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>
default is 'N', setting it to 'Y' will inject failures
only into non-sleep allocations (GFP_ATOMIC allocations).
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),
o Boot option
In order to inject faults while debugfs is not available (early boot time),
u32 ignore_gfp_highmem;
u32 ignore_gfp_wait;
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;
#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 */
#endif /* CONFIG_FAULT_INJECTION_DEBUG_FS */
.attr = FAULT_ATTR_INITIALIZER,
.ignore_gfp_wait = 1,
.ignore_gfp_highmem = 1,
.attr = FAULT_ATTR_INITIALIZER,
.ignore_gfp_wait = 1,
.ignore_gfp_highmem = 1,
};
static int __init setup_fail_page_alloc(char *str)
};
static int __init setup_fail_page_alloc(char *str)
static int should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
{
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))
if (gfp_mask & __GFP_NOFAIL)
return 0;
if (fail_page_alloc.ignore_gfp_highmem && (gfp_mask & __GFP_HIGHMEM))
fail_page_alloc.ignore_gfp_highmem_file =
debugfs_create_bool("ignore-gfp-highmem", mode, dir,
&fail_page_alloc.ignore_gfp_highmem);
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 ||
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);
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);
}
cleanup_fault_attr_dentries(&fail_page_alloc.attr);
}