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@xxxxxxxxxxxxxxx [3.1+]
> Acked-by: Fengguang Wu <fengguang.wu@xxxxxxxxx>
> Tested-by: Fengguang Wu <fengguang.wu@xxxxxxxxx>
> Signed-off-by: David Rientjes <rientjes@xxxxxxxxxx>
> ---
> 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@xxxxxxxxxxx>
-- 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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