* [PATCH 1/1] mm: Export a function to get vm committed memory
@ 2012-11-13 15:02 K. Y. Srinivasan
2012-11-13 21:07 ` David Rientjes
0 siblings, 1 reply; 4+ messages in thread
From: K. Y. Srinivasan @ 2012-11-13 15:02 UTC (permalink / raw)
To: gregkh, linux-kernel, devel, olaf, apw, andi, akpm, linux-mm,
kamezawa.hiroyuki, mhocko, hannes, yinghan, dan.magenheimer,
konrad.wilk
Cc: K. Y. Srinivasan
It will be useful to be able to access global memory commitment from device
drivers. On the Hyper-V platform, the host has a policy engine to balance
the available physical memory amongst all competing virtual machines
hosted on a given node. This policy engine is driven by a number of metrics
including the memory commitment reported by the guests. The balloon driver
for Linux on Hyper-V will use this function to retrieve guest memory commitment.
This function is also used in Xen self ballooning code.
Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
---
drivers/xen/xen-selfballoon.c | 2 +-
include/linux/mman.h | 2 ++
mm/mmap.c | 15 +++++++++++++++
mm/nommu.c | 16 ++++++++++++++++
4 files changed, 34 insertions(+), 1 deletions(-)
diff --git a/drivers/xen/xen-selfballoon.c b/drivers/xen/xen-selfballoon.c
index 7d041cb..2552d3e 100644
--- a/drivers/xen/xen-selfballoon.c
+++ b/drivers/xen/xen-selfballoon.c
@@ -222,7 +222,7 @@ static void selfballoon_process(struct work_struct *work)
if (xen_selfballooning_enabled) {
cur_pages = totalram_pages;
tgt_pages = cur_pages; /* default is no change */
- goal_pages = percpu_counter_read_positive(&vm_committed_as) +
+ goal_pages = vm_memory_committed() +
totalreserve_pages +
MB2PAGES(selfballoon_reserved_mb);
#ifdef CONFIG_FRONTSWAP
diff --git a/include/linux/mman.h b/include/linux/mman.h
index d09dde1..9aa863d 100644
--- a/include/linux/mman.h
+++ b/include/linux/mman.h
@@ -11,6 +11,8 @@ extern int sysctl_overcommit_memory;
extern int sysctl_overcommit_ratio;
extern struct percpu_counter vm_committed_as;
+unsigned long vm_memory_committed(void);
+
static inline void vm_acct_memory(long pages)
{
percpu_counter_add(&vm_committed_as, pages);
diff --git a/mm/mmap.c b/mm/mmap.c
index 2d94235..3dd0a17 100644
--- a/mm/mmap.c
+++ b/mm/mmap.c
@@ -89,6 +89,21 @@ int sysctl_max_map_count __read_mostly = DEFAULT_MAX_MAP_COUNT;
struct percpu_counter vm_committed_as ____cacheline_aligned_in_smp;
/*
+ * The global memory commitment made in the system can be a metric
+ * that can be used to drive ballooning decisions when Linux is hosted
+ * as a guest. On Hyper-V, the host implements a policy engine for dynamically
+ * balancing memory across competing virtual machines that are hosted.
+ * Several metrics drive this policy engine including the guest reported
+ * memory commitment.
+ */
+
+unsigned long vm_memory_committed(void)
+{
+ return percpu_counter_read_positive(&vm_committed_as);
+}
+EXPORT_SYMBOL_GPL(vm_memory_committed);
+
+/*
* Check that a process has enough memory to allocate a new virtual
* mapping. 0 means there is enough memory for the allocation to
* succeed and -ENOMEM implies there is not.
diff --git a/mm/nommu.c b/mm/nommu.c
index 45131b4..f11e703 100644
--- a/mm/nommu.c
+++ b/mm/nommu.c
@@ -66,6 +66,22 @@ int heap_stack_gap = 0;
atomic_long_t mmap_pages_allocated;
+/*
+ * The global memory commitment made in the system can be a metric
+ * that can be used to drive ballooning decisions when Linux is hosted
+ * as a guest. On Hyper-V, the host implements a policy engine for dynamically
+ * balancing memory across competing virtual machines that are hosted.
+ * Several metrics drive this policy engine including the guest reported
+ * memory commitment.
+ */
+
+unsigned long vm_memory_committed(void)
+{
+ return percpu_counter_read_positive(&vm_committed_as);
+}
+
+EXPORT_SYMBOL_GPL(vm_memory_committed);
+
EXPORT_SYMBOL(mem_map);
EXPORT_SYMBOL(num_physpages);
--
1.7.4.1
^ permalink raw reply related [flat|nested] 4+ messages in thread
* Re: [PATCH 1/1] mm: Export a function to get vm committed memory
2012-11-13 15:02 [PATCH 1/1] mm: Export a function to get vm committed memory K. Y. Srinivasan
@ 2012-11-13 21:07 ` David Rientjes
2012-11-27 21:12 ` Konrad Rzeszutek Wilk
0 siblings, 1 reply; 4+ messages in thread
From: David Rientjes @ 2012-11-13 21:07 UTC (permalink / raw)
To: K. Y. Srinivasan
Cc: gregkh, linux-kernel, devel, olaf, apw, andi, akpm, linux-mm,
kamezawa.hiroyuki, mhocko, hannes, yinghan, dan.magenheimer,
konrad.wilk
On Tue, 13 Nov 2012, K. Y. Srinivasan wrote:
> It will be useful to be able to access global memory commitment from device
> drivers. On the Hyper-V platform, the host has a policy engine to balance
> the available physical memory amongst all competing virtual machines
> hosted on a given node. This policy engine is driven by a number of metrics
> including the memory commitment reported by the guests. The balloon driver
> for Linux on Hyper-V will use this function to retrieve guest memory commitment.
> This function is also used in Xen self ballooning code.
>
> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
Acked-by: David Rientjes <rientjes@google.com>
Very nice!
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: [PATCH 1/1] mm: Export a function to get vm committed memory
2012-11-13 21:07 ` David Rientjes
@ 2012-11-27 21:12 ` Konrad Rzeszutek Wilk
0 siblings, 0 replies; 4+ messages in thread
From: Konrad Rzeszutek Wilk @ 2012-11-27 21:12 UTC (permalink / raw)
To: David Rientjes
Cc: K. Y. Srinivasan, gregkh, linux-kernel, devel, olaf, apw, andi,
akpm, linux-mm, kamezawa.hiroyuki, mhocko, hannes, yinghan,
dan.magenheimer
On Tue, Nov 13, 2012 at 01:07:30PM -0800, David Rientjes wrote:
> On Tue, 13 Nov 2012, K. Y. Srinivasan wrote:
>
> > It will be useful to be able to access global memory commitment from device
> > drivers. On the Hyper-V platform, the host has a policy engine to balance
> > the available physical memory amongst all competing virtual machines
> > hosted on a given node. This policy engine is driven by a number of metrics
> > including the memory commitment reported by the guests. The balloon driver
> > for Linux on Hyper-V will use this function to retrieve guest memory commitment.
> > This function is also used in Xen self ballooning code.
> >
> > Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
>
> Acked-by: David Rientjes <rientjes@google.com>
I am bit late to this party - and back from vacation - so not sure if this
is merged in or not. Either way:
Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> on the drivers/xen* side.
^ permalink raw reply [flat|nested] 4+ messages in thread
* RE: [PATCH 1/1] mm: Export a function to get vm committed memory
[not found] <<1352818957-9229-1-git-send-email-kys@microsoft.com>
@ 2012-11-13 15:45 ` Dan Magenheimer
0 siblings, 0 replies; 4+ messages in thread
From: Dan Magenheimer @ 2012-11-13 15:45 UTC (permalink / raw)
To: K. Y. Srinivasan, gregkh, linux-kernel, devel, olaf, apw, andi,
akpm, linux-mm, kamezawa.hiroyuki, mhocko, hannes, yinghan,
dan.magenheimer, konrad.wilk
> From: K. Y. Srinivasan [mailto:kys@microsoft.com]
> Sent: Tuesday, November 13, 2012 8:03 AM
> To: gregkh@linuxfoundation.org; linux-kernel@vger.kernel.org; devel@linuxdriverproject.org;
> olaf@aepfle.de; apw@canonical.com; andi@firstfloor.org; akpm@linux-foundation.org; linux-mm@kvack.org;
> kamezawa.hiroyuki@gmail.com; mhocko@suse.cz; hannes@cmpxchg.org; yinghan@google.com;
> dan.magenheimer@oracle.com; konrad.wilk@oracle.com
> Cc: K. Y. Srinivasan
> Subject: [PATCH 1/1] mm: Export a function to get vm committed memory
>
> It will be useful to be able to access global memory commitment from device
> drivers. On the Hyper-V platform, the host has a policy engine to balance
> the available physical memory amongst all competing virtual machines
> hosted on a given node. This policy engine is driven by a number of metrics
> including the memory commitment reported by the guests. The balloon driver
> for Linux on Hyper-V will use this function to retrieve guest memory commitment.
> This function is also used in Xen self ballooning code.
>
> Signed-off-by: K. Y. Srinivasan <kys@microsoft.com>
The patch to the Xen selfballoon driver is unnecessary, but is
one step in the direction of module support for this driver so
I am fine whether the patch is included here or not.
Acked-by: Dan Magenheimer <dan.magenheimer@oracle.com>
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2012-11-27 21:13 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
-- links below jump to the message on this page --
2012-11-13 15:02 [PATCH 1/1] mm: Export a function to get vm committed memory K. Y. Srinivasan
2012-11-13 21:07 ` David Rientjes
2012-11-27 21:12 ` Konrad Rzeszutek Wilk
[not found] <<1352818957-9229-1-git-send-email-kys@microsoft.com>
2012-11-13 15:45 ` Dan Magenheimer
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).