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authorAkinobu Mita <akinobu.mita@gmail.com>2006-12-08 02:39:45 -0800
committerLinus Torvalds <torvalds@woody.osdl.org>2006-12-08 08:29:02 -0800
commit933e312e73f8fc39652bd4d216a5393cc3a014b9 (patch)
treea2aacc2a098c3c95fe5a94fef1a2cc9751bee79b
parent8a8b6502fb669c3a0638a08955442814cedc86b1 (diff)
[PATCH] fault-injection capability for alloc_pages()
This patch provides fault-injection capability for alloc_pages() Boot option: fail_page_alloc=<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 pages. <times> -- specifies how many times failures may happen at most. Debugfs: /debug/fail_page_alloc/interval /debug/fail_page_alloc/probability /debug/fail_page_alloc/specifies /debug/fail_page_alloc/times /debug/fail_page_alloc/ignore-gfp-highmem /debug/fail_page_alloc/ignore-gfp-wait Example: fail_page_alloc=10,100,0,-1 The page allocation (alloc_pages(), ...) fails once per 10 times. Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
-rw-r--r--lib/Kconfig.debug7
-rw-r--r--mm/page_alloc.c87
2 files changed, 94 insertions, 0 deletions
diff --git a/lib/Kconfig.debug b/lib/Kconfig.debug
index c7f567a57d7..c66b7b400c9 100644
--- a/lib/Kconfig.debug
+++ b/lib/Kconfig.debug
@@ -424,6 +424,13 @@ config FAILSLAB
help
This option provides fault-injection capabilitiy for kmalloc.
+config FAIL_PAGE_ALLOC
+ bool "Fault-injection capabilitiy for alloc_pages()"
+ depends on DEBUG_KERNEL
+ select FAULT_INJECTION
+ help
+ This option provides fault-injection capabilitiy for alloc_pages().
+
config FAULT_INJECTION_DEBUG_FS
bool "Debugfs entries for fault-injection capabilities"
depends on FAULT_INJECTION && SYSFS
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 18f0e044c43..0cc8b4376e9 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -40,6 +40,7 @@
#include <linux/sort.h>
#include <linux/pfn.h>
#include <linux/backing-dev.h>
+#include <linux/fault-inject.h>
#include <asm/tlbflush.h>
#include <asm/div64.h>
@@ -892,6 +893,89 @@ failed:
#define ALLOC_HIGH 0x20 /* __GFP_HIGH set */
#define ALLOC_CPUSET 0x40 /* check for correct cpuset */
+#ifdef CONFIG_FAIL_PAGE_ALLOC
+
+static struct fail_page_alloc_attr {
+ struct fault_attr attr;
+
+ u32 ignore_gfp_highmem;
+ u32 ignore_gfp_wait;
+
+#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
+
+ struct dentry *ignore_gfp_highmem_file;
+ struct dentry *ignore_gfp_wait_file;
+
+#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
+
+} fail_page_alloc = {
+ .attr = FAULT_ATTR_INITIALIZER,
+};
+
+static int __init setup_fail_page_alloc(char *str)
+{
+ return setup_fault_attr(&fail_page_alloc.attr, str);
+}
+__setup("fail_page_alloc=", setup_fail_page_alloc);
+
+static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
+{
+ if (gfp_mask & __GFP_NOFAIL)
+ return 0;
+ if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
+ return 0;
+ if (fail_page_alloc.ignore_gfp_wait && (gfp_mask & __GFP_WAIT))
+ return 0;
+
+ return should_fail(&fail_page_alloc.attr, 1 << order);
+}
+
+#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
+
+static int __init fail_page_alloc_debugfs(void)
+{
+ mode_t mode = S_IFREG | S_IRUSR | S_IWUSR;
+ struct dentry *dir;
+ int err;
+
+ err = init_fault_attr_dentries(&fail_page_alloc.attr,
+ "fail_page_alloc");
+ if (err)
+ return err;
+ dir = fail_page_alloc.attr.dentries.dir;
+
+ fail_page_alloc.ignore_gfp_wait_file =
+ debugfs_create_bool("ignore-gfp-wait", mode, dir,
+ &fail_page_alloc.ignore_gfp_wait);
+
+ fail_page_alloc.ignore_gfp_highmem_file =
+ debugfs_create_bool("ignore-gfp-highmem", mode, dir,
+ &fail_page_alloc.ignore_gfp_highmem);
+
+ if (!fail_page_alloc.ignore_gfp_wait_file ||
+ !fail_page_alloc.ignore_gfp_highmem_file) {
+ err = -ENOMEM;
+ debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
+ debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
+ cleanup_fault_attr_dentries(&fail_page_alloc.attr);
+ }
+
+ return err;
+}
+
+late_initcall(fail_page_alloc_debugfs);
+
+#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
+
+#else /* CONFIG_FAIL_PAGE_ALLOC */
+
+static inline int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
+{
+ return 0;
+}
+
+#endif /* CONFIG_FAIL_PAGE_ALLOC */
+
/*
* Return 1 if free pages are above 'mark'. This takes into account the order
* of the allocation.
@@ -1136,6 +1220,9 @@ __alloc_pages(gfp_t gfp_mask, unsigned int order,
might_sleep_if(wait);
+ if (should_fail_alloc_page(gfp_mask, order))
+ return NULL;
+
restart:
z = zonelist->zones; /* the list of zones suitable for gfp_mask */