[PATCH 1/1] fs/proc: cached = pagecache - shmem

[Adrian Brzezinski <adrian.brzezinski@eo.pl>]

Cached value taken from /proc/meminfo counts also shmem pages.
This can be very confusing when we encounter OOM problems.

Maybe the better solution would be, to not increment NR_FILE_PAGES,
when we have NR_SHMEM page? Should I rewrote and resend this patch?

Signed-off-by: Adrian Brzezinski <adrian.brzezinski@eo.pl>
---
 fs/proc/meminfo.c |    7 +++++++
 1 files changed, 7 insertions(+), 0 deletions(-)

diff --git a/fs/proc/meminfo.c b/fs/proc/meminfo.c
index 5aa847a..d00aef5 100644
--- a/fs/proc/meminfo.c
+++ b/fs/proc/meminfo.c
@@ -40,7 +40,12 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
        allowed = ((totalram_pages - hugetlb_total_pages())
                * sysctl_overcommit_ratio / 100) + total_swap_pages;

+       /*
+        * NR_SHMEM pages can't be treated as a cache,
+        * but they are counted in NR_FILE_PAGES
+        */
        cached = global_page_state(NR_FILE_PAGES) -
+                       global_page_state(NR_SHMEM) -
                        total_swapcache_pages() - i.bufferram;
        if (cached < 0)
                cached = 0;
@@ -59,6 +64,7 @@ static int meminfo_proc_show(struct seq_file *m, void *v)
                "Buffers:        %8lu kB\n"
                "Cached:         %8lu kB\n"
                "SwapCached:     %8lu kB\n"
+               "PageCache:      %8lu kB\n"
                "Active:         %8lu kB\n"
                "Inactive:       %8lu kB\n"
                "Active(anon):   %8lu kB\n"
@@ -111,6 +117,7 @@ static int meminfo_proc_show(struct seq_file *m,
void *v)
                K(i.bufferram),
                K(cached),
                K(total_swapcache_pages()),
+               K(global_page_state(NR_FILE_PAGES)),
                K(pages[LRU_ACTIVE_ANON]   + pages[LRU_ACTIVE_FILE]),
                K(pages[LRU_INACTIVE_ANON] + pages[LRU_INACTIVE_FILE]),
                K(pages[LRU_ACTIVE_ANON]),
--
1.7.1