+ kfence-skip-__gfp_thisnode-allocations-on-numa-systems.patch added to mm-hotfixes-unstable branch

[Andrew Morton <akpm@linux-foundation.org>]

The patch titled
     Subject: kfence: skip __GFP_THISNODE allocations on NUMA systems
has been added to the -mm mm-hotfixes-unstable branch.  Its filename is
     kfence-skip-__gfp_thisnode-allocations-on-numa-systems.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/kfence-skip-__gfp_thisnode-allocations-on-numa-systems.patch

This patch will later appear in the mm-hotfixes-unstable branch at
    git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

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------------------------------------------------------
From: Marco Elver <elver@google.com>
Subject: kfence: skip __GFP_THISNODE allocations on NUMA systems
Date: Fri, 24 Jan 2025 13:01:38 +0100

On NUMA systems, __GFP_THISNODE indicates that an allocation _must_ be on
a particular node, and failure to allocate on the desired node will result
in a failed allocation.

Skip __GFP_THISNODE allocations if we are running on a NUMA system, since
KFENCE can't guarantee which node its pool pages are allocated on.

Link: https://lkml.kernel.org/r/20250124120145.410066-1-elver@google.com
Fixes: 236e9f153852 ("kfence: skip all GFP_ZONEMASK allocations")
Signed-off-by: Marco Elver <elver@google.com>
Reported-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Cc: Christoph Lameter <cl@linux.com>
Cc: Alexander Potapenko <glider@google.com>
Cc: Chistoph Lameter <cl@linux.com>
Cc: Dmitriy Vyukov <dvyukov@google.com>
Cc: <stable@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/kfence/core.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/mm/kfence/core.c~kfence-skip-__gfp_thisnode-allocations-on-numa-systems
+++ a/mm/kfence/core.c
@@ -21,6 +21,7 @@
 #include <linux/log2.h>
 #include <linux/memblock.h>
 #include <linux/moduleparam.h>
+#include <linux/nodemask.h>
 #include <linux/notifier.h>
 #include <linux/panic_notifier.h>
 #include <linux/random.h>
@@ -1084,6 +1085,7 @@ void *__kfence_alloc(struct kmem_cache *
 	 * properties (e.g. reside in DMAable memory).
 	 */
 	if ((flags & GFP_ZONEMASK) ||
+	    ((flags & __GFP_THISNODE) && num_online_nodes() > 1) ||
 	    (s->flags & (SLAB_CACHE_DMA | SLAB_CACHE_DMA32))) {
 		atomic_long_inc(&counters[KFENCE_COUNTER_SKIP_INCOMPAT]);
 		return NULL;
_

Patches currently in -mm which might be from elver@google.com are

kfence-skip-__gfp_thisnode-allocations-on-numa-systems.patch