PATCH restore interleaving of bootmem huge pages
Against: 2.6.31-rc1-mmotm-090625-1549
atop the "hugetlb-balance-freeing-of-huge-pages-across-node" series
I noticed that alloc_bootmem_huge_page() will only advance to the
next node on failure to allocate a huge page, potentially filling
nodes with huge-pages. I asked about this on linux-mm and linux-numa,
cc'ing the usual huge page suspects.
Mel Gorman responded:
I strongly suspect that the same node being used until allocation
failure instead of round-robin is an oversight and not deliberate
at all. It appears to be a side-effect of a fix made way back in
commit 63b4613c3f0d4b724ba259dc6c201bb68b884e1a ["hugetlb: fix
hugepage allocation with memoryless nodes"]. Prior to that patch
it looked like allocations would always round-robin even when
allocation was successful.
This patch--factored out of my "hugetlb mempolicy" series--moves the
advance of the hstate next node from which to allocate up before the
test for success of the attempted allocation.
Note that alloc_bootmem_huge_page() is only used for order > MAX_ORDER
huge pages.
I'll post a separate patch for mainline/stable, as the above mentioned
"balance freeing" series renamed the next node to alloc function.
Signed-off-by: Lee Schermerhorn <lee.schermerhorn@xxxxxx>
mm/hugetlb.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
Index: linux-2.6.31-rc1-mmotm-090625-1549/mm/hugetlb.c
===================================================================
--- linux-2.6.31-rc1-mmotm-090625-1549.orig/mm/hugetlb.c 2009-07-13 09:05:22.000000000 -0400
+++ linux-2.6.31-rc1-mmotm-090625-1549/mm/hugetlb.c 2009-07-13 09:06:22.000000000 -0400
@@ -1030,6 +1030,7 @@ int __weak alloc_bootmem_huge_page(struc
NODE_DATA(h->next_nid_to_alloc),
huge_page_size(h), huge_page_size(h), 0);
+ hstate_next_node_to_alloc(h);
if (addr) {
/*
* Use the beginning of the huge page to store the
@@ -1039,7 +1040,6 @@ int __weak alloc_bootmem_huge_page(struc
m = addr;
goto found;
}
- hstate_next_node_to_alloc(h);
nr_nodes--;
}
return 0;
--
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