tree 08f27c0b46aa19114faeb4c64b5eabcc8e2ba54e
parent 51dcc81c282dc401dfd8460a7e59546bc1b30e32
author Vlastimil Babka <vbabka@suse.cz> 1596781516 -0700
committer Linus Torvalds <torvalds@linux-foundation.org> 1596825208 -0700

mm, page_alloc: use unlikely() in task_capc()

Hugh noted that task_capc() could use unlikely(), as most of the time
there is no capture in progress and we are in page freeing hot path.
Indeed adding unlikely() produces assembly that better matches the
assumption and moves all the tests away from the hot path.

I have also noticed that we don't need to test for cc->direct_compaction
as the only place we set current->task_capture is compact_zone_order()
which also always sets cc->direct_compaction true.

Suggested-by: Hugh Dickins <hughd@google.com>
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Acked-by: Hugh Dickins <hughd@googlecom>
Acked-by: Mel Gorman <mgorman@techsingularity.net>
Cc: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Li Wang <liwang@redhat.com>
Link: http://lkml.kernel.org/r/4a24f7af-3aa5-6e80-4ae6-8f253b562039@suse.cz
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>