[merged mm-stable] mm-replace-custom-bad-page-map-ratelimiting-logic.patch removed from -mm tree

[merged mm-stable] mm-replace-custom-bad-page-map-ratelimiting-logic.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm: replace custom bad page map ratelimiting logic
has been removed from the -mm tree.  Its filename was
     mm-replace-custom-bad-page-map-ratelimiting-logic.patch

This patch was dropped because it was merged into the mm-stable branch
of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

------------------------------------------------------
From: Pedro Falcato <pfalcato@suse.de>
Subject: mm: replace custom bad page map ratelimiting logic
Date: Tue, 11 Aug 2026 18:21:55 +0100

Patch series "mm: replace custom ratelimiting logic".

The kernel has a perfectly cromulent and mostly-equivalent variant in
lib/ratelimit.c that can be used.


This patch (of 2):

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 "print_bad_page_map: %d callbacks suppressed\n", ...

But that should be fine enough.

Link: https://lore.kernel.org/20260811172156.356053-1-pfalcato@suse.de
Link: https://lore.kernel.org/20260811172156.356053-2-pfalcato@suse.de
Signed-off-by: Pedro Falcato <pfalcato@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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>
---

 mm/memory.c |   30 +++---------------------------
 1 file changed, 3 insertions(+), 27 deletions(-)

--- a/mm/memory.c~mm-replace-custom-bad-page-map-ratelimiting-logic
+++ a/mm/memory.c
@@ -492,32 +492,8 @@ static inline void add_mm_rss_vec(struct
 			add_mm_counter(mm, i, rss[i]);
 }
 
-static bool is_bad_page_map_ratelimited(void)
-{
-	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++;
-			return true;
-		}
-		if (nr_unshown) {
-			pr_alert("BUG: Bad page map: %lu messages suppressed\n",
-				 nr_unshown);
-			nr_unshown = 0;
-		}
-		nr_shown = 0;
-	}
-	if (nr_shown++ == 0)
-		resume = jiffies + 60 * HZ;
-	return false;
-}
+/* Allow a burst of 60 bad page map reports per minute. */
+static DEFINE_RATELIMIT_STATE(bad_page_map_ratelimit, 60 * HZ, 60);
 
 static void ptval_bytes_to_hex_str(char *buf, size_t buf_size, const void *entry, size_t entry_size)
 {
@@ -633,7 +609,7 @@ static void print_bad_page_map(struct vm
 	char entry_str[PTVAL_STR_MAX];
 	pgoff_t index, anon_index;
 
-	if (is_bad_page_map_ratelimited())
+	if (!__ratelimit(&bad_page_map_ratelimit))
 		return;
 
 	mapping = vma->vm_file ? vma->vm_file->f_mapping : NULL;
_

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