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authorJack Steiner <steiner@sgi.com>2010-05-26 14:42:51 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-05-27 09:12:44 -0700
commit0ac0c0d0f837c499afd02a802f9cf52d3027fa3b (patch)
treec20a7306d4b727722556af1aa5565855686aee07 /kernel/fork.c
parent6adef3ebe570bcde67fd6c16101451ddde5712b5 (diff)
downloadop-kernel-dev-0ac0c0d0f837c499afd02a802f9cf52d3027fa3b.zip
op-kernel-dev-0ac0c0d0f837c499afd02a802f9cf52d3027fa3b.tar.gz
cpusets: randomize node rotor used in cpuset_mem_spread_node()
Some workloads that create a large number of small files tend to assign too many pages to node 0 (multi-node systems). Part of the reason is that the rotor (in cpuset_mem_spread_node()) used to assign nodes starts at node 0 for newly created tasks. This patch changes the rotor to be initialized to a random node number of the cpuset. [akpm@linux-foundation.org: fix layout] [Lee.Schermerhorn@hp.com: Define stub numa_random() for !NUMA configuration] Signed-off-by: Jack Steiner <steiner@sgi.com> Signed-off-by: Lee Schermerhorn <lee.schermerhorn@hp.com> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Pekka Enberg <penberg@cs.helsinki.fi> Cc: Paul Menage <menage@google.com> Cc: Jack Steiner <steiner@sgi.com> Cc: Robin Holt <holt@sgi.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'kernel/fork.c')
-rw-r--r--kernel/fork.c4
1 files changed, 4 insertions, 0 deletions
diff --git a/kernel/fork.c b/kernel/fork.c
index 4d57d9e..2e9cc31 100644
--- a/kernel/fork.c
+++ b/kernel/fork.c
@@ -1079,6 +1079,10 @@ static struct task_struct *copy_process(unsigned long clone_flags,
}
mpol_fix_fork_child_flag(p);
#endif
+#ifdef CONFIG_CPUSETS
+ p->cpuset_mem_spread_rotor = node_random(p->mems_allowed);
+ p->cpuset_slab_spread_rotor = node_random(p->mems_allowed);
+#endif
#ifdef CONFIG_TRACE_IRQFLAGS
p->irq_events = 0;
#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW
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