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authorPekka Enberg <penberg@cs.helsinki.fi>2009-06-12 14:03:06 +0300
committerPekka Enberg <penberg@cs.helsinki.fi>2009-06-12 18:53:33 +0300
commit7e85ee0c1d15ca5f8bff0f514f158eba1742dd87 (patch)
tree8f9c21f0df6bea88740d7dd48834ac9ffc238e93
parenteb91f1d0a531289e18f5587dc197d12a251c66a3 (diff)
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 <penberg@cs.helsinki.fi>
-rw-r--r--include/linux/gfp.h3
-rw-r--r--include/linux/slab.h2
-rw-r--r--include/linux/slob_def.h5
-rw-r--r--include/linux/slub_def.h2
-rw-r--r--init/main.c1
-rw-r--r--mm/slab.c18
-rw-r--r--mm/slub.c16
7 files changed, 47 insertions, 0 deletions
diff --git a/include/linux/gfp.h b/include/linux/gfp.h
index 0bbc15f5453..3760e7c5de0 100644
--- a/include/linux/gfp.h
+++ b/include/linux/gfp.h
@@ -85,6 +85,9 @@ struct vm_area_struct;
__GFP_NOWARN|__GFP_REPEAT|__GFP_NOFAIL|\
__GFP_NORETRY|__GFP_NOMEMALLOC)
+/* Control slab gfp mask during early boot */
+#define SLAB_GFP_BOOT_MASK __GFP_BITS_MASK & ~(__GFP_WAIT|__GFP_IO|__GFP_FS)
+
/* Control allocation constraints */
#define GFP_CONSTRAINT_MASK (__GFP_HARDWALL|__GFP_THISNODE)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 48803064ced..219b8fb4651 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -319,4 +319,6 @@ static inline void *kzalloc_node(size_t size, gfp_t flags, int node)
return kmalloc_node(size, flags | __GFP_ZERO, node);
}
+void __init kmem_cache_init_late(void);
+
#endif /* _LINUX_SLAB_H */
diff --git a/include/linux/slob_def.h b/include/linux/slob_def.h
index 0ec00b39d00..bb5368df4be 100644
--- a/include/linux/slob_def.h
+++ b/include/linux/slob_def.h
@@ -34,4 +34,9 @@ static __always_inline void *__kmalloc(size_t size, gfp_t flags)
return kmalloc(size, flags);
}
+static inline void kmem_cache_init_late(void)
+{
+ /* Nothing to do */
+}
+
#endif /* __LINUX_SLOB_DEF_H */
diff --git a/include/linux/slub_def.h b/include/linux/slub_def.h
index be5d40c43bd..4dcbc2c7149 100644
--- a/include/linux/slub_def.h
+++ b/include/linux/slub_def.h
@@ -302,4 +302,6 @@ static __always_inline void *kmalloc_node(size_t size, gfp_t flags, int node)
}
#endif
+void __init kmem_cache_init_late(void);
+
#endif /* _LINUX_SLUB_DEF_H */
diff --git a/init/main.c b/init/main.c
index b3e8f14c568..f6204f712e7 100644
--- a/init/main.c
+++ b/init/main.c
@@ -640,6 +640,7 @@ asmlinkage void __init start_kernel(void)
"enabled early\n");
early_boot_irqs_on();
local_irq_enable();
+ kmem_cache_init_late();
/*
* HACK ALERT! This is early. We're enabling the console before
diff --git a/mm/slab.c b/mm/slab.c
index cd76964b53b..453efcb1c98 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -304,6 +304,12 @@ struct kmem_list3 {
};
/*
+ * 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.
*/
#define NUM_INIT_LISTS (3 * MAX_NUMNODES)
@@ -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 3964d3ce4c1..30354bfeb43 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
*/