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 C505286328 for ; Thu, 24 Jul 2025 22:15:18 +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=1753395318; cv=none; b=T0Ju0WIRWzBlvAVTw7HEF30j/sptMfQ91Ww23oon80patEn3wT/oiAoRmYLmCpL1OUMFpA+nLXS1Kjn8SC2FeWzc4fqc9DaeAlDg4sSKEHOrOqqE3ZVHV8stg0njzN6vRKErT0UXqjnfizZZveuwbCvZovV4/tnXhDhp4REL8Bc= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753395318; c=relaxed/simple; bh=dg+3+u2QEL6J7E5/Qkq943n27/hT7ufqJPh+eQNYdcY=; h=Date:To:From:Subject:Message-Id; b=VrPCtZCacPcRE7BSgqeZ/qnaUXbtf5MrB/50FcUMFskYFoTlh2GluYb3CAdfrYi28uzC23zFSrcQL4MMayzq26ntzYvl4LE8nUN08J2yZ2NsRI9YI1jzzFnCdJ25Fg91Ly45M19LYCw4ALTlKdunJ6ZEdui/vHIkQal8Ezw1abw= 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=FURRBBAz; 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="FURRBBAz" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 52FC2C4CEED; Thu, 24 Jul 2025 22:15:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1753395318; bh=dg+3+u2QEL6J7E5/Qkq943n27/hT7ufqJPh+eQNYdcY=; h=Date:To:From:Subject:From; b=FURRBBAz8lfjcySj9/kcBcx+YmkJqxI8qGEZ1gs0Ga1MBIciBtyDGeAyatqqZUKSM 4FazvZQW005pIcvYXOOPCTkqlOt+HEM7KNhzTzwV7oIERGM+k6QMEPgZERlQpY8us4 BfTE9mWQk1Jv7k7E/3gxnOlpfxc30QVygKslxOBs= Date: Thu, 24 Jul 2025 15:15:17 -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,david@redhat.com,baolin.wang@linux.alibaba.com,baohua@kernel.org,dev.jain@arm.com,akpm@linux-foundation.org From: Andrew Morton Subject: + khugepaged-optimize-__collapse_huge_page_copy_succeeded-by-pte-batching.patch added to mm-new branch Message-Id: <20250724221518.52FC2C4CEED@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: khugepaged: optimize __collapse_huge_page_copy_succeeded() by PTE batching has been added to the -mm mm-new branch. Its filename is khugepaged-optimize-__collapse_huge_page_copy_succeeded-by-pte-batching.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/khugepaged-optimize-__collapse_huge_page_copy_succeeded-by-pte-batching.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: Dev Jain Subject: khugepaged: optimize __collapse_huge_page_copy_succeeded() by PTE batching Date: Thu, 24 Jul 2025 10:53:00 +0530 Use PTE batching to batch process PTEs mapping the same large folio. An improvement is expected due to batching refcount-mapcount manipulation on the folios, and for arm64 which supports contig mappings, the number of TLB flushes is also reduced. Link: https://lkml.kernel.org/r/20250724052301.23844-3-dev.jain@arm.com Signed-off-by: Dev Jain Acked-by: David Hildenbrand Reviewed-by: Baolin Wang Reviewed-by: Lorenzo Stoakes Cc: Barry Song Cc: Liam Howlett Cc: Mariano Pache Cc: Ryan Roberts Cc: Zi Yan Signed-off-by: Andrew Morton --- mm/khugepaged.c | 25 ++++++++++++++++++------- 1 file changed, 18 insertions(+), 7 deletions(-) --- a/mm/khugepaged.c~khugepaged-optimize-__collapse_huge_page_copy_succeeded-by-pte-batching +++ a/mm/khugepaged.c @@ -700,12 +700,15 @@ static void __collapse_huge_page_copy_su spinlock_t *ptl, struct list_head *compound_pagelist) { + unsigned long end = address + HPAGE_PMD_SIZE; struct folio *src, *tmp; - pte_t *_pte; pte_t pteval; + pte_t *_pte; + unsigned int nr_ptes; - for (_pte = pte; _pte < pte + HPAGE_PMD_NR; - _pte++, address += PAGE_SIZE) { + for (_pte = pte; _pte < pte + HPAGE_PMD_NR; _pte += nr_ptes, + address += nr_ptes * PAGE_SIZE) { + nr_ptes = 1; pteval = ptep_get(_pte); if (pte_none(pteval) || is_zero_pfn(pte_pfn(pteval))) { add_mm_counter(vma->vm_mm, MM_ANONPAGES, 1); @@ -722,18 +725,26 @@ static void __collapse_huge_page_copy_su struct page *src_page = pte_page(pteval); src = page_folio(src_page); - if (!folio_test_large(src)) + + if (folio_test_large(src)) { + unsigned int max_nr_ptes = (end - address) >> PAGE_SHIFT; + + nr_ptes = folio_pte_batch(src, _pte, pteval, max_nr_ptes); + } else { release_pte_folio(src); + } + /* * ptl mostly unnecessary, but preempt has to * be disabled to update the per-cpu stats * inside folio_remove_rmap_pte(). */ spin_lock(ptl); - ptep_clear(vma->vm_mm, address, _pte); - folio_remove_rmap_pte(src, src_page, vma); + clear_ptes(vma->vm_mm, address, _pte, nr_ptes); + folio_remove_rmap_ptes(src, src_page, nr_ptes, vma); spin_unlock(ptl); - free_folio_and_swap_cache(src); + free_swap_cache(src); + folio_put_refs(src, nr_ptes); } } _ Patches currently in -mm which might be from dev.jain@arm.com are mm-refactor-mm_cp_prot_numa-skipping-case-into-new-function.patch mm-optimize-mprotect-for-mm_cp_prot_numa-by-batch-skipping-ptes.patch mm-add-batched-versions-of-ptep_modify_prot_start-commit.patch mm-introduce-fpb_respect_write-for-pte-batching-infrastructure.patch mm-split-can_change_pte_writable-into-private-and-shared-parts.patch mm-optimize-mprotect-by-pte-batching.patch arm64-add-batched-versions-of-ptep_modify_prot_start-commit.patch khugepaged-optimize-__collapse_huge_page_copy_succeeded-by-pte-batching.patch khugepaged-optimize-collapse_pte_mapped_thp-by-pte-batching.patch