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| author | David Decotigny <decot@googlers.com> | 2013-01-11 14:31:36 -0800 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2013-01-11 14:54:54 -0800 |
| commit | 896f97ea95c1d29c0520ee0766b66b7f64cb967c (patch) | |
| tree | 9898ba669c2348294452fcfd5b7b81fe04cb072f /include/linux/cpu_rmap.h | |
| parent | 254adaa465c40151df11fc1f88f93e6e86eb61d4 (diff) | |
| download | lwn-896f97ea95c1d29c0520ee0766b66b7f64cb967c.tar.gz lwn-896f97ea95c1d29c0520ee0766b66b7f64cb967c.zip | |
lib: cpu_rmap: avoid flushing all workqueues
In some cases, free_irq_cpu_rmap() is called while holding a lock (eg
rtnl). This can lead to deadlocks, because it invokes
flush_scheduled_work() which ends up waiting for whole system workqueue
to flush, but some pending works might try to acquire the lock we are
already holding.
This commit uses reference-counting to replace
irq_run_affinity_notifiers(). It also removes
irq_run_affinity_notifiers() altogether.
[akpm@linux-foundation.org: eliminate free_cpu_rmap, rename cpu_rmap_reclaim() to cpu_rmap_release(), propagate kref_put() retval from cpu_rmap_put()]
Signed-off-by: David Decotigny <decot@googlers.com>
Reviewed-by: Ben Hutchings <bhutchings@solarflare.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Or Gerlitz <ogerlitz@mellanox.com>
Acked-by: Amir Vadai <amirv@mellanox.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include/linux/cpu_rmap.h')
| -rw-r--r-- | include/linux/cpu_rmap.h | 13 |
1 files changed, 4 insertions, 9 deletions
diff --git a/include/linux/cpu_rmap.h b/include/linux/cpu_rmap.h index ac3bbb5b9502..1739510d8994 100644 --- a/include/linux/cpu_rmap.h +++ b/include/linux/cpu_rmap.h @@ -13,9 +13,11 @@ #include <linux/cpumask.h> #include <linux/gfp.h> #include <linux/slab.h> +#include <linux/kref.h> /** * struct cpu_rmap - CPU affinity reverse-map + * @refcount: kref for object * @size: Number of objects to be reverse-mapped * @used: Number of objects added * @obj: Pointer to array of object pointers @@ -23,6 +25,7 @@ * based on affinity masks */ struct cpu_rmap { + struct kref refcount; u16 size, used; void **obj; struct { @@ -33,15 +36,7 @@ struct cpu_rmap { #define CPU_RMAP_DIST_INF 0xffff extern struct cpu_rmap *alloc_cpu_rmap(unsigned int size, gfp_t flags); - -/** - * free_cpu_rmap - free CPU affinity reverse-map - * @rmap: Reverse-map allocated with alloc_cpu_rmap(), or %NULL - */ -static inline void free_cpu_rmap(struct cpu_rmap *rmap) -{ - kfree(rmap); -} +extern int cpu_rmap_put(struct cpu_rmap *rmap); extern int cpu_rmap_add(struct cpu_rmap *rmap, void *obj); extern int cpu_rmap_update(struct cpu_rmap *rmap, u16 index, |