On Sat, 26 Mar 2011 17:14:44 -0700
Ying Han <yinghan@xxxxxxxxxx> wrote:
> Two new stats in per-memcg memory.stat which tracks the number of
> page faults and number of major page faults.
>
> "pgfault"
> "pgmajfault"
>
> It is valuable to track the two stats for both measuring application's
> performance as well as the efficiency of the kernel page reclaim path.
>
> Functional test: check the total number of pgfault/pgmajfault of all
> memcgs and compare with global vmstat value:
>
> $ cat /proc/vmstat | grep fault
> pgfault 1070751
> pgmajfault 553
>
> $ cat /dev/cgroup/memory.stat | grep fault
> pgfault 1069962
> pgmajfault 553
> total_pgfault 1069966
> total_pgmajfault 553
>
> $ cat /dev/cgroup/A/memory.stat | grep fault
> pgfault 199
> pgmajfault 0
> total_pgfault 199
> total_pgmajfault 0
>
> Performance test: run page fault test(pft) wit 16 thread on faulting in 15G
> anon pages in 16G container. There is no regression noticed on the "flt/cpu/s"
>
> Sample output from pft:
> TAG pft:anon-sys-default:
> Gb Thr CLine User System Wall flt/cpu/s fault/wsec
> 15 16 1 0.67s 232.11s 14.68s 16892.130 267796.518
>
> $ ./ministat mmotm.txt mmotm_fault.txt
> x mmotm.txt (w/o patch)
> + mmotm_fault.txt (w/ patch)
> +-------------------------------------------------------------------------+
> N Min Max Median Avg Stddev
> x 10 16682.962 17344.027 16913.524 16928.812 166.5362
> + 10 16696.49 17480.09 16949.143 16951.448 223.56288
> No difference proven at 95.0% confidence
>
> Signed-off-by: Ying Han <yinghan@xxxxxxxxxx>
Hmm, maybe useful ? (It's good to describe what is difference with PGPGIN)
Especially, you should show why this is useful than per process pgfault count.
What I thought of this, I thought that I need per-process information, finally...
and didn't add this.
Anyway, I have a request for the style of the function. (see below)
> ---
> Documentation/cgroups/memory.txt | 4 +++
> fs/ncpfs/mmap.c | 2 +
> include/linux/memcontrol.h | 22 +++++++++++++++
> mm/filemap.c | 1 +
> mm/memcontrol.c | 54 ++++++++++++++++++++++++++++++++++++++
> mm/memory.c | 2 +
> mm/shmem.c | 1 +
> 7 files changed, 86 insertions(+), 0 deletions(-)
>
> diff --git a/Documentation/cgroups/memory.txt b/Documentation/cgroups/memory.txt
> index b6ed61c..2db6103 100644
> --- a/Documentation/cgroups/memory.txt
> +++ b/Documentation/cgroups/memory.txt
> @@ -385,6 +385,8 @@ mapped_file - # of bytes of mapped file (includes tmpfs/shmem)
> pgpgin - # of pages paged in (equivalent to # of charging events).
> pgpgout - # of pages paged out (equivalent to # of uncharging events).
> swap - # of bytes of swap usage
> +pgfault - # of page faults.
> +pgmajfault - # of major page faults.
> inactive_anon - # of bytes of anonymous memory and swap cache memory on
> LRU list.
> active_anon - # of bytes of anonymous and swap cache memory on active
> @@ -406,6 +408,8 @@ total_mapped_file - sum of all children's "cache"
> total_pgpgin - sum of all children's "pgpgin"
> total_pgpgout - sum of all children's "pgpgout"
> total_swap - sum of all children's "swap"
> +total_pgfault - sum of all children's "pgfault"
> +total_pgmajfault - sum of all children's "pgmajfault"
> total_inactive_anon - sum of all children's "inactive_anon"
> total_active_anon - sum of all children's "active_anon"
> total_inactive_file - sum of all children's "inactive_file"
> diff --git a/fs/ncpfs/mmap.c b/fs/ncpfs/mmap.c
> index a7c07b4..adb3f45 100644
> --- a/fs/ncpfs/mmap.c
> +++ b/fs/ncpfs/mmap.c
> @@ -16,6 +16,7 @@
> #include <linux/mman.h>
> #include <linux/string.h>
> #include <linux/fcntl.h>
> +#include <linux/memcontrol.h>
>
> #include <asm/uaccess.h>
> #include <asm/system.h>
> @@ -92,6 +93,7 @@ static int ncp_file_mmap_fault(struct vm_area_struct *area,
> * -- wli
> */
> count_vm_event(PGMAJFAULT);
> + mem_cgroup_pgmajfault_from_mm(area->vm_mm);
Could you do this as mem_cgroup_count_vm_event(area->vm_mm, PGMAJFAULT) ?
<snip>
> +void mem_cgroup_pgfault_from_mm(struct mm_struct *mm)
> +{
> + struct mem_cgroup *mem;
> +
> + if (!mm)
> + return;
> +
> + rcu_read_lock();
> + mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
> + if (unlikely(!mem))
> + goto out;
> + mem_cgroup_pgfault(mem, 1);
> +
> +out:
> + rcu_read_unlock();
> +}
> +
> +void mem_cgroup_pgmajfault_from_mm(struct mm_struct *mm)
> +{
> + struct mem_cgroup *mem;
> +
> + if (!mm)
> + return;
> +
> + rcu_read_lock();
> + mem = mem_cgroup_from_task(rcu_dereference(mm->owner));
> + if (unlikely(!mem))
> + goto out;
> + mem_cgroup_pgmajfault(mem, 1);
> +out:
> + rcu_read_unlock();
> +}
> +EXPORT_SYMBOL(mem_cgroup_pgmajfault_from_mm);
> +
Then, you can do above 2 in a function.
Thanks,
-Kame
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