From 896f97ea95c1d29c0520ee0766b66b7f64cb967c Mon Sep 17 00:00:00 2001 From: David Decotigny Date: Fri, 11 Jan 2013 14:31:36 -0800 Subject: 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 Reviewed-by: Ben Hutchings Acked-by: Eric Dumazet Reviewed-by: Josh Triplett Cc: "David S. Miller" Cc: Or Gerlitz Acked-by: Amir Vadai Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- include/linux/cpu_rmap.h | 13 ++++--------- include/linux/interrupt.h | 5 ----- 2 files changed, 4 insertions(+), 14 deletions(-) (limited to 'include') diff --git a/include/linux/cpu_rmap.h b/include/linux/cpu_rmap.h index ac3bbb5b950..1739510d899 100644 --- a/include/linux/cpu_rmap.h +++ b/include/linux/cpu_rmap.h @@ -13,9 +13,11 @@ #include #include #include +#include /** * 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, diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 5e4e6170f43..5fa5afeeb75 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -268,11 +268,6 @@ struct irq_affinity_notify { extern int irq_set_affinity_notifier(unsigned int irq, struct irq_affinity_notify *notify); -static inline void irq_run_affinity_notifiers(void) -{ - flush_scheduled_work(); -} - #else /* CONFIG_SMP */ static inline int irq_set_affinity(unsigned int irq, const struct cpumask *m) -- cgit v1.2.3-18-g5258