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author | 2015-11-06 16:28:15 -0800 | |
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committer | 2015-11-06 17:50:42 -0800 | |
commit | 46e700abc44ce215acb4341d9702ce3972eda571 (patch) | |
tree | 6730677333bd4a69a014cf87fc6e40207b8cab1c /include/linux/cpuset.h | |
parent | mm, page_alloc: remove unnecessary recalculations for dirty zone balancing (diff) | |
download | linux-46e700abc44ce215acb4341d9702ce3972eda571.tar.gz linux-46e700abc44ce215acb4341d9702ce3972eda571.tar.bz2 linux-46e700abc44ce215acb4341d9702ce3972eda571.zip |
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: Mel Gorman <mgorman@techsingularity.net>
Acked-by: Christoph Lameter <cl@linux.com>
Acked-by: David Rientjes <rientjes@google.com>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Cc: Vitaly Wool <vitalywool@gmail.com>
Cc: Rik van Riel <riel@redhat.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/cpuset.h')
-rw-r--r-- | include/linux/cpuset.h | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/include/linux/cpuset.h b/include/linux/cpuset.h index 5a1311942358..85a868ccb493 100644 --- a/include/linux/cpuset.h +++ b/include/linux/cpuset.h @@ -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(¤t->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(¤t->mems_allowed_seq, seq); } |