Subject: + mm-mempool-warn-about-__gfp_zero-usage.patch added to -mm tree
To: sebott@xxxxxxxxxxxxxxxxxx
From: akpm@xxxxxxxxxxxxxxxxxxxx
Date: Wed, 16 Apr 2014 14:23:09 -0700
The patch titled
Subject: mm/mempool: warn about __GFP_ZERO usage
has been added to the -mm tree. Its filename is
mm-mempool-warn-about-__gfp_zero-usage.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-mempool-warn-about-__gfp_zero-usage.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-mempool-warn-about-__gfp_zero-usage.patch
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------------------------------------------------------
From: Sebastian Ott <sebott@xxxxxxxxxxxxxxxxxx>
Subject: mm/mempool: warn about __GFP_ZERO usage
Memory obtained via mempool_alloc is not always zeroed even when
called with __GFP_ZERO. Add a note and VM_BUG_ON statement to make
that clear.
Signed-off-by: Sebastian Ott <sebott@xxxxxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
mm/mempool.c | 2 ++
1 file changed, 2 insertions(+)
diff -puN mm/mempool.c~mm-mempool-warn-about-__gfp_zero-usage mm/mempool.c
--- a/mm/mempool.c~mm-mempool-warn-about-__gfp_zero-usage
+++ a/mm/mempool.c
@@ -192,6 +192,7 @@ EXPORT_SYMBOL(mempool_resize);
* returns NULL. Note that due to preallocation, this function
* *never* fails when called from process contexts. (it might
* fail if called from an IRQ context.)
+ * Note: using __GFP_ZERO is not supported.
*/
void * mempool_alloc(mempool_t *pool, gfp_t gfp_mask)
{
@@ -200,6 +201,7 @@ void * mempool_alloc(mempool_t *pool, gf
wait_queue_t wait;
gfp_t gfp_temp;
+ VM_BUG_ON(gfp_mask & __GFP_ZERO);
might_sleep_if(gfp_mask & __GFP_WAIT);
gfp_mask |= __GFP_NOMEMALLOC; /* don't allocate emergency reserves */
_
Patches currently in -mm which might be from sebott@xxxxxxxxxxxxxxxxxx are
include-linux-mmdebugh-add-vm_warn_on-and-vm_warn_on_once.patch
mm-mempool-warn-about-__gfp_zero-usage.patch
mm-mempool-warn-about-__gfp_zero-usage-fix.patch
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