The quilt patch titled
Subject: mm: fix missing handler for __GFP_NOWARN
has been removed from the -mm tree. Its filename was
mm-fix-missing-handler-for-__gfp_nowarn.patch
This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm
------------------------------------------------------
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.
But for some warnings that report usage problems, we don't deal with them.
If such warnings are printed, then we should fix the usage problems.
Such as the following case:
WARN_ON_ONCE((gfp_flags & __GFP_NOFAIL) && (order > 1));
[zhengqi.arch@xxxxxxxxxxxxx: v2]
Link: https://lkml.kernel.org/r/20220511061951.1114-1-zhengqi.arch@xxxxxxxxxxxxx
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 | 15 +++++++++++++++
mm/page_alloc.c | 18 ++++++++++--------
5 files changed, 33 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 +35,21 @@ struct folio_batch;
/* Do not use these with a slab allocator */
#define GFP_SLAB_BUG_MASK (__GFP_DMA32|__GFP_HIGHMEM|~__GFP_BITS_MASK)
+/*
+ * Different from WARN_ON_ONCE(), no warning will be issued
+ * when we specify __GFP_NOWARN.
+ */
+#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
@@ -3786,6 +3786,9 @@ 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);
}
@@ -4334,7 +4337,8 @@ __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;
/*
@@ -5108,7 +5112,7 @@ 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;
/*
@@ -5116,7 +5120,7 @@ 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
@@ -5124,7 +5128,7 @@ 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
@@ -5370,10 +5374,8 @@ 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;
/*
@@ -9025,7 +9027,7 @@ int __alloc_contig_migrate_range(struct
lru_cache_enable();
if (ret < 0) {
- if (ret == -EBUSY)
+ if (!(cc->gfp_mask & __GFP_NOWARN) && ret == -EBUSY)
alloc_contig_dump_pages(&cc->migratepages);
putback_movable_pages(&cc->migratepages);
return ret;
_
Patches currently in -mm which might be from zhengqi.arch@xxxxxxxxxxxxx are
