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authorDavid Decotigny <decot@googlers.com>2013-01-12 02:31:36 +0400
committerLinus Torvalds <torvalds@linux-foundation.org>2013-01-12 02:54:54 +0400
commit896f97ea95c1d29c0520ee0766b66b7f64cb967c (patch)
tree9898ba669c2348294452fcfd5b7b81fe04cb072f /include/linux/cpu_rmap.h
parent254adaa465c40151df11fc1f88f93e6e86eb61d4 (diff)
downloadlinux-896f97ea95c1d29c0520ee0766b66b7f64cb967c.tar.xz
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.h13
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,