Messages in this thread Patch in this message | | | Date | Fri, 12 Jun 2009 12:03:22 +0300 (EEST) | From | Pekka J Enberg <> | Subject | [PATCH v2] slab,slub: ignore __GFP_WAIT if we're booting or suspending |
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From: Pekka Enberg <penberg@cs.helsinki.fi>
As explained by Benjamin Herrenschmidt:
Oh and btw, your patch alone doesn't fix powerpc, because it's missing a whole bunch of GFP_KERNEL's in the arch code... You would have to grep the entire kernel for things that check slab_is_available() and even then you'll be missing some.
For example, slab_is_available() didn't always exist, and so in the early days on powerpc, we used a mem_init_done global that is set form mem_init() (not perfect but works in practice). And we still have code using that to do the test.
Therefore, ignore __GFP_WAIT in the slab allocators if we're booting or suspending.
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org> Cc: Christoph Lameter <cl@linux-foundation.org> Cc: Nick Piggin <npiggin@suse.de> Signed-off-by: Pekka Enberg <penberg@cs.helsinki.fi> --- v1 -> v2: fix up some missing cases pointed out by BenH
mm/slab.c | 19 ++++++++++++++++++- mm/slub.c | 24 ++++++++++++++++++++++-- 2 files changed, 40 insertions(+), 3 deletions(-)
diff --git a/mm/slab.c b/mm/slab.c index f46b65d..5119c22 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -2812,6 +2812,15 @@ static int cache_grow(struct kmem_cache *cachep, offset *= cachep->colour_off; + /* + * Lets not wait if we're booting up or suspending even if the user + * asks for it. + */ + if (system_state != SYSTEM_RUNNING) + local_flags &= ~__GFP_WAIT; + + might_sleep_if(local_flags & __GFP_WAIT); + if (local_flags & __GFP_WAIT) local_irq_enable(); @@ -3073,7 +3082,6 @@ alloc_done: static inline void cache_alloc_debugcheck_before(struct kmem_cache *cachep, gfp_t flags) { - might_sleep_if(flags & __GFP_WAIT); #if DEBUG kmem_flagcheck(cachep, flags); #endif @@ -3238,6 +3246,15 @@ retry: if (!obj) { /* + * Lets not wait if we're booting up or suspending even if the user + * asks for it. + */ + if (system_state != SYSTEM_RUNNING) + local_flags &= ~__GFP_WAIT; + + might_sleep_if(local_flags & __GFP_WAIT); + + /* * This allocation will be performed within the constraints * of the current cpuset / memory policy requirements. * We may trigger various forms of reclaim on the allowed diff --git a/mm/slub.c b/mm/slub.c index 3964d3c..6387c19 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -1548,6 +1548,20 @@ new_slab: goto load_freelist; } + /* + * Lets not wait if we're booting up or suspending even if the user + * asks for it. + */ + if (system_state != SYSTEM_RUNNING) + gfpflags &= ~__GFP_WAIT; + + /* + * Now that we really know whether or not we're going to sleep or not, + * lets do our debugging checks. + */ + lockdep_trace_alloc(gfpflags); + might_sleep_if(gfpflags & __GFP_WAIT); + if (gfpflags & __GFP_WAIT) local_irq_enable(); @@ -1595,8 +1609,7 @@ static __always_inline void *slab_alloc(struct kmem_cache *s, unsigned long flags; unsigned int objsize; - lockdep_trace_alloc(gfpflags); - might_sleep_if(gfpflags & __GFP_WAIT); + lockdep_trace_alloc(gfpflags & ~__GFP_WAIT); if (should_failslab(s->objsize, gfpflags)) return NULL; @@ -2607,6 +2620,13 @@ static noinline struct kmem_cache *dma_kmalloc_cache(int index, gfp_t flags) if (s) return s; + /* + * Lets not wait if we're booting up or suspending even if the user + * asks for it. + */ + if (system_state != SYSTEM_RUNNING) + flags &= ~__GFP_WAIT; + /* Dynamically create dma cache */ if (flags & __GFP_WAIT) down_write(&slub_lock); -- 1.6.0.4
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