Messages in this thread Patch in this message | | | Subject | Re: [patch] mm, slub: ensure irqs are enabled for kmemcheck | From | Steven Rostedt <> | Date | Mon, 09 Jul 2012 09:46:33 -0400 |
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On Mon, 2012-07-09 at 03:36 -0700, David Rientjes wrote: > kmemcheck_alloc_shadow() requires irqs to be enabled, so wait to disable > them until after its called for __GFP_WAIT allocations. > > This fixes a warning for such allocations: > > WARNING: at kernel/lockdep.c:2739 lockdep_trace_alloc+0x14e/0x1c0() > > Cc: stable@vger.kernel.org [3.1+] > Acked-by: Fengguang Wu <fengguang.wu@intel.com> > Tested-by: Fengguang Wu <fengguang.wu@intel.com> > Signed-off-by: David Rientjes <rientjes@google.com> > --- > mm/slub.c | 13 ++++++------- > 1 file changed, 6 insertions(+), 7 deletions(-) > > diff --git a/mm/slub.c b/mm/slub.c > --- a/mm/slub.c > +++ b/mm/slub.c > @@ -1314,13 +1314,7 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) > stat(s, ORDER_FALLBACK); > } > > - if (flags & __GFP_WAIT) > - local_irq_disable(); > - > - if (!page) > - return NULL; > - > - if (kmemcheck_enabled > + if (page && kmemcheck_enabled
One micro-optimization nit...
If kmemcheck_enabled is mostly false, and page is mostly true, wouldn't it be better to swap the two?
if (kmemcheck_enabled && page
Then the first check would just short-circuit out and we don't do the double check.
Otherwise it looks good.
Acked-by: Steven Rostedt <rostedt@goodmis.org>
-- Steve
> && !(s->flags & (SLAB_NOTRACK | DEBUG_DEFAULT_FLAGS))) { > int pages = 1 << oo_order(oo); > > @@ -1336,6 +1330,11 @@ static struct page *allocate_slab(struct kmem_cache *s, gfp_t flags, int node) > kmemcheck_mark_unallocated_pages(page, pages); > } > > + if (flags & __GFP_WAIT) > + local_irq_disable(); > + if (!page) > + return NULL; > + > page->objects = oo_objects(oo); > mod_zone_page_state(page_zone(page), > (s->flags & SLAB_RECLAIM_ACCOUNT) ?
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