From: Shaohua Li <shli@xxxxxx> Subject: proc: show MADV_FREE pages info in smaps 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. [mhocko@xxxxxxxxxx: update Documentation/filesystems/proc.txt] Link: http://lkml.kernel.org/r/89efde633559de1ec07444f2ef0f4963a97a2ce8.1487965799.git.shli@xxxxxx Signed-off-by: Shaohua Li <shli@xxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx> Acked-by: Minchan Kim <minchan@xxxxxxxxxx> Acked-by: Michal Hocko <mhocko@xxxxxxxx> Acked-by: Hillf Danton <hillf.zj@xxxxxxxxxxxxxxx> Cc: Hugh Dickins <hughd@xxxxxxxxxx> Cc: Rik van Riel <riel@xxxxxxxxxx> Cc: Mel Gorman <mgorman@xxxxxxxxxxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- Documentation/filesystems/proc.txt | 6 ++++++ fs/proc/task_mmu.c | 8 +++++++- 2 files changed, 13 insertions(+), 1 deletion(-) diff -puN Documentation/filesystems/proc.txt~proc-show-madv_free-pages-info-in-smaps Documentation/filesystems/proc.txt --- a/Documentation/filesystems/proc.txt~proc-show-madv_free-pages-info-in-smaps +++ a/Documentation/filesystems/proc.txt @@ -413,6 +413,7 @@ 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 @@ -442,6 +443,11 @@ 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. Please note that the printed value might +be lower than the real value due to optimizations used in the current +implementation. If this is not desirable please file a bug report. "AnonHugePages" shows the ammount of memory backed by transparent hugepage. "ShmemPmdMapped" shows the ammount of shared (shmem/tmpfs) memory backed by huge pages. diff -puN fs/proc/task_mmu.c~proc-show-madv_free-pages-info-in-smaps fs/proc/task_mmu.c --- a/fs/proc/task_mmu.c~proc-show-madv_free-pages-info-in-smaps +++ a/fs/proc/task_mmu.c @@ -441,6 +441,7 @@ 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; @@ -457,8 +458,11 @@ static void smaps_account(struct mem_siz 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. */ @@ -771,6 +775,7 @@ static int show_smap(struct seq_file *m, "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" @@ -789,6 +794,7 @@ static int show_smap(struct seq_file *m, 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, _ -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
