The patch below does not apply to the 6.6-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.6.y git checkout FETCH_HEAD git cherry-pick -x 800f1059c99e2b39899bdc67a7593a7bea6375d8 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2025032417-prior-uncooked-bf1f@gregkh' --subject-prefix 'PATCH 6.6.y' HEAD^..

Possible dependencies:

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 800f1059c99e2b39899bdc67a7593a7bea6375d8 Mon Sep 17 00:00:00 2001 From: "Kirill A. Shutemov" kirill.shutemov@linux.intel.com Date: Mon, 10 Mar 2025 10:28:55 +0200 Subject: [PATCH] mm/page_alloc: fix memory accept before watermarks gets initialized

Watermarks are initialized during the postcore initcall. Until then, all watermarks are set to zero. This causes cond_accept_memory() to incorrectly skip memory acceptance because a watermark of 0 is always met.

This can lead to a premature OOM on boot.

To ensure progress, accept one MAX_ORDER page if the watermark is zero.

Link: https://lkml.kernel.org/r/20250310082855.2587122-1-kirill.shutemov@linux.int... Fixes: dcdfdd40fa82 ("mm: Add support for unaccepted memory") Signed-off-by: Kirill A. Shutemov kirill.shutemov@linux.intel.com Tested-by: Farrah Chen farrah.chen@intel.com Reported-by: Farrah Chen farrah.chen@intel.com Acked-by: Vlastimil Babka vbabka@suse.cz Reviewed-by: Pankaj Gupta pankaj.gupta@amd.com Cc: Ashish Kalra ashish.kalra@amd.com Cc: David Hildenbrand david@redhat.com Cc: "Edgecombe, Rick P" rick.p.edgecombe@intel.com Cc: Mel Gorman mgorman@techsingularity.net Cc: "Mike Rapoport (IBM)" rppt@kernel.org Cc: Thomas Lendacky thomas.lendacky@amd.com Cc: stable@vger.kernel.org [6.5+] Signed-off-by: Andrew Morton akpm@linux-foundation.org

diff --git a/mm/page_alloc.c b/mm/page_alloc.c index 94917c729120..542d25f77be8 100644 --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -7004,7 +7004,7 @@ static inline bool has_unaccepted_memory(void)

static bool cond_accept_memory(struct zone *zone, unsigned int order) { - long to_accept; + long to_accept, wmark; bool ret = false;

if (!has_unaccepted_memory()) @@ -7013,8 +7013,18 @@ static bool cond_accept_memory(struct zone *zone, unsigned int order) if (list_empty(&zone->unaccepted_pages)) return false;

+ wmark = promo_wmark_pages(zone); + + /* + * Watermarks have not been initialized yet. + * + * Accepting one MAX_ORDER page to ensure progress. + */ + if (!wmark) + return try_to_accept_memory_one(zone); + /* How much to accept to get to promo watermark? */ - to_accept = promo_wmark_pages(zone) - + to_accept = wmark - (zone_page_state(zone, NR_FREE_PAGES) - __zone_watermark_unusable_free(zone, order, 0) - zone_page_state(zone, NR_UNACCEPTED));