From 54114994f4de7e8076fc250e44501e55e19b75b5 Mon Sep 17 00:00:00 2001 From: Akinobu Mita 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 Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- 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 b7ca560b934..36ece095ff1 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 297efcf05ba..f9e4e647d7e 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); } -- 2.20.1