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author | David Rientjes <rientjes@google.com> | 2015-04-14 15:46:55 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2015-04-14 16:49:03 -0700 |
commit | 4167e9b2cf10f8a4bcda0c713ddc8bb0a18e8187 (patch) | |
tree | 744caf92870f2afa4facca7cdfbb6315e71b6592 /net/openvswitch | |
parent | b360edb43f8ed50aa7b8c9aae7d7557a1a6e32c8 (diff) | |
download | linux-4167e9b2cf10f8a4bcda0c713ddc8bb0a18e8187.tar.gz |
mm: remove GFP_THISNODE
NOTE: this is not about __GFP_THISNODE, this is only about GFP_THISNODE. GFP_THISNODE is a secret combination of gfp bits that have different behavior than expected. It is a combination of __GFP_THISNODE, __GFP_NORETRY, and __GFP_NOWARN and is special-cased in the page allocator slowpath to fail without trying reclaim even though it may be used in combination with __GFP_WAIT. An example of the problem this creates: commit e97ca8e5b864 ("mm: fix GFP_THISNODE callers and clarify") fixed up many users of GFP_THISNODE that really just wanted __GFP_THISNODE. The problem doesn't end there, however, because even it was a no-op for alloc_misplaced_dst_page(), which also sets __GFP_NORETRY and __GFP_NOWARN, and migrate_misplaced_transhuge_page(), where __GFP_NORETRY and __GFP_NOWAIT is set in GFP_TRANSHUGE. Converting GFP_THISNODE to __GFP_THISNODE is a no-op in these cases since the page allocator special-cases __GFP_THISNODE && __GFP_NORETRY && __GFP_NOWARN. It's time to just remove GFP_THISNODE entirely. We leave __GFP_THISNODE to restrict an allocation to a local node, but remove GFP_THISNODE and its obscurity. Instead, we require that a caller clear __GFP_WAIT if it wants to avoid reclaim. This allows the aforementioned functions to actually reclaim as they should. It also enables any future callers that want to do __GFP_THISNODE but also __GFP_NORETRY && __GFP_NOWARN to reclaim. The rule is simple: if you don't want to reclaim, then don't set __GFP_WAIT. Aside: ovs_flow_stats_update() really wants to avoid reclaim as well, so it is unchanged. Signed-off-by: David Rientjes <rientjes@google.com> Acked-by: Vlastimil Babka <vbabka@suse.cz> Cc: Christoph Lameter <cl@linux.com> Acked-by: Pekka Enberg <penberg@kernel.org> Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com> Acked-by: Johannes Weiner <hannes@cmpxchg.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Pravin Shelar <pshelar@nicira.com> Cc: Jarno Rajahalme <jrajahalme@nicira.com> Cc: Li Zefan <lizefan@huawei.com> Cc: Greg Thelen <gthelen@google.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'net/openvswitch')
-rw-r--r-- | net/openvswitch/flow.c | 4 |
1 files changed, 3 insertions, 1 deletions
diff --git a/net/openvswitch/flow.c b/net/openvswitch/flow.c index 50ec42f170a0..2dacc7b5af23 100644 --- a/net/openvswitch/flow.c +++ b/net/openvswitch/flow.c @@ -100,7 +100,9 @@ void ovs_flow_stats_update(struct sw_flow *flow, __be16 tcp_flags, new_stats = kmem_cache_alloc_node(flow_stats_cache, - GFP_THISNODE | + GFP_NOWAIT | + __GFP_THISNODE | + __GFP_NOWARN | __GFP_NOMEMALLOC, node); if (likely(new_stats)) { |