diff options
| -rw-r--r-- | mm/slub.c | 49 |
1 files changed, 45 insertions, 4 deletions
diff --git a/mm/slub.c b/mm/slub.c index 78c488202f7..7836b45ea1f 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -354,6 +354,42 @@ static __always_inline void slab_unlock(struct page *page) __bit_spin_unlock(PG_locked, &page->flags); } +/* Interrupts must be disabled (for the fallback code to work right) */ +static inline bool __cmpxchg_double_slab(struct kmem_cache *s, struct page *page, + void *freelist_old, unsigned long counters_old, + void *freelist_new, unsigned long counters_new, + const char *n) +{ + VM_BUG_ON(!irqs_disabled()); +#ifdef CONFIG_CMPXCHG_DOUBLE + if (s->flags & __CMPXCHG_DOUBLE) { + if (cmpxchg_double(&page->freelist, + freelist_old, counters_old, + freelist_new, counters_new)) + return 1; + } else +#endif + { + slab_lock(page); + if (page->freelist == freelist_old && page->counters == counters_old) { + page->freelist = freelist_new; + page->counters = counters_new; + slab_unlock(page); + return 1; + } + slab_unlock(page); + } + + cpu_relax(); + stat(s, CMPXCHG_DOUBLE_FAIL); + +#ifdef SLUB_DEBUG_CMPXCHG + printk(KERN_INFO "%s %s: cmpxchg double redo ", n, s->name); +#endif + + return 0; +} + static inline bool cmpxchg_double_slab(struct kmem_cache *s, struct page *page, void *freelist_old, unsigned long counters_old, void *freelist_new, unsigned long counters_new, @@ -368,14 +404,19 @@ static inline bool cmpxchg_double_slab(struct kmem_cache *s, struct page *page, } else #endif { + unsigned long flags; + + local_irq_save(flags); slab_lock(page); if (page->freelist == freelist_old && page->counters == counters_old) { page->freelist = freelist_new; page->counters = counters_new; slab_unlock(page); + local_irq_restore(flags); return 1; } slab_unlock(page); + local_irq_restore(flags); } cpu_relax(); @@ -1471,7 +1512,7 @@ static inline int acquire_slab(struct kmem_cache *s, VM_BUG_ON(new.frozen); new.frozen = 1; - } while (!cmpxchg_double_slab(s, page, + } while (!__cmpxchg_double_slab(s, page, freelist, counters, NULL, new.counters, "lock and freeze")); @@ -1709,7 +1750,7 @@ static void deactivate_slab(struct kmem_cache *s, struct kmem_cache_cpu *c) new.inuse--; VM_BUG_ON(!new.frozen); - } while (!cmpxchg_double_slab(s, page, + } while (!__cmpxchg_double_slab(s, page, prior, counters, freelist, new.counters, "drain percpu freelist")); @@ -1798,7 +1839,7 @@ redo: } l = m; - if (!cmpxchg_double_slab(s, page, + if (!__cmpxchg_double_slab(s, page, old.freelist, old.counters, new.freelist, new.counters, "unfreezing slab")) @@ -1992,7 +2033,7 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node, new.inuse = page->objects; new.frozen = object != NULL; - } while (!cmpxchg_double_slab(s, page, + } while (!__cmpxchg_double_slab(s, page, object, counters, NULL, new.counters, "__slab_alloc")); |