The patch titled
Subject: mm/page_alloc.c: allow error injection
has been added to the -mm tree. Its filename is
mm-page_allocc-allow-error-injection.patch
This patch should soon appear at
http://ozlabs.org/~akpm/mmots/broken-out/mm-page_allocc-allow-error-injection.patch
and later at
http://ozlabs.org/~akpm/mmotm/broken-out/mm-page_allocc-allow-error-injection.patch
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------------------------------------------------------
From: Benjamin Poirier <bpoirier@xxxxxxxx>
Subject: mm/page_alloc.c: allow error injection
Model call chain after should_failslab(). Likewise, we can now use a
kprobe to override the return value of should_fail_alloc_page() and inject
allocation failures into alloc_page*().
This will allow injecting allocation failures using the BCC tools even
without building kernel with CONFIG_FAIL_PAGE_ALLOC and booting it with a
fail_page_alloc= parameter, which incurs some overhead even when failures
are not being injected. On the other hand, this patch adds an
unconditional call to should_fail_alloc_page() from page allocation
hotpath. That overhead should be rather negligible with
CONFIG_FAIL_PAGE_ALLOC=n when there's no kprobe attached, though.
[vbabka@xxxxxxx: changelog addition]
Link: http://lkml.kernel.org/r/20181214074330.18917-1-bpoirier@xxxxxxxx
Signed-off-by: Benjamin Poirier <bpoirier@xxxxxxxx>
Acked-by: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Arnd Bergmann <arnd@xxxxxxxx>
Cc: Michal Hocko <mhocko@xxxxxxxx>
Cc: Pavel Tatashin <pavel.tatashin@xxxxxxxxxxxxx>
Cc: Oscar Salvador <osalvador@xxxxxxx>
Cc: Mike Rapoport <rppt@xxxxxxxxxxxxxxxxxx>
Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx>
Cc: Alexander Duyck <alexander.h.duyck@xxxxxxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/asm-generic/error-injection.h | 1 +
mm/page_alloc.c | 10 ++++++++--
2 files changed, 9 insertions(+), 2 deletions(-)
--- a/include/asm-generic/error-injection.h~mm-page_allocc-allow-error-injection
+++ a/include/asm-generic/error-injection.h
@@ -8,6 +8,7 @@ enum {
EI_ETYPE_NULL, /* Return NULL if failure */
EI_ETYPE_ERRNO, /* Return -ERRNO if failure */
EI_ETYPE_ERRNO_NULL, /* Return -ERRNO or NULL if failure */
+ EI_ETYPE_TRUE, /* Return true if failure */
};
struct error_injection_entry {
--- a/mm/page_alloc.c~mm-page_allocc-allow-error-injection
+++ a/mm/page_alloc.c
@@ -3252,7 +3252,7 @@ static int __init setup_fail_page_alloc(
}
__setup("fail_page_alloc=", setup_fail_page_alloc);
-static bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
+static bool __should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
{
if (order < fail_page_alloc.min_order)
return false;
@@ -3302,13 +3302,19 @@ late_initcall(fail_page_alloc_debugfs);
#else /* CONFIG_FAIL_PAGE_ALLOC */
-static inline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
+static inline bool __should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
{
return false;
}
#endif /* CONFIG_FAIL_PAGE_ALLOC */
+static noinline bool should_fail_alloc_page(gfp_t gfp_mask, unsigned int order)
+{
+ return __should_fail_alloc_page(gfp_mask, order);
+}
+ALLOW_ERROR_INJECTION(should_fail_alloc_page, TRUE);
+
/*
* Return true if free base pages are above 'mark'. For high-order checks it
* will return true of the order-0 watermark is reached and there is at least
_
Patches currently in -mm which might be from bpoirier@xxxxxxxx are
mm-page_allocc-allow-error-injection.patch
