Messages in this thread Patch in this message | | | Date | Tue, 11 Mar 2008 21:12:19 +0000 (GMT) | From | Hugh Dickins <> | Subject | [PATCH rc5-mm1 1/3] mm-have-zonelist: fix memcg ooms |
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Memcgroups up against their limit were OOMing unjustifiably on x86_32 with highmem: pages ripe for freeing were not being found.
It's because the zonelist changes in vmscan.c now derive zone from gfp_mask, and the gfp mask being passed into try_to_free_mem_cgroup_pages is atuned to allocating a struct page_cgroup (__GFP_HIGHMEM masked off), whereas here we need to be scanning highmem zones.
Frankenstein a gfp_mask from GFP_HIGHUSER_MOVABLE and the mask passed in.
Signed-off-by: Hugh Dickins <hugh@veritas.com> --- Same error was in -rc3-mm1, sorry for not sending fix in time for -rc5-mm1. The error comes 1 or 4 patches earlier, but this patch atop 2.6.25-rc5-mm1 fits best just after mm-have-zonelist-contains-structs-with-both-a-zone-pointer-and-zone_idx.patch
I've other GFP masking fixes or cleanups to come another day: this fixes just one clear bug, peculiar to the -mm tree, orthogonal to the rest. But two little do_try_to_free_pages cleanups follow on from this...
mm/vmscan.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
--- 2.6.25-rc5-mm1/mm/vmscan.c 2008-03-11 14:19:36.000000000 +0000 +++ linux/mm/vmscan.c 2008-03-11 20:09:05.000000000 +0000 @@ -1444,7 +1444,6 @@ unsigned long try_to_free_mem_cgroup_pag gfp_t gfp_mask) { struct scan_control sc = { - .gfp_mask = gfp_mask, .may_writepage = !laptop_mode, .may_swap = 1, .swap_cluster_max = SWAP_CLUSTER_MAX, @@ -1454,9 +1453,10 @@ unsigned long try_to_free_mem_cgroup_pag .isolate_pages = mem_cgroup_isolate_pages, }; struct zonelist *zonelist; - int target_zone = gfp_zonelist(GFP_HIGHUSER_MOVABLE); - zonelist = &NODE_DATA(numa_node_id())->node_zonelists[target_zone]; + sc.gfp_mask = (gfp_mask & GFP_RECLAIM_MASK) | + (GFP_HIGHUSER_MOVABLE & ~GFP_RECLAIM_MASK); + zonelist = NODE_DATA(numa_node_id())->node_zonelists; if (do_try_to_free_pages(zonelist, sc.gfp_mask, &sc)) return 1; return 0;
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