Vlastimil Babka f8c9301fa5 mm/compaction: do not count migratepages when unnecessary ... During compaction, update_nr_listpages() has been used to count remaining non-migrated and free pages after a call to migrage_pages(). The freepages counting has become unneccessary, and it turns out that migratepages counting is also unnecessary in most cases. The only situation when it's needed to count cc->migratepages is when migrate_pages() returns with a negative error code. Otherwise, the non-negative return value is the number of pages that were not migrated, which is exactly the count of remaining pages in the cc->migratepages list. Furthermore, any non-zero count is only interesting for the tracepoint of mm_compaction_migratepages events, because after that all remaining unmigrated pages are put back and their count is set to 0. This patch therefore removes update_nr_listpages() completely, and changes the tracepoint definition so that the manual counting is done only when the tracepoint is enabled, and only when migrate_pages() returns a negative error code. Furthermore, migrate_pages() and the tracepoints won't be called when there's nothing to migrate. This potentially avoids some wasted cycles and reduces the volume of uninteresting mm_compaction_migratepages events where "nr_migrated=0 nr_failed=0". In the stress-highalloc mmtest, this was about 75% of the events. The mm_compaction_isolate_migratepages event is better for determining that nothing was isolated for migration, and this one was just duplicating the info. Signed-off-by: Vlastimil Babka <vbabka@suse.cz> Reviewed-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Cc: Minchan Kim <minchan@kernel.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com> Acked-by: Michal Nazarewicz <mina86@mina86.com> Cc: Christoph Lameter <cl@linux.com> Cc: Rik van Riel <riel@redhat.com> Acked-by: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>		2014-06-04 16:54:07 -07:00
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9p.h
asoc.h
bcache.h
block.h
btrfs.h
compaction.h	mm/compaction: do not count migratepages when unnecessary	2014-06-04 16:54:07 -07:00
context_tracking.h
ext3.h
ext4.h
f2fs.h
filelock.h
filemap.h
gfpflags.h
gpio.h
host1x.h
hswadsp.h
i2c.h
intel-sst.h
iommu.h
irq.h
jbd.h
jbd2.h
kmem.h
kvm.h
lock.h
mce.h
migrate.h
module.h
napi.h
net.h
nmi.h
oom.h
pagemap.h
power.h
power_cpu_migrate.h
printk.h
random.h
ras.h
rcu.h
regmap.h
regulator.h
rpm.h
sched.h
scsi.h
signal.h
skb.h
sock.h
spi.h
sunrpc.h
swiotlb.h
syscalls.h
target.h
task.h
timer.h
udp.h
v4l2.h
vmscan.h	mm: shrinker: add nid to tracepoint output	2014-06-04 16:54:04 -07:00
workqueue.h
writeback.h
xen.h