lkml.org 
[lkml]   [2006]   [Sep]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
Subject[patch 3/8] fault-injection capability for kmalloc
This patch provides fault-injection capability for kmalloc.

Boot option:

failslab=<interval>,<probability>,<space>,<times>

<interval> -- specifies the interval of failures.

<probability> -- specifies how often it should fail in percent.

<space> -- specifies the size of free space where memory can be
allocated safely in bytes.

<times> -- specifies how many times failures may happen at most.

Example:

failslab=10,100,0,-1

slab allocation (kmalloc(), kmem_cache_alloc(),..) fails once per 10 times.

Cc: Pekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: Akinobu Mita <mita@miraclelinux.com>

include/linux/fault-inject.h | 4 ++++
lib/Kconfig.debug | 7 +++++++
mm/slab.c | 34 ++++++++++++++++++++++++++++++++++
3 files changed, 45 insertions(+)
Index: work-shouldfail/mm/slab.c
===================================================================
--- work-shouldfail.orig/mm/slab.c
+++ work-shouldfail/mm/slab.c
@@ -108,6 +108,7 @@
#include <linux/mempolicy.h>
#include <linux/mutex.h>
#include <linux/rtmutex.h>
+#include <linux/fault-inject.h>

#include <asm/uaccess.h>
#include <asm/cacheflush.h>
@@ -2963,11 +2964,44 @@ static void *cache_alloc_debugcheck_afte
#define cache_alloc_debugcheck_after(a,b,objp,d) (objp)
#endif

+#ifdef CONFIG_FAILSLAB
+
+static DEFINE_FAULT_ATTR(failslab_attr);
+
+static int __init setup_failslab(char *str)
+{
+ should_fail_srandom(jiffies);
+ return setup_fault_attr(&failslab_attr, str);
+}
+__setup("failslab=", setup_failslab);
+
+struct fault_attr *failslab = &failslab_attr;
+EXPORT_SYMBOL_GPL(failslab);
+
+static int should_failslab(struct kmem_cache *cachep, gfp_t flags)
+{
+ if ((flags & __GFP_NOFAIL) || cachep == &cache_cache)
+ return 0;
+ return should_fail(failslab, obj_size(cachep));
+}
+
+#else
+
+static inline int should_failslab(struct kmem_cache *cachep, gfp_t flags)
+{
+ return 0;
+}
+
+#endif
+
static inline void *____cache_alloc(struct kmem_cache *cachep, gfp_t flags)
{
void *objp;
struct array_cache *ac;

+ if (should_failslab(cachep, flags))
+ return NULL;
+
#ifdef CONFIG_NUMA
if (unlikely(current->flags & (PF_SPREAD_SLAB | PF_MEMPOLICY))) {
objp = alternate_node_alloc(cachep, flags);
Index: work-shouldfail/lib/Kconfig.debug
===================================================================
--- work-shouldfail.orig/lib/Kconfig.debug
+++ work-shouldfail/lib/Kconfig.debug
@@ -372,3 +372,10 @@ config RCU_TORTURE_TEST
config FAULT_INJECTION
bool

+config FAILSLAB
+ bool "fault-injection capabilitiy for kmalloc"
+ depends on DEBUG_KERNEL
+ select FAULT_INJECTION
+ help
+ This option provides fault-injection capabilitiy for kmalloc.
+
Index: work-shouldfail/include/linux/fault-inject.h
===================================================================
--- work-shouldfail.orig/include/linux/fault-inject.h
+++ work-shouldfail/include/linux/fault-inject.h
@@ -36,6 +36,10 @@ int setup_fault_attr(struct fault_attr *
void should_fail_srandom(unsigned long entropy);
int should_fail(struct fault_attr *attr, ssize_t size);

+#ifdef CONFIG_FAILSLAB
+extern struct fault_attr *failslab;
+#endif
+
#endif /* CONFIG_FAULT_INJECTION */

#endif /* _LINUX_FAULT_INJECT_H */
--
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-09-14 12:25    [from the cache]
©2003-2014 Jasper Spaans. hosted at Digital Ocean