Messages in this thread Patch in this message | | | Date | Tue, 25 Nov 2008 00:47:33 +0200 (EET) | From | Pekka J Enberg <> | Subject | Re: [RFC PATCH] slab: __GFP_NOWARN not being propagated from mempool_alloc() |
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On Mon, 24 Nov 2008, Miklos Szeredi wrote: > We see page allocation failure warnings on the mempool_alloc() path. > See this lkml posting for example: > > http://lkml.org/lkml/2008/10/27/100 > > The cause is that on NUMA, alloc_slabmgmt() clears __GFP_NOWARN, > together with __GFP_THISNODE and __GFP_NORETRY. But AFAICS it really > only wants to clear __GFP_THISNODE. > > Does this patch looks good?
Yes, it does but looking at mm/slab.c history I think we want something like the following instead. Christoph?
P.S. First one to test it gets a fabulous prize of a Tested-by tag in the patch description! How cool is that?
Pekka
From 717b2d7bd2398e948d1dfbd2e83bd6a8403b68da Mon Sep 17 00:00:00 2001 From: Pekka Enberg <penberg@cs.helsinki.fi> Date: Tue, 25 Nov 2008 00:33:28 +0200 Subject: [PATCH] slab: remove GFP_THISNODE clearing from alloc_slabmgmt()
Commit 6cb062296f73e74768cca2f3eaf90deac54de02d ("Categorize GFP flags") left one call-site in alloc_slabmgmt() to clear GFP_THISNODE instead of GFP_CONSTRAINT_MASK. Unfortunately, that ends up clearing __GFP_NOWARN and __GFP_NORETRY as well which is not what we want. As the only caller of alloc_slabmgmt() already clears GFP_CONSTRAINT_MASK before passing local_flags to it, we can just remove the clearing of GFP_THISNODE.
This patch should fix spurious page allocation failure warnings on the mempool_alloc() path. See the following URL for an example:
http://lkml.org/lkml/2008/10/27/100
Reported-by: Miklos Szeredi <miklos@szeredi.hu> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> --- mm/slab.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/mm/slab.c b/mm/slab.c index 918f04f..98d3024 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2608,7 +2608,7 @@ static struct slab *alloc_slabmgmt(struct kmem_cache *cachep, void *objp, if (OFF_SLAB(cachep)) { /* Slab management obj is off-slab. */ slabp = kmem_cache_alloc_node(cachep->slabp_cache, - local_flags & ~GFP_THISNODE, nodeid); + local_flags, nodeid); if (!slabp) return NULL; } else { -- 1.5.6.4
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