mm: fix zone_watermark_ok_safe() accounting of isolated pages
authorBartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Fri, 4 Jan 2013 23:35:08 +0000 (15:35 -0800)
committerLinus Torvalds <torvalds@linux-foundation.org>
Sat, 5 Jan 2013 00:11:46 +0000 (16:11 -0800)
commita458431e176ddb27e8ef8b98c2a681b217337393
tree466ec91a25ebbe30870d12486071bb08a8c7cd5a
parent358e419f826b552c9d795bcd3820597217692461
mm: fix zone_watermark_ok_safe() accounting of isolated pages

Commit 702d1a6e0766 ("memory-hotplug: fix kswapd looping forever
problem") added an isolated pageblocks counter (nr_pageblock_isolate in
struct zone) and used it to adjust free pages counter in
zone_watermark_ok_safe() to prevent kswapd looping forever problem.

Then later, commit 2139cbe627b8 ("cma: fix counting of isolated pages")
fixed accounting of isolated pages in global free pages counter.  It
made the previous zone_watermark_ok_safe() fix unnecessary and
potentially harmful (cause now isolated pages may be accounted twice
making free pages counter incorrect).

This patch removes the special isolated pageblocks counter altogether
which fixes zone_watermark_ok_safe() free pages check.

Reported-by: Tomasz Stanislawski <t.stanislaws@samsung.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Minchan Kim <minchan@kernel.org>
Cc: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com>
Cc: Aaditya Kumar <aaditya.kumar.30@gmail.com>
Cc: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Mel Gorman <mgorman@suse.de>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: Michal Nazarewicz <mina86@mina86.com>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
include/linux/mmzone.h
mm/page_alloc.c
mm/page_isolation.c