Re: [PATCH 6.6.y] mm/page_alloc: fix memory accept before watermarks gets initialized

[Sasha Levin <sashal@kernel.org>]

[ Sasha's backport helper bot ]

Hi,

Summary of potential issues:
⚠️ Found matching upstream commit but patch is missing proper reference to it

Found matching upstream commit: 800f1059c99e2b39899bdc67a7593a7bea6375d8

Status in newer kernel trees:
6.13.y | Present (different SHA1: 18c31f7ee240)
6.12.y | Present (different SHA1: f4bc2f91e6f5)

Note: The patch differs from the upstream commit:
---
1:  800f1059c99e2 ! 1:  48ab092457a25 mm/page_alloc: fix memory accept before watermarks gets initialized
    @@ Commit message
         Cc: Thomas Lendacky <thomas.lendacky@amd.com>
         Cc: <stable@vger.kernel.org>    [6.5+]
         Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
    +    (cherry picked from commit 800f1059c99e2b39899bdc67a7593a7bea6375d8)
    +    Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com>
     
      ## mm/page_alloc.c ##
    -@@ mm/page_alloc.c: static inline bool has_unaccepted_memory(void)
    +@@ mm/page_alloc.c: static bool try_to_accept_memory_one(struct zone *zone)
      
      static bool cond_accept_memory(struct zone *zone, unsigned int order)
      {
    @@ mm/page_alloc.c: static bool cond_accept_memory(struct zone *zone, unsigned int
      	if (list_empty(&zone->unaccepted_pages))
      		return false;
      
    -+	wmark = promo_wmark_pages(zone);
    ++	wmark = high_wmark_pages(zone);
     +
     +	/*
     +	 * Watermarks have not been initialized yet.
    @@ mm/page_alloc.c: static bool cond_accept_memory(struct zone *zone, unsigned int
     +	if (!wmark)
     +		return try_to_accept_memory_one(zone);
     +
    - 	/* How much to accept to get to promo watermark? */
    --	to_accept = promo_wmark_pages(zone) -
    + 	/* How much to accept to get to high watermark? */
    +-	to_accept = high_wmark_pages(zone) -
     +	to_accept = wmark -
      		    (zone_page_state(zone, NR_FREE_PAGES) -
      		    __zone_watermark_unusable_free(zone, order, 0) -
---

Results of testing on various branches:

| Branch                    | Patch Apply | Build Test |
|---------------------------|-------------|------------|
| stable/linux-6.6.y        |  Success    |  Success   |