From 66ff90a1b5fce45397f7643a11c33e1e92bd891e Mon Sep 17 00:00:00 2001 From: Lee Schermerhorn Date: Mon, 21 Sep 2009 17:01:04 -0700 Subject: [PATCH] hugetlb: restore interleaving of bootmem huge pages (2.6.31) Not upstream as it is fixed differently in .32 I noticed that alloc_bootmem_huge_page() will only advance to the next node on failure to allocate a huge page. 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. Andy Whitcroft countered that the existing behavior looked like Andi Kleen's original implementation and suggested that we ask him. We did and Andy replied that his intention was to interleave the allocations. So, ... This patch moves the advance of the hstate next node from which to allocate up before the test for success of the attempted allocation. This will unconditionally advance the next node from which to alloc, interleaving successful allocations over the nodes with sufficient contiguous memory, and skipping over nodes that fail the huge page allocation attempt. Note that alloc_bootmem_huge_page() will only be called for huge pages of order > MAX_ORDER. Signed-off-by: Lee Schermerhorn Reviewed-by: Andi Kleen Cc: Mel Gorman Cc: David Rientjes Cc: Adam Litke Cc: Andy Whitcroft Cc: Eric Whitney Signed-off-by: Andrew Morton Signed-off-by: Greg Kroah-Hartman --- mm/hugetlb.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/hugetlb.c b/mm/hugetlb.c index 288567442d4f..3a08c5a78dce 100644 --- a/mm/hugetlb.c +++ b/mm/hugetlb.c @@ -983,6 +983,7 @@ __attribute__((weak)) int alloc_bootmem_huge_page(struct hstate *h) NODE_DATA(h->hugetlb_next_nid), huge_page_size(h), huge_page_size(h), 0); + hstate_next_node(h); if (addr) { /* * Use the beginning of the huge page to store the @@ -993,7 +994,6 @@ __attribute__((weak)) int alloc_bootmem_huge_page(struct hstate *h) if (m) goto found; } - hstate_next_node(h); nr_nodes--; } return 0; -- 2.39.5