From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 7CF7C4E80C4 for ; Tue, 8 Sep 2026 22:49:08 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788907750; cv=none; b=dC09VTbNpIjXo+L0ILmiVuY0sII1SM04DFlL8kN0+WJMl6g/9VyXmaUUq5YQBQIGmP7yhqjr0dNSugxOWe89yQJVbWhlHokPtR78+vNKc4qe6749nGeq8GS6UM3qH9Tv2RrgwJekVPrHspIw/t09pFEByVKv9e7b1NEwuxT3XWA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788907750; c=relaxed/simple; bh=g1EVNKdrYG7pv2nPaYzdy/dxyJLUoDc54LAF10r6/A4=; h=Date:To:From:Subject:Message-Id; b=V1aI08XobgRXQx0SGz7Qu6Aq6mSy0t49ZaA6UmSBjZspu6QvBrVBaRjsbJkjxD+tT1UJovwRqSMcu+xVnjv0yiF86CgGerY03gzQorwXUTdCMGK04oqqVsrQhdDb+f6XS3ibsImiyRkBFagdv3JnRkYFpUwVz75NVQ6V4g4xaNw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b=xttd0tG9; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="xttd0tG9" Received: by smtp.kernel.org (Postfix) with ESMTPSA id CD87F1F00A3A; Tue, 8 Sep 2026 22:49:05 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1788907745; bh=Te2IywBEIr+tGVWig4bpVAclGqIpCtdDz6RTLn6Qn6w=; h=Date:To:From:Subject; b=xttd0tG9SZ3xLmWAHzUf026o0blR/jooyCK0PhWbNaVGs8a8rLMCgsjq+L53SX3L7 +kmWw7j4ozIwbsmllHsaLuoU/TM4Dame705XKOkBYMf0ZKSoRONTNa0ObRg7J3U/hj BskyYVr9kAIqrBt2GGft/ECWBf8lMjwgZ69eL18o= Date: Tue, 08 Sep 2026 15:49:05 -0700 To: mm-commits@vger.kernel.org,kas@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + selftests-mm-cover-a-shared-source-collapse-write-race-fix.patch added to mm-new branch Message-Id: <20260908224905.CD87F1F00A3A@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: selftests-mm-cover-a-shared-source-collapse-write-race-fix has been added to the -mm mm-new branch. Its filename is selftests-mm-cover-a-shared-source-collapse-write-race-fix.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-cover-a-shared-source-collapse-write-race-fix.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 Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/process/submit-checklist.rst when testing your code *** The -mm tree is included into linux-next via various branches at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there most days ------------------------------------------------------ From: Kiryl Shutsemau (Meta) Subject: selftests-mm-cover-a-shared-source-collapse-write-race-fix Date: Tue, 8 Sep 2026 22:02:13 +0100 Sashiko flagged two issues here: - sync[0] never closed. It is fd leak; - wstatus is garbage if waitpid() fails, returning -1; Link: https://lore.kernel.org/aqB2ckEupUKnoJt_@thinkstation Signed-off-by: Kiryl Shutsemau (Meta) Signed-off-by: Andrew Morton --- tools/testing/selftests/mm/khugepaged.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) --- a/tools/testing/selftests/mm/khugepaged.c~selftests-mm-cover-a-shared-source-collapse-write-race-fix +++ a/tools/testing/selftests/mm/khugepaged.c @@ -1230,6 +1230,7 @@ static void collapse_fork_cow_race(struc close(sync[1]); if (read(sync[0], &go, 1) != 1) ksft_exit_fail_msg("child never reached the collapse\n"); + close(sync[0]); /* * Unshare one page at a time: a burst would break CoW on the whole @@ -1237,12 +1238,17 @@ static void collapse_fork_cow_race(struc */ i = 0; for (;;) { + pid_t ret; + if (i < n) ip[i * stride] = i + 0xbeef0000; i++; usleep(10 * 1000); - if (waitpid(child, &wstatus, WNOHANG)) + ret = waitpid(child, &wstatus, WNOHANG); + if (ret == child) break; + if (ret < 0) + ksft_exit_fail_perror("waitpid()"); } /* Finish whatever the paced sweep did not reach */ _ Patches currently in -mm which might be from kas@kernel.org are mm-huge_memory-do-not-touch-frozen-folios-in-deferred_split_isolate.patch mm-huge_memory-dequeue-the-deferred-split-after-the-split-freeze.patch selftests-mm-raise-the-khugepaged-test-case-cap.patch selftests-mm-skip-collapse_compound_extreme-where-the-pmd-is-too-large.patch selftests-mm-scale-khugepageds-collapse-wait-with-the-pmd-size.patch selftests-mm-skip-khugepaged-page-cache-cases-without-a-pmd-folio.patch selftests-mm-make-the-swap-cases-swapout-reliable.patch selftests-mm-stop-khugepaged-during-the-madv_collapse-cases.patch selftests-mm-move-is_backed_by_folio-into-vm_util.patch selftests-mm-add-folio-order-check-for-address-ranges.patch selftests-mm-add-folio-order-detection-self-check.patch selftests-mm-add-khugepaged-completion-barrier-helper.patch selftests-mm-add-order-parameterized-khugepaged-collapse-cases.patch selftests-mm-parameterize-the-mixed-source-collapse-case-by-source-order.patch selftests-mm-cover-a-shared-source-collapse-write-race.patch selftests-mm-cover-a-shared-source-collapse-write-race-fix.patch selftests-mm-run-every-supported-collapse-order-by-default.patch selftests-mm-check-that-one-khugepaged-pass-collapses-one-window.patch selftests-mm-add-khugepaged-race-harness.patch selftests-mm-add-khugepaged-race-harness-fix.patch selftests-mm-race-the-collapse-of-windows-with-holes.patch selftests-mm-add-memory-pressure-threads-to-the-khugepaged-race-harness.patch selftests-mm-zap-whole-pte-tables-in-the-khugepaged-race-harness.patch mm-huge_memory-add-folio_reset_partially_mapped.patch