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 E9F1E4A6CCB for ; Tue, 8 Sep 2026 19:50:02 +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=1788897004; cv=none; b=P369iXJevhizWFxzb7PQCUzSb/vvov7ExzDApgSckn+aZDFhjdFJ5lw8Z3jTbPXJiH/iipkaSIBeX/9V6o0cvvWkPs71Z6uJVfT+ceJvSB+Sqk6jYk3LS1JCqXanTjmqArnSfjt3ZjYOTb/Be4rGmDpH/oPiNUq+yLfL3atOScg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1788897004; c=relaxed/simple; bh=hrjW6+WZxzTWgj0iWtRFe6q0TQE91IsF7quouksDW30=; h=Date:To:From:Subject:Message-Id; b=i9CcEKmP6QfVEA4eX2F03xOe9oKVlYmN0oNHwB42BBWDfbf/g9xP3EeKRazgKXms8tgwf71kj/hWBJOx7b5KxpDt1zWn6CPM0yCnTITF/V8NsbL07LdaiQTlxp3QENZLmhe1XXvKatKzyFUhpQfBTcAFqvQEP0fltiHXHfbKrVs= 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=KG0YNtQS; 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="KG0YNtQS" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 4C9F61F00A3A; Tue, 8 Sep 2026 19:50:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux-foundation.org; s=korg; t=1788897002; bh=IyC23B6pG1xrK1ZUDfbx1hUWRoFcFANWubLNYNDjee4=; h=Date:To:From:Subject; b=KG0YNtQSDQnxRBQB+A00Uhs9C4OP/kdjRVCl5MsLHdevr7MDimI0h9nJmJYO+WMX+ 70PzM4u2Dv2ixb8BZ9o31dmbugPdpFSlwIQwnn1g1rE3QHsyFv6FxpIJ5MWdH/msxi DebrAhNPasl5sRyJRd+9l8il+4cTjCYUxln8cO+Y= Date: Tue, 08 Sep 2026 12:50:01 -0700 To: mm-commits@vger.kernel.org,kas@kernel.org,akpm@linux-foundation.org From: Andrew Morton Subject: + selftests-mm-raise-the-khugepaged-test-case-cap.patch added to mm-new branch Message-Id: <20260908195002.4C9F61F00A3A@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: raise the khugepaged test-case cap has been added to the -mm mm-new branch. Its filename is selftests-mm-raise-the-khugepaged-test-case-cap.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/selftests-mm-raise-the-khugepaged-test-case-cap.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: raise the khugepaged test-case cap Date: Tue, 8 Sep 2026 13:50:47 +0100 Patch series "selftests/mm: improve khugepaged coverage", v5. khugepaged collapses to mTHP orders since 7.2, and 7.3 added three selftest cases for it: the generic collapse cases run at one order named by -c, with the result detected by counting folios of that order. That leaves the collapse path largely untested. The suite does not run where a PMD is 512M. A folio count cannot say where a collapse landed. Fixed sleeps cannot tell "not collapsed" from "not scanned yet". And nothing exercises collapse under contention. Close those gaps in order: - Make the suite run at a 512M PMD: scale the collapse wait with the PMD size, skip what such a PMD cannot serve, make the swapout the swap cases depend on deterministic, and keep khugepaged out of the MADV_COLLAPSE cases. - Detect results per window rather than by count, with folio-order helpers in vm_util that are checked against the kernel before any collapse test trusts them. - Drive khugepaged deterministically: a completion barrier that wakes the daemon and waits for a full pass, and a check that one pass yields one attributed collapse. - Cover collapse at every supported order by default: which window collapses, occupancy at both limits, sources that are already large folios, and a fork-shared source under concurrent writes. - Race collapse against everything that can touch its sources, at both occupancy limits and over whole-table zaps, checked by content and by the kernel's own assertions. Everything passes on an unmodified kernel. This patch (of 19): TEST() ends the run with "MAX_TEST_CASES is too small" when the table fills, and the table holds 64. A full invocation already registers 63, so the next case added anywhere aborts the whole suite before a single test runs. Raise the cap to 256. The table is a static array of small structs, so the room costs nothing worth counting. Assisted-by: LLM Link: https://lore.kernel.org/20260908125105.1510704-1-kirill@shutemov.name Link: https://lore.kernel.org/20260908125105.1510704-2-kirill@shutemov.name Signed-off-by: Kiryl Shutsemau (Meta) Acked-by: Usama Arif Acked-by: Lorenzo Stoakes (ARM) Reviewed-by: Mike Rapoport (Microsoft) Cc: Alexander Gordeev Cc: Baolin Wang Cc: Barry Song Cc: David Hildenbrand Cc: Dev Jain Cc: Hugh Dickins Cc: Jason Gunthorpe Cc: Lance Yang Cc: Leon Romanovsky Cc: Liam R. Howlett Cc: Michal Hocko Cc: Ryan Roberts Cc: Shuah Khan Cc: Suren Baghdasaryan Cc: Vlastimil Babka Cc: Zi Yan Cc: Muhammad Usama Anjum Signed-off-by: Andrew Morton --- tools/testing/selftests/mm/khugepaged.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/tools/testing/selftests/mm/khugepaged.c~selftests-mm-raise-the-khugepaged-test-case-cap +++ a/tools/testing/selftests/mm/khugepaged.c @@ -1290,7 +1290,7 @@ struct test_case { test_fn fn; }; -#define MAX_TEST_CASES 64 +#define MAX_TEST_CASES 256 static struct test_case test_cases[MAX_TEST_CASES]; static int nr_test_cases; _ 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-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