896f97ea95
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>
72 lines
1.9 KiB
C
72 lines
1.9 KiB
C
#ifndef __LINUX_CPU_RMAP_H
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#define __LINUX_CPU_RMAP_H
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/*
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* cpu_rmap.c: CPU affinity reverse-map support
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* Copyright 2011 Solarflare Communications Inc.
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 as published
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* by the Free Software Foundation, incorporated herein by reference.
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*/
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#include <linux/cpumask.h>
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#include <linux/gfp.h>
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#include <linux/slab.h>
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#include <linux/kref.h>
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/**
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* struct cpu_rmap - CPU affinity reverse-map
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* @refcount: kref for object
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* @size: Number of objects to be reverse-mapped
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* @used: Number of objects added
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* @obj: Pointer to array of object pointers
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* @near: For each CPU, the index and distance to the nearest object,
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* based on affinity masks
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*/
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struct cpu_rmap {
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struct kref refcount;
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u16 size, used;
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void **obj;
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struct {
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u16 index;
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u16 dist;
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} near[0];
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};
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#define CPU_RMAP_DIST_INF 0xffff
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extern struct cpu_rmap *alloc_cpu_rmap(unsigned int size, gfp_t flags);
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extern int cpu_rmap_put(struct cpu_rmap *rmap);
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extern int cpu_rmap_add(struct cpu_rmap *rmap, void *obj);
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extern int cpu_rmap_update(struct cpu_rmap *rmap, u16 index,
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const struct cpumask *affinity);
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static inline u16 cpu_rmap_lookup_index(struct cpu_rmap *rmap, unsigned int cpu)
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{
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return rmap->near[cpu].index;
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}
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static inline void *cpu_rmap_lookup_obj(struct cpu_rmap *rmap, unsigned int cpu)
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{
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return rmap->obj[rmap->near[cpu].index];
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}
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#ifdef CONFIG_GENERIC_HARDIRQS
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/**
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* alloc_irq_cpu_rmap - allocate CPU affinity reverse-map for IRQs
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* @size: Number of objects to be mapped
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*
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* Must be called in process context.
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*/
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static inline struct cpu_rmap *alloc_irq_cpu_rmap(unsigned int size)
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{
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return alloc_cpu_rmap(size, GFP_KERNEL);
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}
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extern void free_irq_cpu_rmap(struct cpu_rmap *rmap);
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extern int irq_cpu_rmap_add(struct cpu_rmap *rmap, int irq);
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#endif
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#endif /* __LINUX_CPU_RMAP_H */
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