[merged mm-stable] mm-kmemleak-skip-the-remaining-scan-phases-when-interrupted.patch removed from -mm tree

[merged mm-stable] mm-kmemleak-skip-the-remaining-scan-phases-when-interrupted.patch removed from -mm tree

[Andrew Morton]

The quilt patch titled
     Subject: mm/kmemleak: skip the remaining scan phases when interrupted
has been removed from the -mm tree.  Its filename was
     mm-kmemleak-skip-the-remaining-scan-phases-when-interrupted.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: Breno Leitao <leitao@debian.org>
Subject: mm/kmemleak: skip the remaining scan phases when interrupted
Date: Fri, 26 Jun 2026 10:56:23 -0700

kmemleak_scan() scans the per-cpu sections, the struct page ranges and the
task stacks in sequence.  Each loop now bails out once scan_block()
reports the scan was interrupted, but the later phases are still entered
and only bail on their first scan_block() call.

Jump straight to the gray list scan once a phase reports an interrupted
scan, so the remaining scan phases are not entered at all.  This does not
change the scan results, it only avoids the pointless re-entry.

Link: https://lore.kernel.org/20260626-kmemleak_improve-v1-1-d40c7616f64f@debian.org
Signed-off-by: Breno Leitao <leitao@debian.org>
Suggested-by: Oleg Nesterov <oleg@redhat.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
---

 mm/kmemleak.c |    7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

--- a/mm/kmemleak.c~mm-kmemleak-skip-the-remaining-scan-phases-when-interrupted
+++ a/mm/kmemleak.c
@@ -1851,6 +1851,7 @@ static void kmemleak_scan(void)
 	int __maybe_unused i;
 	struct xarray dedup;
 	int new_leaks = 0;
+	int stop = 0;
 
 	jiffies_last_scan = jiffies;
 
@@ -1897,7 +1898,7 @@ static void kmemleak_scan(void)
 	for_each_possible_cpu(i) {
 		if (scan_large_block(__per_cpu_start + per_cpu_offset(i),
 				     __per_cpu_end + per_cpu_offset(i)))
-			break;
+			goto scan_gray;
 	}
 #endif
 
@@ -1909,7 +1910,6 @@ static void kmemleak_scan(void)
 		unsigned long start_pfn = zone->zone_start_pfn;
 		unsigned long end_pfn = zone_end_pfn(zone);
 		unsigned long pfn;
-		int stop = 0;
 
 		for (pfn = start_pfn; pfn < end_pfn; pfn++) {
 			struct page *page = pfn_to_online_page(pfn);
@@ -1934,6 +1934,8 @@ static void kmemleak_scan(void)
 			break;
 	}
 	put_online_mems();
+	if (stop)
+		goto scan_gray;
 
 	/*
 	 * Scanning the task stacks (may introduce false negatives).
@@ -1945,6 +1947,7 @@ static void kmemleak_scan(void)
 	 * Scan the objects already referenced from the sections scanned
 	 * above.
 	 */
+scan_gray:
 	scan_gray_list();
 
 	/*
_

Patches currently in -mm which might be from leitao@debian.org are

mm-memory-failure-drop-dead-error_states-entry-for-reserved-pages.patch
mm-memory-failure-surface-unhandlable-kernel-pages-as-enotrecoverable.patch
mm-memory-failure-report-mf_msg_kernel-for-unrecoverable-kernel-pages.patch
mm-memory-failure-add-panic-option-for-unrecoverable-pages.patch
documentation-document-panic_on_unrecoverable_memory_failure-sysctl.patch
radix-tree-fix-kmemleak-false-positives-on-tree-head-reassignment.patch
mm-kmemleak-report-leaks-only-after-n-consecutive-unreferenced-scans.patch
mm-kmemleak-factor-leak-confirmation-into-a-helper.patch
selftests-mm-test-kmemleaks-n-consecutive-scan-leak-confirmation.patch
mm-kmemleak-report-rcu-tasks-quiescent-states-during-the-scan.patch
mm-migrate-report-rcu-tasks-quiescent-states-in-migrate_pages_batch.patch