5e..b542d82400cf 100644
> --- a/mm/page_alloc.c
> +++ b/mm/page_alloc.c
> @@ -326,8 +326,13 @@ defer_init(int nid, unsigned long pfn, unsigned long end_pfn)
> /* Always populate low zones for address-constrained allocations */
> if (end_pfn < pgdat_end_pfn(NODE_DATA(nid)))
> return false;
> +
> + /*
> + * We start only with one section of pages, more pages are added as
> + * needed until the rest of deferred pages are initialized.
> + */
> nr_initialised++;
> - if ((nr_initialised > NODE_DATA(nid)->static_init_pgcnt) &&
> + if ((nr_initialised > PAGES_PER_SECTION) &&
> (pfn & (PAGES_PER_SECTION - 1)) == 0) {
> NODE_DATA(nid)->first_deferred_pfn = pfn;
> return true;
> @@ -6451,12 +6456,6 @@ static void __ref alloc_node_mem_map(struct pglist_data *pgdat) { }
> #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
> static inline void pgdat_set_deferred_range(pg_data_t *pgdat)
> {
> - /*
> - * We start only with one section of pages, more pages are added as
> - * needed until the rest of deferred pages are initialized.
> - */
> - pgdat->static_init_pgcnt = min_t(unsigned long, PAGES_PER_SECTION,
> - pgdat->node_spanned_pages);
> pgdat->first_deferred_pfn = ULONG_MAX;
> }
> #else
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH] mm: check nr_initialised with PAGES_PER_SECTION directly in defer_init()
2018-12-20 23:50 ` Alexander Duyck
@ 2018-12-21 3:39 ` Wei Yang
0 siblings, 0 replies; 4+ messages in thread
From: Wei Yang @ 2018-12-21 3:39 UTC (permalink / raw)
To: Alexander Duyck; +Cc: Wei Yang, osalvador, akpm, linux-mm
On Thu, Dec 20, 2018 at 03:50:29PM -0800, Alexander Duyck wrote:
>On Thu, 2018-11-22 at 17:48 +0800, Wei Yang wrote:
>> When DEFERRED_STRUCT_PAGE_INIT is configured, only the first section of
>> each node's highest zone is initialized before defer stage.
>>
>> static_init_pgcnt is used to store the number of pages like this:
>>
>> pgdat->static_init_pgcnt = min_t(unsigned long, PAGES_PER_SECTION,
>> pgdat->node_spanned_pages);
>>
>> because we don't want to overflow zone's range.
>>
>> But this is not necessary, since defer_init() is called like this:
>>
>> memmap_init_zone()
>> for pfn in [start_pfn, end_pfn)
>> defer_init(pfn, end_pfn)
>>
>> In case (pgdat->node_spanned_pages < PAGES_PER_SECTION), the loop would
>> stop before calling defer_init().
>>
>> BTW, comparing PAGES_PER_SECTION with node_spanned_pages is not correct,
>> since nr_initialised is zone based instead of node based. Even
>> node_spanned_pages is bigger than PAGES_PER_SECTION, its highest zone
>> would have pages less than PAGES_PER_SECTION.
>>
>> Signed-off-by: Wei Yang <richard.weiyang@gmail.com>
>
>This all seems to make sense to me, and appears to be a valid
>improvement.
>
>Reviewed-by: Alexander Duyck <alexander.h.duyck@linux.intel.com>
Thanks :-)
>
>> ---
>> include/linux/mmzone.h | 2 --
>> mm/page_alloc.c | 13 ++++++-------
>> 2 files changed, 6 insertions(+), 9 deletions(-)
>>
>> diff --git a/include/linux/mmzone.h b/include/linux/mmzone.h
>> index ae7a830a21eb..68d7b558924b 100644
>> --- a/include/linux/mmzone.h
>> +++ b/include/linux/mmzone.h
>> @@ -692,8 +692,6 @@ typedef struct pglist_data {
>> * is the first PFN that needs to be initialised.
>> */
>> unsigned long first_deferred_pfn;
>> - /* Number of non-deferred pages */
>> - unsigned long static_init_pgcnt;
>> #endif /* CONFIG_DEFERRED_STRUCT_PAGE_INIT */
>>
>> #ifdef CONFIG_TRANSPARENT_HUGEPAGE
>> diff --git a/mm/page_alloc.c b/mm/page_alloc.c
>> index 76e12179cd5e..b542d82400cf 100644
>> --- a/mm/page_alloc.c
>> +++ b/mm/page_alloc.c
>> @@ -326,8 +326,13 @@ defer_init(int nid, unsigned long pfn, unsigned long end_pfn)
>> /* Always populate low zones for address-constrained allocations */
>> if (end_pfn < pgdat_end_pfn(NODE_DATA(nid)))
>> return false;
>> +
>> + /*
>> + * We start only with one section of pages, more pages are added as
>> + * needed until the rest of deferred pages are initialized.
>> + */
>> nr_initialised++;
>> - if ((nr_initialised > NODE_DATA(nid)->static_init_pgcnt) &&
>> + if ((nr_initialised > PAGES_PER_SECTION) &&
>> (pfn & (PAGES_PER_SECTION - 1)) == 0) {
>> NODE_DATA(nid)->first_deferred_pfn = pfn;
>> return true;
>> @@ -6451,12 +6456,6 @@ static void __ref alloc_node_mem_map(struct pglist_data *pgdat) { }
>> #ifdef CONFIG_DEFERRED_STRUCT_PAGE_INIT
>> static inline void pgdat_set_deferred_range(pg_data_t *pgdat)
>> {
>> - /*
>> - * We start only with one section of pages, more pages are added as
>> - * needed until the rest of deferred pages are initialized.
>> - */
>> - pgdat->static_init_pgcnt = min_t(unsigned long, PAGES_PER_SECTION,
>> - pgdat->node_spanned_pages);
>> pgdat->first_deferred_pfn = ULONG_MAX;
>> }
>> #else
--
Wei Yang
Help you, Help me
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2018-12-21 3:39 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2018-11-22 9:48 [PATCH] mm: check nr_initialised with PAGES_PER_SECTION directly in defer_init() Wei Yang
2018-12-20 23:01 ` Andrew Morton
2018-12-20 23:50 ` Alexander Duyck
2018-12-21 3:39 ` Wei Yang
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.