mm/compaction: reverse the change that forbade sync migraton with __GFP_NO_KSWAPD

It's uncertain this has been beneficial, so it's safer to undo it.  All
other compaction users would still go in synchronous mode if a first
attempt at async compaction failed.  Hopefully we don't need to force
special behavior for THP (which is the only __GFP_NO_KSWAPD user so far
and it's the easier to exercise and to be noticeable).  This also make
__GFP_NO_KSWAPD return to its original strict semantics specific to bypass
kswapd, as THP allocations have khugepaged for the async THP
allocations/compactions.

Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Cc: Alex Villacis Lasso <avillaci@fiec.espol.edu.ec>
Cc: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Andrea Arcangeli 2011-05-24 17:11:38 -07:00 committed by Linus Torvalds
parent a6cccdc36c
commit c6a140bf16

View File

@ -2107,7 +2107,7 @@ rebalance:
sync_migration);
if (page)
goto got_pg;
sync_migration = !(gfp_mask & __GFP_NO_KSWAPD);
sync_migration = true;
/* Try direct reclaim and then allocating */
page = __alloc_pages_direct_reclaim(gfp_mask, order,