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 <>
Acked-by: default avatarChristoph Lameter <>
Acked-by: default avatarDavid Rientjes <>
Acked-by: default avatarVlastimil Babka <>
Acked-by: default avatarMichal Hocko <>
Acked-by: default avatarJohannes Weiner <>
Cc: Vitaly Wool <>
Cc: Rik van Riel <>
Signed-off-by: default avatarAndrew Morton <>
Signed-off-by: default avatarLinus Torvalds <>
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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