From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx191.postini.com [74.125.245.191]) by kanga.kvack.org (Postfix) with SMTP id 0ED886B0099 for ; Sun, 8 Jul 2012 19:01:47 -0400 (EDT) Received: by pbbrp2 with SMTP id rp2so22064885pbb.14 for ; Sun, 08 Jul 2012 16:01:46 -0700 (PDT) Date: Sun, 8 Jul 2012 16:01:44 -0700 (PDT) From: David Rientjes Subject: Re: WARNING: __GFP_FS allocations with IRQs disabled (kmemcheck_alloc_shadow) In-Reply-To: Message-ID: References: <20120708040009.GA8363@localhost> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-linux-mm@kvack.org List-ID: To: JoonSoo Kim Cc: Fengguang Wu , Vegard Nossum , Christoph Lameter , Pekka Enberg , Rus , Ben Hutchings , Steven Rostedt , linux-mm@kvack.org, linux-kernel@vger.kernel.org On Mon, 9 Jul 2012, JoonSoo Kim wrote: > diff --git a/mm/slub.c b/mm/slub.c > index 8c691fa..5d41cad 100644 > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -1324,8 +1324,14 @@ static struct page *allocate_slab(struct > kmem_cache *s, gfp_t flags, int node) > && !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) { > int pages = 1 << oo_order(oo); > > + if (flags & __GFP_WAIT) > + local_irq_enable(); > + > kmemcheck_alloc_shadow(page, oo_order(oo), flags, node); > > + if (flags & __GFP_WAIT) > + local_irq_disable(); > + > /* > * Objects from caches that have a constructor don't get > * cleared when they're allocated, so we need to do it here. This patch is suboptimal when the branch is taken since you just disabled irqs and now are immediately reenabling them and then disabling them again. (And your patch is also whitespace damaged, has no changelog, and isn't signed off so it can't be applied.) The correct fix is what I proposed at http://marc.info/?l=linux-kernel&m=133754837703630 and was awaiting testing. If Rus, Steven, or Fengguang could test this then we could add it as a stable backport as well. -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org