diff options
| author | Vladimir Davydov <vdavydov@parallels.com> | 2015-09-09 15:35:48 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-09-10 13:29:01 -0700 |
| commit | f074a8f49eb87cde95ac9d040ad5e7ea4f029738 (patch) | |
| tree | c78d0a5386ee6d9db9de32c733df404e783088d5 /fs | |
| parent | 33c3fc71c8cfa3cc3a98beaa901c069c177dc295 (diff) | |
proc: export idle flag via kpageflags
As noted by Minchan, a benefit of reading idle flag from /proc/kpageflags
is that one can easily filter dirty and/or unevictable pages while
estimating the size of unused memory.
Note that idle flag read from /proc/kpageflags may be stale in case the
page was accessed via a PTE, because it would be too costly to iterate
over all page mappings on each /proc/kpageflags read to provide an
up-to-date value. To make sure the flag is up-to-date one has to read
/sys/kernel/mm/page_idle/bitmap first.
Signed-off-by: Vladimir Davydov <vdavydov@parallels.com>
Reviewed-by: Andres Lagar-Cavilla <andreslc@google.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Greg Thelen <gthelen@google.com>
Cc: Michel Lespinasse <walken@google.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Pavel Emelyanov <xemul@parallels.com>
Cc: Cyrill Gorcunov <gorcunov@openvz.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/proc/page.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/fs/proc/page.c b/fs/proc/page.c index c2d29edcaa6b..0b8286450a93 100644 --- a/fs/proc/page.c +++ b/fs/proc/page.c @@ -150,6 +150,9 @@ u64 stable_page_flags(struct page *page) if (PageBalloon(page)) u |= 1 << KPF_BALLOON; + if (page_is_idle(page)) + u |= 1 << KPF_IDLE; + u |= kpf_copy_bit(k, KPF_LOCKED, PG_locked); u |= kpf_copy_bit(k, KPF_SLAB, PG_slab); |