From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 3F978155725 for ; Mon, 28 Apr 2025 19:01:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745866895; cv=none; b=CMIufm7cZe9gsbcOfFNV62tVVO+3DqO9KEC6YCU7vIgCkxKDfUedFtAflkxkRyuE3WJmqxsvWPVt+idItaU0OoApt/TUAWiakRg3BcafX3vwsTrWmtmHSNridQP2X8u0ekJZBwMCL8+otaR+yTypFrxIxkizfvbzIJLpCALDR10= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1745866895; c=relaxed/simple; bh=3czsNLGgpGZRNTT0BsAY7WraIk6J51HCi0/Ec0EptM8=; h=Date:To:From:Subject:Message-Id; b=d9XNlMh5YfvkQ6bchpNGVOEc8Z775eG/1gCz3LDdPxsg5eAZT7vRylXvwt5TnOU5lMCQMaXx5QUap8U47uZ+EwFUgOWdVgLHAJKRovAbm4oBt5LBGSxs/P5FrxV2YgoGUjMVkyHULDXHOhX41y2qCjSgDdqFiFB8gJgcOBsxT+o= 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=SJMFPTbt; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="SJMFPTbt" Received: by smtp.kernel.org (Postfix) with ESMTPSA id EA928C4CEE4; Mon, 28 Apr 2025 19:01:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1745866895; bh=3czsNLGgpGZRNTT0BsAY7WraIk6J51HCi0/Ec0EptM8=; h=Date:To:From:Subject:From; b=SJMFPTbtriV5RjLr5Lr2FSPZpes/+yRri7t+SlWM4uMhdU/eH1Xo4u3jdXpfGfipR NvMsLnMDWJonWDx9AJOdLc6OL97VTSqO52sxS/teAsIi2qkYQ9vJWRkbhk++xroRYG yHYT66hLr8Ia/w5i+dbSoH5ddwL0PCt0frvyxGjE= Date: Mon, 28 Apr 2025 12:01:34 -0700 To: mm-commits@vger.kernel.org,zokeefe@google.com,ziy@nvidia.com,yang@os.amperecomputing.com,willy@infradead.org,will@kernel.org,wangkefeng.wang@huawei.com,vishal.moola@gmail.com,usamaarif642@gmail.com,tiwai@suse.de,thomas.hellstrom@linux.intel.com,surenb@google.com,sunnanyong@huawei.com,shuah@kernel.org,ryan.roberts@arm.com,rostedt@goodmis.org,rientjes@google.com,rdunlap@infradead.org,raquini@redhat.com,peterx@redhat.com,mhocko@suse.com,mhiramat@kernel.org,mathieu.desnoyers@efficios.com,lorenzo.stoakes@oracle.com,liam.howlett@oracle.com,kirill.shutemov@linux.intel.com,jack@suse.cz,hannes@cmpxchg.org,dev.jain@arm.com,david@redhat.com,corbet@lwn.net,cl@gentwo.org,catalin.marinas@arm.com,baolin.wang@linux.alibaba.com,baohua@kernel.org,bagasdotme@gmail.com,anshuman.khandual@arm.com,aarcange@redhat.com,npache@redhat.com,akpm@linux-foundation.org From: Andrew Morton Subject: + khugepaged-skip-collapsing-mthp-to-smaller-orders.patch added to mm-new branch Message-Id: <20250428190134.EA928C4CEE4@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: khugepaged: skip collapsing mTHP to smaller orders has been added to the -mm mm-new branch. Its filename is khugepaged-skip-collapsing-mthp-to-smaller-orders.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/khugepaged-skip-collapsing-mthp-to-smaller-orders.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. 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 the mm-everything branch at git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm and is updated there every 2-3 working days ------------------------------------------------------ From: Nico Pache Subject: khugepaged: skip collapsing mTHP to smaller orders Date: Mon, 28 Apr 2025 12:12:14 -0600 khugepaged may try to collapse a mTHP to a smaller mTHP, resulting in some pages being unmapped. Skip these cases until we have a way to check if its ok to collapse to a smaller mTHP size (like in the case of a partially mapped folio). This patch is inspired by Dev Jain's work on khugepaged mTHP support [1]. Link: https://lore.kernel.org/lkml/20241216165105.56185-11-dev.jain@arm.com/ [1] Link: https://lkml.kernel.org/r/20250428181218.85925-9-npache@redhat.com Co-developed-by: Dev Jain Signed-off-by: Dev Jain Signed-off-by: Nico Pache Cc: Andrea Arcangeli Cc: Anshuman Khandual Cc: Bagas Sanjaya Cc: Baolin Wang Cc: Barry Song Cc: Catalin Marinas Cc: Christoph Lameter (Ampere) Cc: David Hildenbrand Cc: David Rientjes Cc: Jan Kara Cc: Johannes Weiner Cc: Jonathan Corbet Cc: Kefeng Wang Cc: Kirill A. Shuemov Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: "Masami Hiramatsu (Google)" Cc: Mathieu Desnoyers Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Nanyong Sun Cc: Peter Xu Cc: Rafael Aquini Cc: Randy Dunlap Cc: Reported-by:Takashi Iwai Cc: Ryan Roberts Cc: Shuah Khan Cc: Steven Rostedt Cc: Suren Baghdasaryan Cc: Thomas Hellstrom Cc: Usama Arif Cc: Vishal Moola (Oracle) Cc: Will Deacon Cc: Yang Shi Cc: Zach O'Keefe Cc: Zi Yan Signed-off-by: Andrew Morton --- mm/khugepaged.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) --- a/mm/khugepaged.c~khugepaged-skip-collapsing-mthp-to-smaller-orders +++ a/mm/khugepaged.c @@ -625,7 +625,12 @@ static int __collapse_huge_page_isolate( folio = page_folio(page); VM_BUG_ON_FOLIO(!folio_test_anon(folio), folio); - /* See hpage_collapse_scan_pmd(). */ + if (order != HPAGE_PMD_ORDER && folio_order(folio) >= order) { + result = SCAN_PTE_MAPPED_HUGEPAGE; + goto out; + } + + /* See khugepaged_scan_pmd(). */ if (folio_maybe_mapped_shared(folio)) { ++shared; if (order != HPAGE_PMD_ORDER || (cc->is_khugepaged && _ Patches currently in -mm which might be from npache@redhat.com are khugepaged-rename-hpage_collapse_-to-khugepaged_.patch introduce-khugepaged_collapse_single_pmd-to-unify-khugepaged-and-madvise_collapse.patch khugepaged-generalize-hugepage_vma_revalidate-for-mthp-support.patch khugepaged-generalize-__collapse_huge_page_-for-mthp-support.patch khugepaged-introduce-khugepaged_scan_bitmap-for-mthp-support.patch khugepaged-add-mthp-support.patch khugepaged-skip-collapsing-mthp-to-smaller-orders.patch khugepaged-avoid-unnecessary-mthp-collapse-attempts.patch khugepaged-improve-tracepoints-for-mthp-orders.patch khugepaged-add-per-order-mthp-khugepaged-stats.patch documentation-mm-update-the-admin-guide-for-mthp-collapse.patch mm-defer-thp-insertion-to-khugepaged.patch mm-document-mthp-defer-usage.patch khugepaged-add-defer-option-to-mthp-options.patch selftests-mm-add-defer-to-thp-setting-parser.patch