From 54114994f4de7e8076fc250e44501e55e19b75b5 Mon Sep 17 00:00:00 2001
From: Akinobu Mita <akinobu.mita@gmail.com>
Date: Sun, 15 Jul 2007 23:40:23 -0700
Subject: [PATCH] fault-injection: add min-order parameter to fail_page_alloc
Limiting smaller allocation failures by fault injection helps to find real
possible bugs. Because higher order allocations are likely to fail and
zero-order allocations are not likely to fail.
This patch adds min-order parameter to fail_page_alloc. It specifies the
minimum page allocation order to be injected failures.
Signed-off-by: Akinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
---
Documentation/fault-injection/fault-injection.txt | 5 +++++
mm/page_alloc.c | 12 +++++++++++-
2 files changed, 16 insertions(+), 1 deletion(-)
diff --git a/Documentation/fault-injection/fault-injection.txt b/Documentation/fault-injection/fault-injection.txt
index b7ca560b93407..36ece095ff172 100644
--- a/Documentation/fault-injection/fault-injection.txt
+++ b/Documentation/fault-injection/fault-injection.txt
@@ -103,6 +103,11 @@ configuration of fault-injection capabilities.
default is 'N', setting it to 'Y' will inject failures
only into non-sleep allocations (GFP_ATOMIC allocations).
+- /debug/fail_page_alloc/min-order:
+
+ specifies the minimum page allocation order to be injected
+ failures.
+
o Boot option
In order to inject faults while debugfs is not available (early boot time),
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 297efcf05ba40..f9e4e647d7e8d 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -900,11 +900,13 @@ static struct fail_page_alloc_attr {
u32 ignore_gfp_highmem;
u32 ignore_gfp_wait;
+ u32 min_order;
#ifdef CONFIG_FAULT_INJECTION_DEBUG_FS
struct dentry *ignore_gfp_highmem_file;
struct dentry *ignore_gfp_wait_file;
+ struct dentry *min_order_file;
#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
@@ -912,6 +914,7 @@ static struct fail_page_alloc_attr {
.attr = FAULT_ATTR_INITIALIZER,
.ignore_gfp_wait = 1,
.ignore_gfp_highmem = 1,
+ .min_order = 1,
};
static int __init setup_fail_page_alloc(char *str)
@@ -922,6 +925,8 @@ __setup("fail_page_alloc=", setup_fail_page_alloc);
static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
{
+ if (order < fail_page_alloc.min_order)
+ return 0;
if (gfp_mask & __GFP_NOFAIL)
return 0;
if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
@@ -953,12 +958,17 @@ static int __init fail_page_alloc_debugfs(void)
fail_page_alloc.ignore_gfp_highmem_file =
debugfs_create_bool("ignore-gfp-highmem", mode, dir,
&fail_page_alloc.ignore_gfp_highmem);
+ fail_page_alloc.min_order_file =
+ debugfs_create_u32("min-order", mode, dir,
+ &fail_page_alloc.min_order);
if (!fail_page_alloc.ignore_gfp_wait_file ||
- !fail_page_alloc.ignore_gfp_highmem_file) {
+ !fail_page_alloc.ignore_gfp_highmem_file ||
+ !fail_page_alloc.min_order_file) {
err = -ENOMEM;
debugfs_remove(fail_page_alloc.ignore_gfp_wait_file);
debugfs_remove(fail_page_alloc.ignore_gfp_highmem_file);
+ debugfs_remove(fail_page_alloc.min_order_file);
cleanup_fault_attr_dentries(&fail_page_alloc.attr);
}
--
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