* Ingo Molnar <[email protected]> wrote:
> * Linus Torvalds <[email protected]> wrote:
>
> > Why isn't the "on_slab_key" local to just the init_lock_keys()
> > function, and the #ifdef around it all?
>
> yeah - find updated patch below.
(find yet another update below - there were too many newlines added
after the function.)
------->
Subject: lockdep: annotate mm/slab.c
From: Arjan van de Ven <[email protected]>
mm/slab.c uses nested locking when dealing with 'off-slab'
caches, in that case it allocates the slab header from the
(on-slab) kmalloc caches. Teach the lock validator about
this by putting all on-slab caches into a separate class.
this patch has no effect on non-lockdep kernels.
Signed-off-by: Arjan van de Ven <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
---
mm/slab.c | 23 +++++++++++++++++++++++
1 file changed, 23 insertions(+)
Index: linux/mm/slab.c
===================================================================
--- linux.orig/mm/slab.c
+++ linux/mm/slab.c
@@ -674,6 +674,28 @@ static struct kmem_cache cache_cache = {
#endif
};
+/*
+ * Slab sometimes uses the kmalloc slabs to store the slab headers
+ * for other slabs "off slab".
+ * The locking for this is tricky in that it nests within the locks
+ * of all other slabs in a few places; to deal with this special
+ * locking we put on-slab caches into a separate lock-class.
+ */
+static inline void init_lock_keys(struct cache_sizes *s)
+{
+#ifdef CONFIG_LOCKDEP
+ static struct lock_class_key on_slab_key;
+ int q;
+
+ for (q = 0; q < MAX_NUMNODES; q++) {
+ if (!s->cs_cachep->nodelists[q] || OFF_SLAB(s->cs_cachep))
+ continue;
+ lockdep_set_class(&s->cs_cachep->nodelists[q]->list_lock,
+ &on_slab_key);
+ }
+#endif
+}
+
/* Guard access to the cache-chain. */
static DEFINE_MUTEX(cache_chain_mutex);
static struct list_head cache_chain;
@@ -1391,6 +1413,7 @@ void __init kmem_cache_init(void)
ARCH_KMALLOC_FLAGS|SLAB_PANIC,
NULL, NULL);
}
+ init_lock_keys(sizes);
sizes->cs_dmacachep = kmem_cache_create(names->name_dma,
sizes->cs_size,
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
