+ mm-page_alloc-replace-custom-bad-page-ratelimiting-logic.patch added to mm-new branch

+ mm-page_alloc-replace-custom-bad-page-ratelimiting-logic.patch added to mm-new branch

[Andrew Morton]

The patch titled
     Subject: mm/page_alloc: replace custom bad page ratelimiting logic
has been added to the -mm mm-new branch.  Its filename is
     mm-page_alloc-replace-custom-bad-page-ratelimiting-logic.patch

This patch will shortly appear at
     https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-page_alloc-replace-custom-bad-page-ratelimiting-logic.patch

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

Note, mm-new is a provisional staging ground for work-in-progress
patches, and acceptance into mm-new is a notification for others take
notice and to finish up reviews.  Please do not hesitate to respond to
review feedback and post updated versions to replace or incrementally
fixup patches in mm-new.

The mm-new branch of mm.git is not included in linux-next

If a few days of testing in mm-new is successful, the patch will me moved
into mm.git's mm-unstable branch, which is included in linux-next

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and is updated there most days

------------------------------------------------------
From: Pedro Falcato <pfalcato@suse.de>
Subject: mm/page_alloc: replace custom bad page ratelimiting logic
Date: Tue, 11 Aug 2026 18:21:56 +0100

The current logic (allow up to $BURST prints per minute) can be entirely
replaced by the generic version in lib/ratelimit.c, used around the
kernel.

Do so. The only functional difference should be that the new logs will
read something like:

KERN_WARNING "bad_page: %d callbacks suppressed\n", ...

But that should be fine enough.

Link: https://lore.kernel.org/20260811172156.356053-3-pfalcato@suse.de
Signed-off-by: Pedro Falcato <pfalcato@suse.de>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Acked-by: Zi Yan <ziy@nvidia.com>
Reviewed-by: SJ Park <sj@kernel.org>
Acked-by: David Hildenbrand (Arm) <david@kernel.org>
Reviewed-by: Lorenzo Stoakes (ARM) <ljs@kernel.org>
Acked-by: Vlastimil Babka (SUSE) <vbabka@kernel.org>
Acked-by: Mike Rapoport (Microsoft) <rppt@kernel.org>
Cc: Brendan Jackman <brendan.jackman@linux.dev>
Cc: Liam R. Howlett <liam@infradead.org>
Cc: Michal Hocko <mhocko@suse.com>
Cc: Suren Baghdasaryan <surenb@google.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/page_alloc.c |   28 +++++-----------------------
 1 file changed, 5 insertions(+), 23 deletions(-)

--- a/mm/page_alloc.c~mm-page_alloc-replace-custom-bad-page-ratelimiting-logic
+++ a/mm/page_alloc.c
@@ -613,31 +613,13 @@ static inline bool __maybe_unused bad_ra
 }
 #endif
 
+/* Allow a burst of 60 reports per minute */
+static DEFINE_RATELIMIT_STATE(bad_page_ratelimit, 60 * HZ, 60);
+
 static void bad_page(struct page *page, const char *reason)
 {
-	static unsigned long resume;
-	static unsigned long nr_shown;
-	static unsigned long nr_unshown;
-
-	/*
-	 * Allow a burst of 60 reports, then keep quiet for that minute;
-	 * or allow a steady drip of one report per second.
-	 */
-	if (nr_shown == 60) {
-		if (time_before(jiffies, resume)) {
-			nr_unshown++;
-			goto out;
-		}
-		if (nr_unshown) {
-			pr_alert(
-			      "BUG: Bad page state: %lu messages suppressed\n",
-				nr_unshown);
-			nr_unshown = 0;
-		}
-		nr_shown = 0;
-	}
-	if (nr_shown++ == 0)
-		resume = jiffies + 60 * HZ;
+	if (!__ratelimit(&bad_page_ratelimit))
+		goto out;
 
 	pr_alert("BUG: Bad page state in process %s  pfn:%05lx\n",
 		current->comm, page_to_pfn(page));
_

Patches currently in -mm which might be from pfalcato@suse.de are

x86-alternative-exclude-text-poking-against-change_page_attr.patch
mm-replace-custom-bad-page-map-ratelimiting-logic.patch
mm-page_alloc-replace-custom-bad-page-ratelimiting-logic.patch