Re: WARNING: __GFP_FS allocations with IRQs disabled (kmemcheck_alloc_shadow)
From: David Rientjes <rientjes@google.com>
Date: 2012-07-08 23:01:47
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On Mon, 9 Jul 2012, JoonSoo Kim wrote:
quoted hunk ↗ jump to hunk
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(structkmem_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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a>