hugetlb: restore interleaving of bootmem huge pages
authorLee Schermerhorn <Lee.Schermerhorn@hp.com>
Tue, 22 Sep 2009 00:01:25 +0000 (17:01 -0700)
committerLinus Torvalds <torvalds@linux-foundation.org>
Tue, 22 Sep 2009 14:17:26 +0000 (07:17 -0700)
commit57dd28fb0513d2f772bb215f27925165e7b9ce5f
tree6ebdf5b1a336e75b156d7818273af1d78ea78ac6
parent41a25e7e67b8be33d7598ff7968b9a8b405b6567
hugetlb: restore interleaving of bootmem huge pages

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@hp.com>
Reviewed-by: Mel Gorman <mel@csn.ul.ie>
Reviewed-by: Andy Whitcroft <apw@canonical.com>
Reviewed-by: Andi Kleen <andi@firstfloor.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
mm/hugetlb.c