[PATCH 05/10] mm: allow mempool to fall back to memalloc reserves

Peter Zijlstra
2007-08-06T10:45:44Z

[-- Attachment #1: mm-mempool_fixup.patch --]
[-- Type: text/plain, Size: 1329 bytes --]

Allow the mempool to use the memalloc reserves when all else fails and
the allocation context would otherwise allow it.

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
---
mm/mempool.c | 12 +++++++++++-
1 file changed, 11 insertions(+), 1 deletion(-)

Index: linux-2.6-2/mm/mempool.c
===================================================================
--- linux-2.6-2.orig/mm/mempool.c
+++ linux-2.6-2/mm/mempool.c
@@ -14,6 +14,7 @@
#include <linux/mempool.h>
#include <linux/blkdev.h>
#include <linux/writeback.h>
+#include "internal.h"

static void add_element(mempool_t *pool, void *element)
{
@@ -204,7 +205,7 @@ void * mempool_alloc(mempool_t *pool, gf
void *element;
unsigned long flags;
wait_queue_t wait;
- gfp_t gfp_temp;
+ gfp_t gfp_temp, gfp_orig = gfp_mask;

might_sleep_if(gfp_mask & __GFP_WAIT);

@@ -228,6 +229,15 @@ repeat_alloc:
}
spin_unlock_irqrestore(&pool->lock, flags);

+ /* if we really had right to the emergency reserves try those */
+ if (gfp_to_alloc_flags(gfp_orig) & ALLOC_NO_WATERMARKS) {
+ if (gfp_temp & __GFP_NOMEMALLOC) {
+ gfp_temp &= ~(__GFP_NOMEMALLOC|__GFP_NOWARN);
+ goto repeat_alloc;
+ } else
+ gfp_temp |= __GFP_NOMEMALLOC|__GFP_NOWARN;
+ }
+
/* We must not sleep in the GFP_ATOMIC case */
if (!(gfp_mask & __GFP_WAIT))
return NULL;

--