From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail.linuxfoundation.org ([140.211.169.12]:45720 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751129AbdAQQNw (ORCPT ); Tue, 17 Jan 2017 11:13:52 -0500 Subject: Patch "mm: fix remote numa hits statistics" has been added to the 4.9-stable tree To: mhocko@suse.com, akpm@linux-foundation.org, gregkh@linuxfoundation.org, hannes@cmpxchg.org, hejianet@gmail.com, iamjoonsoo.kim@lge.com, izumi.taku@jp.fujitsu.com, mgorman@suse.de, torvalds@linux-foundation.org, vbabka@suse.cz Cc: , From: Date: Tue, 17 Jan 2017 17:13:03 +0100 Message-ID: <14846695834238@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: stable-owner@vger.kernel.org List-ID: This is a note to let you know that I've just added the patch titled mm: fix remote numa hits statistics to the 4.9-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mm-fix-remote-numa-hits-statistics.patch and it can be found in the queue-4.9 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >>From 2df26639e708a88dcc22171949da638a9998f3bc Mon Sep 17 00:00:00 2001 From: Michal Hocko Date: Tue, 10 Jan 2017 16:57:39 -0800 Subject: mm: fix remote numa hits statistics From: Michal Hocko commit 2df26639e708a88dcc22171949da638a9998f3bc upstream. Jia He has noticed that commit 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@kernel.org Signed-off-by: Michal Hocko Reported-by: Jia He Reviewed-by: Vlastimil Babka # with cbmc[1] superpowers Acked-by: Mel Gorman Cc: Johannes Weiner Cc: Joonsoo Kim Cc: Taku Izumi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Greg Kroah-Hartman --- mm/page_alloc.c | 15 ++++----------- 1 file changed, 4 insertions(+), 11 deletions(-) --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2556,30 +2556,23 @@ 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 stable-queue which might be from mhocko@suse.com are queue-4.9/mm-memcg-fix-the-active-list-aging-for-lowmem-requests-when-memcg-is-enabled.patch queue-4.9/mm-fix-remote-numa-hits-statistics.patch queue-4.9/mm-pmd-dirty-emulation-in-page-fault-handler.patch