The patch titled
Subject: mm: fix missing handler for __GFP_NOWARN
has been added to the -mm mm-unstable branch. Its filename is
mm-fix-missing-handler-for-__gfp_nowarn.patch
This patch will shortly appear at
https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-fix-missing-handler-for-__gfp_nowarn.patch
This patch will later appear in the mm-unstable branch at
git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
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------------------------------------------------------
From: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Subject: mm: fix missing handler for __GFP_NOWARN
We expect no warnings to be issued when we specify __GFP_NOWARN, but
currently in paths like alloc_pages() and kmalloc(), there are still some
warnings printed, fix it.
Link: https://lkml.kernel.org/r/20220510113809.80626-1-zhengqi.arch@xxxxxxxxxxxxx
Signed-off-by: Qi Zheng <zhengqi.arch@xxxxxxxxxxxxx>
Cc: Akinobu Mita <akinobu.mita@xxxxxxxxx>
Cc: Vlastimil Babka <vbabka@xxxxxxx>
Cc: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Cc: Jiri Slaby <jirislaby@xxxxxxxxxx>
Cc: Steven Rostedt (Google) <rostedt@xxxxxxxxxxx>
Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
---
include/linux/fault-inject.h | 2 ++
lib/fault-inject.c | 3 +++
mm/failslab.c | 3 +++
mm/internal.h | 11 +++++++++++
mm/page_alloc.c | 18 ++++++++++--------
5 files changed, 29 insertions(+), 8 deletions(-)
--- a/include/linux/fault-inject.h~mm-fix-missing-handler-for-__gfp_nowarn
+++ a/include/linux/fault-inject.h
@@ -20,6 +20,7 @@ struct fault_attr {
atomic_t space;
unsigned long verbose;
bool task_filter;
+ bool no_warn;
unsigned long stacktrace_depth;
unsigned long require_start;
unsigned long require_end;
@@ -39,6 +40,7 @@ struct fault_attr {
.ratelimit_state = RATELIMIT_STATE_INIT_DISABLED, \
.verbose = 2, \
.dname = NULL, \
+ .no_warn = false, \
}
#define DECLARE_FAULT_ATTR(name) struct fault_attr name = FAULT_ATTR_INITIALIZER
--- a/lib/fault-inject.c~mm-fix-missing-handler-for-__gfp_nowarn
+++ a/lib/fault-inject.c
@@ -41,6 +41,9 @@ EXPORT_SYMBOL_GPL(setup_fault_attr);
static void fail_dump(struct fault_attr *attr)
{
+ if (attr->no_warn)
+ return;
+
if (attr->verbose > 0 && __ratelimit(&attr->ratelimit_state)) {
printk(KERN_NOTICE "FAULT_INJECTION: forcing a failure.\n"
"name %pd, interval %lu, probability %lu, "
--- a/mm/failslab.c~mm-fix-missing-handler-for-__gfp_nowarn
+++ a/mm/failslab.c
@@ -30,6 +30,9 @@ bool __should_failslab(struct kmem_cache
if (failslab.cache_filter && !(s->flags & SLAB_FAILSLAB))
return false;
+ if (gfpflags & __GFP_NOWARN)
+ failslab.attr.no_warn = true;
+
return should_fail(&failslab.attr, s->object_size);
}
--- a/mm/internal.h~mm-fix-missing-handler-for-__gfp_nowarn
+++ a/mm/internal.h
@@ -35,6 +35,17 @@ struct folio_batch;
/* Do not use these with a slab allocator */
#define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
+#define WARN_ON_ONCE_GFP(cond, gfp) ({ \
+ static bool __section(".data.once") __warned; \
+ int __ret_warn_once = !!(cond); \
+ \
+ if (unlikely(!(gfp & __GFP_NOWARN) && __ret_warn_once && !__warned)) { \
+ __warned = true; \
+ WARN_ON(1); \
+ } \
+ unlikely(__ret_warn_once); \
+})
+
void page_writeback_init(void);
static inline void *folio_raw_mapping(struct folio *folio)
--- a/mm/page_alloc.c~mm-fix-missing-handler-for-__gfp_nowarn
+++ a/mm/page_alloc.c
@@ -3712,7 +3712,7 @@ struct page *rmqueue(struct zone *prefer
* We most definitely don't want callers attempting to
* allocate greater than order-1 page units with __GFP_NOFAIL.
*/
- WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
+ WARN_ON_ONCE_GFP((gfp_flags & __GFP_NOFAIL) && (order > 1), gfp_flags);
do {
page = NULL;
@@ -3789,6 +3789,9 @@ static bool __should_fail_alloc_page(gfp
(gfp_mask & __GFP_DIRECT_RECLAIM))
return false;
+ if (gfp_mask & __GFP_NOWARN)
+ fail_page_alloc.attr.no_warn = true;
+
return should_fail(&fail_page_alloc.attr, 1 << order);
}
@@ -4337,7 +4340,8 @@ __alloc_pages_may_oom(gfp_t gfp_mask, un
*/
/* Exhausted what can be done so it's blame time */
- if (out_of_memory(&oc) || WARN_ON_ONCE(gfp_mask & __GFP_NOFAIL)) {
+ if (out_of_memory(&oc) ||
+ WARN_ON_ONCE_GFP(gfp_mask & __GFP_NOFAIL, gfp_mask)) {
*did_some_progress = 1;
/*
@@ -5103,7 +5107,7 @@ nopage:
* All existing users of the __GFP_NOFAIL are blockable, so warn
* of any new users that actually require GFP_NOWAIT
*/
- if (WARN_ON_ONCE(!can_direct_reclaim))
+ if (WARN_ON_ONCE_GFP(!can_direct_reclaim, gfp_mask))
goto fail;
/*
@@ -5111,7 +5115,7 @@ nopage:
* because we cannot reclaim anything and only can loop waiting
* for somebody to do a work for us
*/
- WARN_ON_ONCE(current->flags & PF_MEMALLOC);
+ WARN_ON_ONCE_GFP(current->flags & PF_MEMALLOC, gfp_mask);
/*
* non failing costly orders are a hard requirement which we
@@ -5119,7 +5123,7 @@ nopage:
* so that we can identify them and convert them to something
* else.
*/
- WARN_ON_ONCE(order > PAGE_ALLOC_COSTLY_ORDER);
+ WARN_ON_ONCE_GFP(order > PAGE_ALLOC_COSTLY_ORDER, gfp_mask);
/*
* Help non-failing allocations by giving them access to memory
@@ -5365,10 +5369,8 @@ struct page *__alloc_pages(gfp_t gfp, un
* There are several places where we assume that the order value is sane
* so bail out early if the request is out of bound.
*/
- if (unlikely(order >= MAX_ORDER)) {
- WARN_ON_ONCE(!(gfp & __GFP_NOWARN));
+ if (WARN_ON_ONCE_GFP(order >= MAX_ORDER, gfp))
return NULL;
- }
gfp &= gfp_allowed_mask;
/*
_
Patches currently in -mm which might be from zhengqi.arch@xxxxxxxxxxxxx are
mm-fix-missing-handler-for-__gfp_nowarn.patch
tty-fix-deadlock-caused-by-calling-printk-under-tty_port-lock.patch
