Messages in this thread Patch in this message |  | | | From | Dmitry Monakhov <> | | Subject | [PATCH] failslab: add abitily to filter slab caches | | Date | Tue, 23 Feb 2010 16:32:40 +0300 |
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Example: echo 1 > /sys/kernel/slab/skbuff_head_cache/failslab echo 1 > /sys/kernel/debug/failslab/cache-filter Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> --- include/linux/fault-inject.h | 4 ++-- include/linux/slab.h | 4 +++- mm/failslab.c | 18 +++++++++++++++--- mm/slab.c | 2 +- mm/slub.c | 31 +++++++++++++++++++++++++++++-- 5 files changed, 50 insertions(+), 9 deletions(-) diff --git a/include/linux/fault-inject.h b/include/linux/fault-inject.h index 06ca9b2..d935647 100644 --- a/include/linux/fault-inject.h +++ b/include/linux/fault-inject.h @@ -82,9 +82,9 @@ static inline void cleanup_fault_attr_dentries(struct fault_attr *attr) #endif /* CONFIG_FAULT_INJECTION */ #ifdef CONFIG_FAILSLAB -extern bool should_failslab(size_t size, gfp_t gfpflags); +extern bool should_failslab(size_t size, gfp_t gfpflags, unsigned long c_flags); #else -static inline bool should_failslab(size_t size, gfp_t gfpflags) +static inline bool should_failslab(size_t size, gfp_t gfpflags, unsigned long f) { return false; } diff --git a/include/linux/slab.h b/include/linux/slab.h index 2da8372..9e03a81 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -70,7 +70,9 @@ #else # define SLAB_NOTRACK 0x00000000UL #endif - +#ifdef CONFIG_FAILSLAB +# define SLAB_FAILSLAB 0x02000000UL /* Fault injection filter mark */ +#endif /* The following flags affect the page allocator grouping pages by mobility */ #define SLAB_RECLAIM_ACCOUNT 0x00020000UL /* Objects are reclaimable */ #define SLAB_TEMPORARY SLAB_RECLAIM_ACCOUNT /* Objects are short-lived */ diff --git a/mm/failslab.c b/mm/failslab.c index 9339de5..bb41f98 100644 --- a/mm/failslab.c +++ b/mm/failslab.c @@ -1,18 +1,22 @@ #include <linux/fault-inject.h> #include <linux/gfp.h> +#include <linux/slab.h> static struct { struct fault_attr attr; u32 ignore_gfp_wait; + int cache_filter; #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS struct dentry *ignore_gfp_wait_file; + struct dentry *cache_filter_file; #endif } failslab = { .attr = FAULT_ATTR_INITIALIZER, .ignore_gfp_wait = 1, + .cache_filter = 0, }; -bool should_failslab(size_t size, gfp_t gfpflags) +bool should_failslab(size_t size, gfp_t gfpflags, unsigned long cache_flags) { if (gfpflags & __GFP_NOFAIL) return false; @@ -20,6 +24,9 @@ bool should_failslab(size_t size, gfp_t gfpflags) if (failslab.ignore_gfp_wait && (gfpflags & __GFP_WAIT)) return false; + if (failslab.cache_filter && !(cache_flags & SLAB_FAILSLAB)) + return false; + return should_fail(&failslab.attr, size); } @@ -30,7 +37,6 @@ static int __init setup_failslab(char *str) __setup("failslab=", setup_failslab); #ifdef CONFIG_FAULT_INJECTION_DEBUG_FS - static int __init failslab_debugfs_init(void) { mode_t mode = S_IFREG | S_IRUSR | S_IWUSR; @@ -46,8 +52,14 @@ static int __init failslab_debugfs_init(void) debugfs_create_bool("ignore-gfp-wait", mode, dir, &failslab.ignore_gfp_wait); - if (!failslab.ignore_gfp_wait_file) { + failslab.cache_filter_file = + debugfs_create_bool("cache-filter", mode, dir, + &failslab.cache_filter); + + if (!failslab.ignore_gfp_wait_file || + !failslab.cache_filter_file) { err = -ENOMEM; + debugfs_remove(failslab.cache_filter_file); debugfs_remove(failslab.ignore_gfp_wait_file); cleanup_fault_attr_dentries(&failslab.attr); } diff --git a/mm/slab.c b/mm/slab.c index 7451bda..33496b7 100644 --- a/mm/slab.c +++ b/mm/slab.c @@ -3101,7 +3101,7 @@ static bool slab_should_failslab(struct kmem_cache *cachep, gfp_t flags) if (cachep == &cache_cache) return false; - return should_failslab(obj_size(cachep), flags); + return should_failslab(obj_size(cachep), flags, cachep->flags); } static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags) diff --git a/mm/slub.c b/mm/slub.c index 8d71aaf..64114fa 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -151,7 +151,8 @@ * Set of flags that will prevent slab merging */ #define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \ - SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE) + SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \ + SLAB_FAILSLAB) #define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \ SLAB_CACHE_DMA | SLAB_NOTRACK) @@ -1020,6 +1021,11 @@ static int __init setup_slub_debug(char *str) case 't': slub_debug |= SLAB_TRACE; break; +#ifdef CONFIG_FAILSLAB + case 'a': + slub_debug |= SLAB_FAILSLAB; + break; +#endif default: printk(KERN_ERR "slub_debug option '%c' " "unknown. skipped\n", *str); @@ -1718,7 +1724,7 @@ static __always_inline void *slab_alloc(struct kmem_cache *s, lockdep_trace_alloc(gfpflags); might_sleep_if(gfpflags & __GFP_WAIT); - if (should_failslab(s->objsize, gfpflags)) + if (should_failslab(s->objsize, gfpflags, s->flags)) return NULL; local_irq_save(flags); @@ -4171,6 +4177,23 @@ static ssize_t trace_store(struct kmem_cache *s, const char *buf, } SLAB_ATTR(trace); +#ifdef CONFIG_FAILSLAB +static ssize_t failslab_show(struct kmem_cache *s, char *buf) +{ + return sprintf(buf, "%d\n", !!(s->flags & SLAB_FAILSLAB)); +} + +static ssize_t failslab_store(struct kmem_cache *s, const char *buf, + size_t length) +{ + s->flags &= ~SLAB_FAILSLAB; + if (buf[0] == '1') + s->flags |= SLAB_FAILSLAB; + return length; +} +SLAB_ATTR(failslab); +#endif + static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf) { return sprintf(buf, "%d\n", !!(s->flags & SLAB_RECLAIM_ACCOUNT)); @@ -4467,6 +4490,10 @@ static struct attribute *slab_attrs[] = { &deactivate_remote_frees_attr.attr, &order_fallback_attr.attr, #endif +#ifdef CONFIG_FAILSLAB + &failslab_attr.attr, +#endif + NULL }; -- 1.6.6
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