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author | Andrew Morton <akpm@linux-foundation.org> | 2016-05-19 17:11:43 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-05-19 19:12:14 -0700 |
commit | fee83b3aba4b7ddb0cb1497a04ddebcaa43f236e (patch) | |
tree | f0b43899dfc3383cf8c73c10eaf9079972066f87 | |
parent | 54f18d35263334ebcc6bf409fee3c0c8c22e5588 (diff) | |
download | op-kernel-dev-fee83b3aba4b7ddb0cb1497a04ddebcaa43f236e.zip op-kernel-dev-fee83b3aba4b7ddb0cb1497a04ddebcaa43f236e.tar.gz |
mm/mempolicy.c:offset_il_node() document and clarify
This code was pretty obscure and was relying upon obscure side-effects
of next_node(-1, ...) and was relying upon NUMA_NO_NODE being equal to
-1.
Clean that all up and document the function's intent.
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Xishi Qiu <qiuxishi@huawei.com>
Cc: Joonsoo Kim <js1304@gmail.com>
Cc: David Rientjes <rientjes@google.com>
Cc: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com>
Cc: Laura Abbott <lauraa@codeaurora.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r-- | mm/mempolicy.c | 20 |
1 files changed, 11 insertions, 9 deletions
diff --git a/mm/mempolicy.c b/mm/mempolicy.c index 8d369ce..7f80ebc 100644 --- a/mm/mempolicy.c +++ b/mm/mempolicy.c @@ -1758,23 +1758,25 @@ unsigned int mempolicy_slab_node(void) } } -/* Do static interleaving for a VMA with known offset. */ +/* + * Do static interleaving for a VMA with known offset @n. Returns the n'th + * node in pol->v.nodes (starting from n=0), wrapping around if n exceeds the + * number of present nodes. + */ static unsigned offset_il_node(struct mempolicy *pol, - struct vm_area_struct *vma, unsigned long off) + struct vm_area_struct *vma, unsigned long n) { unsigned nnodes = nodes_weight(pol->v.nodes); unsigned target; - int c; - int nid = NUMA_NO_NODE; + int i; + int nid; if (!nnodes) return numa_node_id(); - target = (unsigned int)off % nnodes; - c = 0; - do { + target = (unsigned int)n % nnodes; + nid = first_node(pol->v.nodes); + for (i = 0; i < target; i++) nid = next_node(nid, pol->v.nodes); - c++; - } while (c <= target); return nid; } |