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 29097402B99 for ; Sun, 20 Sep 2026 23:55:54 +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=1789948556; cv=none; b=jzFmGW045+1WDsKrPqCHDvbw6gXOYVSs3Ku3ZWdZF2NrYAQlUhfhVPMS4oecUI85T2NbL/IdW4fadvM0TxlWz7BjNljkjl+UhG35niNmUHoGaSzAr0RQeFk16gROYEMJlLw78oU1T1Lbtu8Rl/6ySyTEycXlldyyZaPX3nH/r0k= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1789948556; c=relaxed/simple; bh=Q6htbprbdyOW7CnXOHWfCJWKXGHbvpnn1jDBf/qNMjk=; h=Date:To:From:Subject:Message-Id; b=YpecvMN9CnfUsLavsyTIxPo+vEv5FrSFvI+ii88a4P3wqujoDlYT/k5d6U4pTFaQCaR0qAXBlP6686+Iasi8DDxNFaueQmgfDA1eOcsSKgIZqHGgRDPp9bkro+K79c/Jjn/VFLW/GtXD/0UBrrRpwX9MIEuqbCfXV9Psavr3xOU= 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=CzfGNR1m; 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="CzfGNR1m" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C51FF1F000FF; Sun, 20 Sep 2026 23:55:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1789948554; bh=ksTs/5ruy8vDAVMq9UjCSRwMG4APJN9CSZbBjCvq6bs=; h=Date:To:From:Subject; b=CzfGNR1mPxk/ysxi7OTQFgayFHtX5j98SEpeWczDYY/ZEPssLj7Ya0yMxMLOpyBqM xaxGHexXMbBmnu6/PMfzG5G2YMqlcY5maAFo5RUGppm5ouLhhzfXh/O+lDeo7BL+XY b59Gv+ngxY1hR1MqsGfXDHvJcgVl5JdfKw2t5ccQ= Date: Sun, 20 Sep 2026 16:55:54 -0700 To: mm-commits@vger.kernel.org,kas@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + selftests-mm-zap-whole-pte-tables-in-the-khugepaged-race-harness.patch added to mm-new branch Message-Id: <20260920235554.C51FF1F000FF@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: zap whole PTE tables in the khugepaged race harness has been added to the -mm mm-new branch. Its filename is selftests-mm-zap-whole-pte-tables-in-the-khugepaged-race-harness.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-zap-whole-pte-tables-in-the-khugepaged-race-harness.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: zap whole PTE tables in the khugepaged race harness Date: Sat, 19 Sep 2026 01:24:49 +0100 The harness's MADV_DONTNEED thread zaps 1 to 32 pages at a time, never a whole PMD-aligned area, and only a zap that covers a full table frees the table itself (CONFIG_PT_RECLAIM). Make the thread zap a whole PMD-aligned area about one iteration in 64, and keep the fine-grained zaps as the common case. The new case frees page tables, racing that against a collapse walking the same table. Assisted-by: LLM Link: https://lore.kernel.org/20260919002451.496763-20-kirill@shutemov.name Signed-off-by: Kiryl Shutsemau (Meta) Signed-off-by: Andrew Morton Tested-by: Muhammad Usama Anjum Cc: Alexander Gordeev Cc: Baolin Wang Cc: Barry Song Cc: "David Hildenbrand (arm)" Cc: Dev Jain Cc: Hugh Dickens Cc: Jason Gunthorpe Cc: kernel-team@meta.com Cc: Lance Yang Cc: Leon Romanovsky Cc: Liam Howlett Cc: Lorenzo Stoakes (ARM) Cc: Michal Hocko Cc: Mike Rapoport (Microsoft) Cc: Nico Pache (Red Hat) Cc: Ryan Roberts Cc: Shuah Khan (Samsung OSG) Cc: Suren Baghdasaryan Cc: Usama Arif Cc: "Vlastimil Babka (SUSE)" Cc: Zi Yan --- tools/testing/selftests/mm/khugepaged_race.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) --- a/tools/testing/selftests/mm/khugepaged_race.c~selftests-mm-zap-whole-pte-tables-in-the-khugepaged-race-harness +++ a/tools/testing/selftests/mm/khugepaged_race.c @@ -118,8 +118,21 @@ static void *dontneed_fn(void *arg) unsigned long page_idx = rand_page(&seed); unsigned long nr = 1UL << (rand_r(&seed) % 6); /* 1..32 pages */ - madvise(region + page_idx * page_size, - room_from(page_idx, nr) * page_size, MADV_DONTNEED); + /* + * Now and then zap a whole PMD-aligned area: only a zap that + * covers the full table frees the table itself (CONFIG_PT_RECLAIM). + */ + if (!(rand_r(&seed) % 64)) { + unsigned long area = page_idx / + (hpage_pmd_size / page_size); + + madvise(region + area * hpage_pmd_size, + hpage_pmd_size, MADV_DONTNEED); + } else { + madvise(region + page_idx * page_size, + room_from(page_idx, nr) * page_size, + MADV_DONTNEED); + } usleep(rand_r(&seed) % 500); } return NULL; _ 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 mm-huge_memory-add-folio_reset_partially_mapped.patch mm-khugepaged-drop-redundant-mm_struct-pin-in-madvise_collapse.patch mm-khugepaged-count-collapses-where-khugepaged-makes-them.patch mm-khugepaged-rename-mthp_present_ptes-bitmap-to-eligible_ptes.patch mm-collapse-add-collapseh-for-the-collapse-interface.patch mm-collapse-state-what-a-collapse-may-do-in-the-policy.patch mm-collapse-drop-the-collapse_possible-wrapper.patch mm-collapse-name-the-per-table-scan-reset-for-what-it-resets.patch mm-collapse-separate-scanning-a-pte-table-from-collapsing-it.patch mm-collapse-open-code-collapse_single_pmd-in-its-two-callers.patch mm-collapse-work-out-the-orders-a-vma-allows-once-per-vma.patch mm-collapse-declare-the-collapse-interface-in-collapseh.patch mm-collapse-implement-madv_collapse-in-madvisec.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-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-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