mm, page_alloc: Restore the original nodemask if the fast path allocation failed
Subsystems (2)
PATCH 1/1 mm, page_alloc: Restore the original nodemask if the fast path allocation failed
(Andrew, this is on top of the pagealloc optimisation series in mmotm. It
could be classed as a fix-up but it's subtle enough that it deserves its own changelog. "Clever" fixes had other consequences.)
The page allocator fast path uses either the requested nodemask or cpuset_current_mems_allowed if cpusets are enabled. If the allocation context allows watermarks to be ignored then it can also ignore memory policies. However, on entering the allocator slowpath the nodemask may still be cpuset_current_mems_allowed and the policies are enforced. This patch resets the nodemask appropriately before entering the slowpath.
Signed-off-by Vlastimil Babka <[email protected]>
Signed-off-by Mel Gorman <[email protected]>
mm/page_alloc.c +6 -0
@@ -3637,6 +3637,12 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order, alloc_mask =memalloc_noio_flags (gfp_mask); ac.spread_dirty_pages = false; +/* +* Restore the original nodemask if it was potentially replaced with +* &cpuset_current_mems_allowed to optimize the fast-path attempt. +*/ +if (cpusets_enabled ()) + ac.nodemask = nodemask; page =__alloc_pages_slowpath (alloc_mask, order, &ac); no_zone:
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Mel Gorman SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to [email protected]. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"[email protected]"> [email protected] </a>