Commit 54114994 authored by Akinobu Mita's avatar Akinobu Mita Committed by Linus Torvalds

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: default avatarAkinobu Mita <akinobu.mita@gmail.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent 203a2935
......@@ -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),
......
......@@ -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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