Group short-lived and reclaimable kernel allocations

This patch marks a number of allocations that are either short-lived such as
network buffers or are reclaimable such as inode allocations.  When something
like updatedb is called, long-lived and unmovable kernel allocations tend to
be spread throughout the address space which increases fragmentation.

This patch groups these allocations together as much as possible by adding a
new MIGRATE_TYPE.  The MIGRATE_RECLAIMABLE type is for allocations that can be
reclaimed on demand, but not moved.  i.e.  they can be migrated by deleting
them and re-reading the information from elsewhere.

Signed-off-by: Mel Gorman <mel@csn.ul.ie>
Cc: Andy Whitcroft <apw@shadowen.org>
Cc: Christoph Lameter <clameter@sgi.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/mm/slub.c b/mm/slub.c
index 19d3202ca2dc..a90c4ffc9576 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1055,6 +1055,9 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node)
         if (s->flags & SLAB_CACHE_DMA)
                 flags |= SLUB_DMA;
 
+        if (s->flags & SLAB_RECLAIM_ACCOUNT)
+                flags |= __GFP_RECLAIMABLE;
+
         if (node == -1)
                 page = alloc_pages(flags, s->order);
         else