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authorDimitri Sivanich <sivanich@sgi.com>2009-06-23 12:37:04 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2009-06-23 12:50:05 -0700
commit364df0ebfbbb1330bfc6ca159f4d6020efc15a12 (patch)
tree80c79bf145d8388ad96a0f7c47a4d25642e403a1
parent01ff53f416757da416413bc32229770a8448b6ef (diff)
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mm: fix handling of pagesets for downed cpus
After downing/upping a cpu, an attempt to set /proc/sys/vm/percpu_pagelist_fraction results in an oops in percpu_pagelist_fraction_sysctl_handler(). If a processor is downed then we need to set the pageset pointer back to the boot pageset. Updates of the high water marks should not access pagesets of unpopulated zones (those pointer go to the boot pagesets which would be no longer functional if their size would be increased beyond zero). Signed-off-by: Dimitri Sivanich <sivanich@sgi.com> Signed-off-by: Christoph Lameter <cl@linux-foundation.org> Reviewed-by: KOSAKI Motohiro <kosaki.motohiro@jp.fujitsu.com> Cc: Nick Piggin <nickpiggin@yahoo.com.au> Cc: Mel Gorman <mel@csn.ul.ie> Cc: <stable@kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
-rw-r--r--mm/page_alloc.c6
1 files changed, 3 insertions, 3 deletions
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 30d5093a099d..aecc9cdfdfce 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -3026,7 +3026,7 @@ bad:
if (dzone == zone)
break;
kfree(zone_pcp(dzone, cpu));
- zone_pcp(dzone, cpu) = NULL;
+ zone_pcp(dzone, cpu) = &boot_pageset[cpu];
}
return -ENOMEM;
}
@@ -3041,7 +3041,7 @@ static inline void free_zone_pagesets(int cpu)
/* Free per_cpu_pageset if it is slab allocated */
if (pset != &boot_pageset[cpu])
kfree(pset);
- zone_pcp(zone, cpu) = NULL;
+ zone_pcp(zone, cpu) = &boot_pageset[cpu];
}
}
@@ -4659,7 +4659,7 @@ int percpu_pagelist_fraction_sysctl_handler(ctl_table *table, int write,
ret = proc_dointvec_minmax(table, write, file, buffer, length, ppos);
if (!write || (ret == -EINVAL))
return ret;
- for_each_zone(zone) {
+ for_each_populated_zone(zone) {
for_each_online_cpu(cpu) {
unsigned long high;
high = zone->present_pages / percpu_pagelist_fraction;