From f8f0da00a3695c1c8b5fc984cd6b08c87a892e3c Mon Sep 17 00:00:00 2001
From: Ma Wupeng <mawupeng1@huawei.com>
Date: Sat, 24 Sep 2022 10:05:00 +0000
Subject: [PATCH] mm: mem_reliable: Start fallback if no suitable zone found
hulk inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I4SK3S
CVE: NA
--------------------------------
For reliable memory allocation bind to nodes which do not hvve any
reliable zones, its memory allocation will fail and then warn message
will be produced at the end of __alloc_pages_slowpath().
Though this memory allocation can fallback to movable zone in
check_after_alloc() if fallback is enabled, something should be done to
prevent this pointless warn log.
To solve this problem, fallback to movable zone if no suitable zone found.
Signed-off-by: Ma Wupeng <mawupeng1@huawei.com>
Reviewed-by: Kefeng Wang <wangkefeng.wang@huawei.com>
Signed-off-by: Yongqiang Liu <liuyongqiang13@huawei.com>
---
mm/page_alloc.c | 30 ++++++++++++++++++++++++++++--
1 file changed, 28 insertions(+), 2 deletions(-)
diff --git a/mm/page_alloc.c b/mm/page_alloc.c
index 1e59761354e1..44d286286dbb 100644
--- a/mm/page_alloc.c
+++ b/mm/page_alloc.c
@@ -4272,6 +4272,25 @@ check_retry_cpuset(int cpuset_mems_cookie, struct alloc_context *ac)
}
#ifdef CONFIG_MEMORY_RELIABLE
+/*
+ * if fallback is enabled, fallback to movable zone if no dma/normal zone
+ * found
+ */
+static inline struct zone *mem_reliable_fallback_zone(gfp_t gfp_mask,
+ struct alloc_context *ac)
+{
+ if (!reliable_allow_fb_enabled())
+ return NULL;
+
+ if (!(gfp_mask & ___GFP_RELIABILITY))
+ return NULL;
+
+ ac->high_zoneidx = gfp_zone(gfp_mask & ~___GFP_RELIABILITY);
+ ac->preferred_zoneref = first_zones_zonelist(
+ ac->zonelist, ac->high_zoneidx, ac->nodemask);
+ return ac->preferred_zoneref->zone;
+}
+
static inline void mem_reliable_fallback_slowpath(gfp_t gfp_mask,
struct alloc_context *ac)
{
@@ -4290,6 +4309,11 @@ static inline void mem_reliable_fallback_slowpath(gfp_t gfp_mask,
}
}
#else
+static inline struct zone *mem_reliable_fallback_zone(gfp_t gfp_mask,
+ struct alloc_context *ac)
+{
+ return NULL;
+}
static inline void mem_reliable_fallback_slowpath(gfp_t gfp_mask,
struct alloc_context *ac) {}
#endif
@@ -4339,8 +4363,10 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order,
*/
ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,
ac->high_zoneidx, ac->nodemask);
- if (!ac->preferred_zoneref->zone)
- goto nopage;
+ if (!ac->preferred_zoneref->zone) {
+ if (!mem_reliable_fallback_zone(gfp_mask, ac))
+ goto nopage;
+ }
if (gfp_mask & __GFP_KSWAPD_RECLAIM)
wake_all_kswapds(order, gfp_mask, ac);
--
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