Messages in this thread Patch in this message | | | Date | Thu, 3 Jul 2008 09:44:27 -0700 (PDT) | From | Linus Torvalds <> | Subject | Re: [PATCH] Do not clobber pgdat->nr_zones during memory initialisation |
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On Thu, 3 Jul 2008, Mel Gorman wrote: > > Subject: [PATCH] Do not clobber pgdat->nr_zones during memory initialisation
Heh. I already applied it as ObviouslyCorrect(tm), but did the simplification I already pointed out (and which your second version already had) and rewrote your commit message a bit. So it's now committed as follows..
Linus
--- commit 494de90098784b8e2797598cefdd34188884ec2e Author: Mel Gorman <mel@csn.ul.ie> Date: Thu Jul 3 05:27:51 2008 +0100
Do not overwrite nr_zones on !NUMA when initialising zlcache_ptr The non-NUMA case of build_zonelist_cache() would initialize the zlcache_ptr for both node_zonelists[] to NULL. Which is problematic, since non-NUMA only has a single node_zonelists[] entry, and trying to zero the non-existent second one just overwrote the nr_zones field instead. As kswapd uses this value to determine what reclaim work is necessary, the result is that kswapd never reclaims. This causes processes to stall frequently in low-memory situations as they always direct reclaim. This patch initialises zlcache_ptr correctly. Signed-off-by: Mel Gorman <mel@csn.ul.ie> Tested-by: Dan Williams <dan.j.williams@intel.com> [ Simplified patch a bit ] Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org> --- mm/page_alloc.c | 1 - 1 files changed, 0 insertions(+), 1 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 2f55295..f32fae3 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -2328,7 +2328,6 @@ static void build_zonelists(pg_data_t *pgdat) static void build_zonelist_cache(pg_data_t *pgdat) { pgdat->node_zonelists[0].zlcache_ptr = NULL; - pgdat->node_zonelists[1].zlcache_ptr = NULL; } #endif /* CONFIG_NUMA */
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