On Fri 24-02-17 13:31:49, Shaohua Li wrote:
> show MADV_FREE pages info of each vma in smaps. The interface is for
> diganose or monitoring purpose, userspace could use it to understand
> what happens in the application. Since userspace could dirty MADV_FREE
> pages without notice from kernel, this interface is the only place we
> can get accurate accounting info about MADV_FREE pages.
>
> Cc: Michal Hocko <mho...@suse.com>
> Cc: Hugh Dickins <hu...@google.com>
> Cc: Rik van Riel <r...@redhat.com>
> Cc: Mel Gorman <mgor...@techsingularity.net>
> Cc: Andrew Morton <a...@linux-foundation.org>
> Acked-by: Johannes Weiner <han...@cmpxchg.org>
> Acked-by: Minchan Kim <minc...@kernel.org>
> Signed-off-by: Shaohua Li <s...@fb.com>
Acked-by: Michal Hocko <mho...@suse.com>
> ---
> Documentation/filesystems/proc.txt | 4 ++++
> fs/proc/task_mmu.c | 8 +++++++-
> 2 files changed, 11 insertions(+), 1 deletion(-)
>
> diff --git a/Documentation/filesystems/proc.txt
> b/Documentation/filesystems/proc.txt
> index c94b467..45853e1 100644
> --- a/Documentation/filesystems/proc.txt
> +++ b/Documentation/filesystems/proc.txt
> @@ -412,6 +412,7 @@ Private_Clean: 0 kB
> Private_Dirty: 0 kB
> Referenced: 892 kB
> Anonymous: 0 kB
> +LazyFree: 0 kB
> AnonHugePages: 0 kB
> ShmemPmdMapped: 0 kB
> Shared_Hugetlb: 0 kB
> @@ -441,6 +442,9 @@ accessed.
> "Anonymous" shows the amount of memory that does not belong to any file.
> Even
> a mapping associated with a file may contain anonymous pages: when
> MAP_PRIVATE
> and a page is modified, the file page is replaced by a private anonymous
> copy.
> +"LazyFree" shows the amount of memory which is marked by madvise(MADV_FREE).
> +The memory isn't freed immediately with madvise(). It's freed in memory
> +pressure if the memory is clean.
> "AnonHugePages" shows the ammount of memory backed by transparent hugepage.
> "ShmemPmdMapped" shows the ammount of shared (shmem/tmpfs) memory backed by
> huge pages.
> diff --git a/fs/proc/task_mmu.c b/fs/proc/task_mmu.c
> index ee3efb2..8a5ec00 100644
> --- a/fs/proc/task_mmu.c
> +++ b/fs/proc/task_mmu.c
> @@ -440,6 +440,7 @@ struct mem_size_stats {
> unsigned long private_dirty;
> unsigned long referenced;
> unsigned long anonymous;
> + unsigned long lazyfree;
> unsigned long anonymous_thp;
> unsigned long shmem_thp;
> unsigned long swap;
> @@ -456,8 +457,11 @@ static void smaps_account(struct mem_size_stats *mss,
> struct page *page,
> int i, nr = compound ? 1 << compound_order(page) : 1;
> unsigned long size = nr * PAGE_SIZE;
>
> - if (PageAnon(page))
> + if (PageAnon(page)) {
> mss->anonymous += size;
> + if (!PageSwapBacked(page) && !dirty && !PageDirty(page))
> + mss->lazyfree += size;
> + }
>
> mss->resident += size;
> /* Accumulate the size in pages that have been accessed. */
> @@ -770,6 +774,7 @@ static int show_smap(struct seq_file *m, void *v, int
> is_pid)
> "Private_Dirty: %8lu kB\n"
> "Referenced: %8lu kB\n"
> "Anonymous: %8lu kB\n"
> + "LazyFree: %8lu kB\n"
> "AnonHugePages: %8lu kB\n"
> "ShmemPmdMapped: %8lu kB\n"
> "Shared_Hugetlb: %8lu kB\n"
> @@ -788,6 +793,7 @@ static int show_smap(struct seq_file *m, void *v, int
> is_pid)
> mss.private_dirty >> 10,
> mss.referenced >> 10,
> mss.anonymous >> 10,
> + mss.lazyfree >> 10,
> mss.anonymous_thp >> 10,
> mss.shmem_thp >> 10,
> mss.shared_hugetlb >> 10,
> --
> 2.9.3
>
--
Michal Hocko
SUSE Labs
