linux-kernel - [PATCH] page_alloc: skip cpuset enforcement for lower zone allocations

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Message-ID: <20140523193706.GA22854@amt.cnet>
Date:	Fri, 23 May 2014 16:37:07 -0300
From:	Marcelo Tosatti <mtosatti@...hat.com>
To:	linux-mm@...ck.org, linux-kernel@...r.kernel.org
Cc:	Lai Jiangshan <laijs@...fujitsu.com>, Mel Gorman <mgorman@...e.de>,
	Tejun Heo <tj@...nel.org>, Christoph Lameter <cl@...ux.com>,
	David Rientjes <rientjes@...gle.com>,
	Andrew Morton <akpm@...ux-foundation.org>
Subject: [PATCH] page_alloc: skip cpuset enforcement for lower zone
 allocations 


Zone specific allocations, such as GFP_DMA32, should not be restricted
to cpusets allowed node list: the zones which such allocations demand
might be contained in particular nodes outside the cpuset node list.

The alternative would be to not perform such allocations from
applications which are cpuset restricted, which is unrealistic.

Fixes KVM's alloc_page(gfp_mask=GFP_DMA32) with cpuset as explained.

Signed-off-by: Marcelo Tosatti <mtosatti@...hat.com>

diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 5dba293..f228039 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -2698,6 +2698,7 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 	unsigned int cpuset_mems_cookie;
 	int alloc_flags = ALLOC_WMARK_LOW|ALLOC_CPUSET|ALLOC_FAIR;
 	struct mem_cgroup *memcg = NULL;
+	nodemask_t *cpuset_mems_allowed = &cpuset_current_mems_allowed;
 
 	gfp_mask &= gfp_allowed_mask;
 
@@ -2726,9 +2727,14 @@ __alloc_pages_nodemask(gfp_t gfp_mask, unsigned int order,
 retry_cpuset:
 	cpuset_mems_cookie = read_mems_allowed_begin();
 
+#ifdef CONFIG_NUMA
+	if (gfp_zone(gfp_mask) < policy_zone)
+		cpuset_mems_allowed = NULL;
+#endif
+
 	/* The preferred zone is used for statistics later */
 	first_zones_zonelist(zonelist, high_zoneidx,
-				nodemask ? : &cpuset_current_mems_allowed,
+				nodemask ? : cpuset_mems_allowed,
 				&preferred_zone);
 	if (!preferred_zone)
 		goto out;
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/