From 7e85ee0c1d15ca5f8bff0f514f158eba1742dd87 Mon Sep 17 00:00:00 2001 From: Pekka Enberg Date: Fri, 12 Jun 2009 14:03:06 +0300 Subject: slab,slub: don't enable interrupts during early boot 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, mask out __GFP_WAIT, __GFP_IO, and __GFP_FS in the slab allocators in early boot code to avoid enabling interrupts. Signed-off-by: Pekka Enberg --- mm/slab.c | 18 ++++++++++++++++++ mm/slub.c | 16 ++++++++++++++++ 2 files changed, 34 insertions(+) (limited to 'mm') diff --git a/mm/slab.c b/mm/slab.c index cd76964b53bc..453efcb1c980 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -303,6 +303,12 @@ struct kmem_list3 { int free_touched; /* updated without locking */ }; +/* + * The slab allocator is initialized with interrupts disabled. Therefore, make + * sure early boot allocations don't accidentally enable interrupts. + */ +static gfp_t slab_gfp_mask __read_mostly = SLAB_GFP_BOOT_MASK; + /* * Need this for bootstrapping a per node allocator. */ @@ -1654,6 +1660,14 @@ void __init kmem_cache_init(void) */ } +void __init kmem_cache_init_late(void) +{ + /* + * Interrupts are enabled now so all GFP allocations are safe. + */ + slab_gfp_mask = __GFP_BITS_MASK; +} + static int __init cpucache_init(void) { int cpu; @@ -3354,6 +3368,8 @@ __cache_alloc_node(struct kmem_cache *cachep, gfp_t flags, int nodeid, unsigned long save_flags; void *ptr; + flags &= slab_gfp_mask; + lockdep_trace_alloc(flags); if (slab_should_failslab(cachep, flags)) @@ -3434,6 +3450,8 @@ __cache_alloc(struct kmem_cache *cachep, gfp_t flags, void *caller) unsigned long save_flags; void *objp; + flags &= slab_gfp_mask; + lockdep_trace_alloc(flags); if (slab_should_failslab(cachep, flags)) diff --git a/mm/slub.c b/mm/slub.c index 3964d3ce4c15..30354bfeb43d 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -178,6 +178,12 @@ static enum { SYSFS /* Sysfs up */ } slab_state = DOWN; +/* + * The slab allocator is initialized with interrupts disabled. Therefore, make + * sure early boot allocations don't accidentally enable interrupts. + */ +static gfp_t slab_gfp_mask __read_mostly = SLAB_GFP_BOOT_MASK; + /* A list of all slab caches on the system */ static DECLARE_RWSEM(slub_lock); static LIST_HEAD(slab_caches); @@ -1595,6 +1601,8 @@ static __always_inline void *slab_alloc(struct kmem_cache *s, unsigned long flags; unsigned int objsize; + gfpflags &= slab_gfp_mask; + lockdep_trace_alloc(gfpflags); might_sleep_if(gfpflags & __GFP_WAIT); @@ -3104,6 +3112,14 @@ void __init kmem_cache_init(void) nr_cpu_ids, nr_node_ids); } +void __init kmem_cache_init_late(void) +{ + /* + * Interrupts are enabled now so all GFP allocations are safe. + */ + slab_gfp_mask = __GFP_BITS_MASK; +} + /* * Find a mergeable slab cache */ -- cgit v1.2.3