+ mm-fix-remote-numa-hits-statistics.patch added to -mm tree

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



The patch titled
     Subject: mm: fix remote numa hits statistics
has been added to the -mm tree.  Its filename is
     mm-fix-remote-numa-hits-statistics.patch

This patch should soon appear at
    http://ozlabs.org/~akpm/mmots/broken-out/mm-fix-remote-numa-hits-statistics.patch
and later at
    http://ozlabs.org/~akpm/mmotm/broken-out/mm-fix-remote-numa-hits-statistics.patch

Before you just go and hit "reply", please:
   a) Consider who else should be cc'ed
   b) Prefer to cc a suitable mailing list as well
   c) Ideally: find the original patch on the mailing list and do a
      reply-to-all to that, adding suitable additional cc's

*** Remember to use Documentation/SubmitChecklist when testing your code ***

The -mm tree is included into linux-next and is updated
there every 3-4 working days

------------------------------------------------------
From: Michal Hocko <mhocko@xxxxxxxx>
Subject: mm: fix remote numa hits statistics

Jia He has noticed that b9f00e147f27 ("mm, page_alloc: reduce branches in
zone_statistics") has an unintentional side effect that remote node
allocation requests are accounted as NUMA_MISS rathat than NUMA_HIT and
NUMA_OTHER if such a request doesn't use __GFP_OTHER_NODE.  There are many
of these potentially because the flag is used very rarely while we have
many users of __alloc_pages_node.

Fix this by simply ignoring __GFP_OTHER_NODE (it can be removed in a
follow up patch) and treat all allocations that were satisfied from the
preferred zone's node as NUMA_HITS because this is the same node we
requested the allocation from in most cases.  If this is not the local
node then we just account it as NUMA_OTHER rather than NUMA_LOCAL.

One downsize would be that an allocation request for a node which is
outside of the mempolicy nodemask would be reported as a hit which is a
bit weird but that was the case before b9f00e147f27 already.

Fixes: b9f00e147f27 ("mm, page_alloc: reduce branches in zone_statistics")
Link: http://lkml.kernel.org/r/20170102153057.9451-2-mhocko@xxxxxxxxxx
Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>
Reported-by: Jia He <hejianet@xxxxxxxxx>
Reviewed-by: Vlastimil Babka <vbabka@xxxxxxx> # with cbmc[1] superpowers
Acked-by: Mel Gorman <mgorman@xxxxxxx>
Cc: Johannes Weiner <hannes@xxxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Taku Izumi <izumi.taku@xxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---

 mm/page_alloc.c |   15 ++++-----------
 1 file changed, 4 insertions(+), 11 deletions(-)

diff -puN mm/page_alloc.c~mm-fix-remote-numa-hits-statistics mm/page_alloc.c
--- a/mm/page_alloc.c~mm-fix-remote-numa-hits-statistics
+++ a/mm/page_alloc.c
@@ -2583,30 +2583,23 @@ int __isolate_free_page(struct page *pag
  * Update NUMA hit/miss statistics
  *
  * Must be called with interrupts disabled.
- *
- * When __GFP_OTHER_NODE is set assume the node of the preferred
- * zone is the local node. This is useful for daemons who allocate
- * memory on behalf of other processes.
  */
 static inline void zone_statistics(struct zone *preferred_zone, struct zone *z,
 								gfp_t flags)
 {
 #ifdef CONFIG_NUMA
-	int local_nid = numa_node_id();
 	enum zone_stat_item local_stat = NUMA_LOCAL;
 
-	if (unlikely(flags & __GFP_OTHER_NODE)) {
+	if (z->node != numa_node_id())
 		local_stat = NUMA_OTHER;
-		local_nid = preferred_zone->node;
-	}
 
-	if (z->node == local_nid) {
+	if (z->node == preferred_zone->node)
 		__inc_zone_state(z, NUMA_HIT);
-		__inc_zone_state(z, local_stat);
-	} else {
+	else {
 		__inc_zone_state(z, NUMA_MISS);
 		__inc_zone_state(preferred_zone, NUMA_FOREIGN);
 	}
+	__inc_zone_state(z, local_stat);
 #endif
 }
 
_

Patches currently in -mm which might be from mhocko@xxxxxxxx are

mm-slab-make-sure-that-kmalloc_max_size-will-fit-into-max_order.patch
bpf-do-not-use-kmalloc_shift_max.patch
mm-fix-remote-numa-hits-statistics.patch
mm-get-rid-of-__gfp_other_node.patch
mm-throttle-show_mem-from-warn_alloc.patch
mm-trace-extract-compaction_status-and-zone_type-to-a-common-header.patch
oom-trace-add-oom-detection-tracepoints.patch
oom-trace-add-compaction-retry-tracepoint.patch

--
To unsubscribe from this list: send the line "unsubscribe mm-commits" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html



[Index of Archives]     [Kernel Archive]     [IETF Annouce]     [DCCP]     [Netdev]     [Networking]     [Security]     [Bugtraq]     [Yosemite]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Linux SCSI]

  Powered by Linux