Commit 74120095 authored by Ma Wupeng's avatar Ma Wupeng Committed by Zheng Zengkai
Browse files

mm: mem_reliable: Start fallback if no suitable zone found 

hulk inclusion
category: feature
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: default avatarMa Wupeng <mawupeng1@huawei.com>
Reviewed-by: default avatartong tiangen <tongtiangen@huawei.com>
Signed-off-by: default avatarZheng Zengkai <zhengzengkai@huawei.com>
parent 573cb6d6

mm/page_alloc.c

+28 −2
Original line number Diff line number Diff line
@@ -4674,6 +4674,25 @@ 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_RELIABLE))

		return NULL;



	ac->highest_zoneidx = gfp_zone(gfp_mask & ~GFP_RELIABLE);

	ac->preferred_zoneref = first_zones_zonelist(

		ac->zonelist, ac->highest_zoneidx, ac->nodemask);

	return ac->preferred_zoneref->zone;

}



static inline void mem_reliable_fallback_slowpath(gfp_t gfp_mask,

						  struct alloc_context *ac)

{
@@ -4691,6 +4710,11 @@ 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
@@ -4740,8 +4764,10 @@ __alloc_pages_slowpath(gfp_t gfp_mask, unsigned int order, 
	 */

	ac->preferred_zoneref = first_zones_zonelist(ac->zonelist,

					ac->highest_zoneidx, ac->nodemask);

	if (!ac->preferred_zoneref->zone)

	if (!ac->preferred_zoneref->zone) {

		if (!mem_reliable_fallback_zone(gfp_mask, ac))

			goto nopage;

	}



	if (alloc_flags & ALLOC_KSWAPD)

		wake_all_kswapds(order, gfp_mask, ac);