Commit 46e700ab authored by Mel Gorman's avatar Mel Gorman Committed by Linus Torvalds

mm, page_alloc: remove unnecessary taking of a seqlock when cpusets are disabled

There is a seqcounter that protects against spurious allocation failures
when a task is changing the allowed nodes in a cpuset.  There is no need
to check the seqcounter until a cpuset exists.
Signed-off-by: default avatarMel Gorman <mgorman@techsingularity.net>
Acked-by: default avatarChristoph Lameter <cl@linux.com>
Acked-by: default avatarDavid Rientjes <rientjes@google.com>
Acked-by: default avatarVlastimil Babka <vbabka@suse.cz>
Acked-by: default avatarMichal Hocko <mhocko@suse.com>
Acked-by: default avatarJohannes Weiner <hannes@cmpxchg.org>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent c9ab0c4f
......@@ -104,6 +104,9 @@ extern void cpuset_print_current_mems_allowed(void);
*/
static inline unsigned int read_mems_allowed_begin(void)
{
if (!cpusets_enabled())
return 0;
return read_seqcount_begin(&current->mems_allowed_seq);
}
......@@ -115,6 +118,9 @@ static inline unsigned int read_mems_allowed_begin(void)
*/
static inline bool read_mems_allowed_retry(unsigned int seq)
{
if (!cpusets_enabled())
return false;
return read_seqcount_retry(&current->mems_allowed_seq, seq);
}
......
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