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 9146744C63 for ; Wed, 15 Oct 2025 00:03:16 +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=1760486596; cv=none; b=fyIpzp2bZTWa4G26gKm3+c7d0z1QVp3xyq2e0Gik0JfYoR+xVR1h1/bJ5vQqIGbin/9WYf+1iwSeH2I8TLkxg5i5a6am4WjHIf2w42BUyNlGUe/FMXq43RbMB5YptiPL6y/YxJ1nHqMVdcsBBMHDTC93r4B4AiH0qDn42XGrGkw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1760486596; c=relaxed/simple; bh=d8XNH/Dp0sznku8DRnkWPWl6LlYez06MFs2eP7vzgkk=; h=Date:To:From:Subject:Message-Id; b=RZGYTHt++Ap5Xlol8JHKzW6nb8KxYq0DDKbtLjDGpPTcgbQ7Hdm6UQw3CafoD3nF4o0m53Wjs68wWpzQxKQBgnjKJjdLez+70Aarkrn4ppoIfc42Jg9TNEgTw8zu6H1e9LoeMgkEoTUyq6qRd0meWujykE+zJR9Sdp3BaQNUW0Q= 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=neopJ72H; 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="neopJ72H" Received: by smtp.kernel.org (Postfix) with ESMTPSA id F100DC4CEE7; Wed, 15 Oct 2025 00:03:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1760486596; bh=d8XNH/Dp0sznku8DRnkWPWl6LlYez06MFs2eP7vzgkk=; h=Date:To:From:Subject:From; b=neopJ72HVPYYt/q++Y5OHDAMls+Megc5aTQ99ur6yy1vNVLj6iTM/BtHshBIvzl9a zz3/Le3X023NQ6MXKYDBPKq5ELkMnYnrOS53zwrpmDsOB8P7Bd+DaVtTZWQMEE4PoR bG3b1PMe8ctu9zrmGE25GNhCn3OKc2F/R4nY+ObE= Date: Tue, 14 Oct 2025 17:03:15 -0700 To: mm-commits@vger.kernel.org,ziy@nvidia.com,ryan.roberts@arm.com,npache@redhat.com,lorenzo.stoakes@oracle.com,liam.howlett@oracle.com,lance.yang@linux.dev,dev.jain@arm.com,david@redhat.com,baolin.wang@linux.alibaba.com,baohua@kernel.org,richard.weiyang@gmail.com,akpm@linux-foundation.org From: Andrew Morton Subject: + mm-huge_memory-optimize-old_order-derivation-during-folio-splitting.patch added to mm-new branch Message-Id: <20251015000315.F100DC4CEE7@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: mm/huge_memory: Optimize old_order derivation during folio splitting has been added to the -mm mm-new branch. Its filename is mm-huge_memory-optimize-old_order-derivation-during-folio-splitting.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/mm-huge_memory-optimize-old_order-derivation-during-folio-splitting.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: Wei Yang Subject: mm/huge_memory: Optimize old_order derivation during folio splitting Date: Tue, 14 Oct 2025 13:46:05 +0000 Folio splitting requires both the folio's original order (@old_order) and the new target order (@split_order). In the current implementation, @old_order is repeatedly retrieved using folio_order(). However, for every iteration after the first, the folio being split is the result of the previous split, meaning its order is already known to be equal to the previous iteration's @split_order. This commit optimizes the logic: * Instead of calling folio_order(), we now set @old_order directly to the value of @split_order from the previous iteration. * The initial @split_order (which was previously handled by a separate @start_order variable) is now directly used, and the redundant @start_order variable is removed. This change avoids unnecessary function calls and simplifies the loop setup. Link: https://lkml.kernel.org/r/20251014134606.22543-5-richard.weiyang@gmail.com Signed-off-by: Wei Yang Cc: Zi Yan Cc: Baolin Wang Cc: Barry Song Cc: David Hildenbrand Cc: Dev Jain Cc: Lance Yang Cc: Liam Howlett Cc: Lorenzo Stoakes Cc: Mariano Pache Cc: Ryan Roberts Signed-off-by: Andrew Morton --- mm/huge_memory.c | 7 +++---- 1 file changed, 3 insertions(+), 4 deletions(-) --- a/mm/huge_memory.c~mm-huge_memory-optimize-old_order-derivation-during-folio-splitting +++ a/mm/huge_memory.c @@ -3528,8 +3528,7 @@ static int __split_unmapped_folio(struct struct address_space *mapping, bool uniform_split) { bool is_anon = folio_test_anon(folio); - int order = folio_order(folio); - int start_order = uniform_split ? new_order : order - 1; + int old_order = folio_order(folio); int split_order; folio_clear_has_hwpoisoned(folio); @@ -3538,10 +3537,9 @@ static int __split_unmapped_folio(struct * split to new_order one order at a time. For uniform split, * folio is split to new_order directly. */ - for (split_order = start_order; + for (split_order = uniform_split ? new_order : old_order - 1; split_order >= new_order; split_order--) { - int old_order = folio_order(folio); int new_folios = 1UL << (old_order - split_order); /* order-1 anonymous folio is not supported */ @@ -3576,6 +3574,7 @@ static int __split_unmapped_folio(struct mod_mthp_stat(split_order, MTHP_STAT_NR_ANON, new_folios); } folio = page_folio(split_at); + old_order = split_order; } return 0; _ Patches currently in -mm which might be from richard.weiyang@gmail.com are mm-compaction-check-the-range-to-pageblock_pfn_to_page-is-within-the-zone-first.patch mm-compaction-fix-the-range-to-pageblock_pfn_to_page.patch mm-huge_memory-add-pmd-folio-to-ds_queue-in-do_huge_zero_wp_pmd.patch mm-khugepaged-unify-pmd-folio-installation-with-map_anon_folio_pmd.patch mm-huge_memory-only-get-folio_order-once-during-__folio_split.patch mm-huge_memory-cache-folio-attribute-in-__split_unmapped_folio.patch mm-huge_memory-update-folio-stat-after-successful-split.patch mm-huge_memory-optimize-and-simplify-folio-stat-update-after-split.patch mm-huge_memory-optimize-old_order-derivation-during-folio-splitting.patch mm-huge_memory-remove-redundant-split_order-=-new_order-check-in-uniform_split.patch