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 1C6931E7C1C for ; Sat, 2 Aug 2025 18:54:20 +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=1754160860; cv=none; b=hbECwQq+XTk1ktgZQji49BhuyT4WD9xPz6b8iqH8VkObGrcEXmioIvEhAAgaTwFP5LTqgRUMfw3FDq9+oBFsz3dg5ez1LYf5EyzkKHx5V0q0j+k85aF22S16VJxWFsdfH5W2atUT8lpbpFLKLKejBQgK3jvWl7p059bn+grIoA8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1754160860; c=relaxed/simple; bh=v8z8RpMwy62ExwrG76vRLLBSxRNXbw753tfpxqNqVwU=; h=Date:To:From:Subject:Message-Id; b=dpNiZCuRXMZUd8YISLW8TUtdAGDFFSam3FcE7XBy6q8Mp5XDOW+ibB00bWEY/A9mqLzU+sGVEs4s3Pm2/sBjBfpCmnlz5lEN2HGWcujov6e2Xul+Cd91wzprl2N2x7Fv93WAlxJpXkr0KBgsrNDUy/yuYqglrimlsBEZfk/lpXE= 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=fXdIqVQb; 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="fXdIqVQb" Received: by smtp.kernel.org (Postfix) with ESMTPSA id E735FC4CEEF; Sat, 2 Aug 2025 18:54:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1754160860; bh=v8z8RpMwy62ExwrG76vRLLBSxRNXbw753tfpxqNqVwU=; h=Date:To:From:Subject:From; b=fXdIqVQbr9nr1ONyz0IsuKxZuWgtwUUbJTGNUa650ziXz6iBV1W5m+UgeptRL5gbs HleNvqWvipJtF2o/9n4G5LHE+utOtgDVV6gjk78ps3hcpcjrQ33mYOYKoeGi7J1bM+ juUD0cTDcvGDkSuCBryjkY/xZwzdXJi85uvrp+v8= Date: Sat, 02 Aug 2025 11:54:19 -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: [merged mm-stable] khugepaged-optimize-collapse_pte_mapped_thp-by-pte-batching.patch removed from -mm tree Message-Id: <20250802185419.E735FC4CEEF@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: khugepaged: optimize collapse_pte_mapped_thp() by PTE batching has been removed from the -mm tree. Its filename was khugepaged-optimize-collapse_pte_mapped_thp-by-pte-batching.patch This patch was dropped because it was merged into the mm-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Dev Jain Subject: khugepaged: optimize collapse_pte_mapped_thp() by PTE batching Date: Thu, 24 Jul 2025 10:53:01 +0530 Use PTE batching to batch process PTEs mapping the same large folio. An improvement is expected due to batching mapcount manipulation on the folios, and for arm64 which supports contig mappings, the number of TLB flushes is also reduced. Note that we do not need to make a change to the check "if (folio_page(folio, i) != page)"; if i'th page of the folio is equal to the first page of our batch, then i + 1, .... i + nr_batch_ptes - 1 pages of the folio will be equal to the corresponding pages of our batch mapping consecutive pages. Link: https://lkml.kernel.org/r/20250724052301.23844-4-dev.jain@arm.com Signed-off-by: Dev Jain Acked-by: David Hildenbrand Reviewed-by: Baolin Wang Reviewed-by: Lorenzo Stoakes Reviewed-by: Zi Yan Cc: Barry Song Cc: Liam Howlett Cc: Mariano Pache Cc: Ryan Roberts Signed-off-by: Andrew Morton --- mm/khugepaged.c | 33 +++++++++++++++++++++------------ 1 file changed, 21 insertions(+), 12 deletions(-) --- a/mm/khugepaged.c~khugepaged-optimize-collapse_pte_mapped_thp-by-pte-batching +++ a/mm/khugepaged.c @@ -1503,15 +1503,17 @@ static int set_huge_pmd(struct vm_area_s int collapse_pte_mapped_thp(struct mm_struct *mm, unsigned long addr, bool install_pmd) { + int nr_mapped_ptes = 0, result = SCAN_FAIL; + unsigned int nr_batch_ptes; struct mmu_notifier_range range; bool notified = false; unsigned long haddr = addr & HPAGE_PMD_MASK; + unsigned long end = haddr + HPAGE_PMD_SIZE; struct vm_area_struct *vma = vma_lookup(mm, haddr); struct folio *folio; pte_t *start_pte, *pte; pmd_t *pmd, pgt_pmd; spinlock_t *pml = NULL, *ptl; - int nr_ptes = 0, result = SCAN_FAIL; int i; mmap_assert_locked(mm); @@ -1625,11 +1627,15 @@ int collapse_pte_mapped_thp(struct mm_st goto abort; /* step 2: clear page table and adjust rmap */ - for (i = 0, addr = haddr, pte = start_pte; - i < HPAGE_PMD_NR; i++, addr += PAGE_SIZE, pte++) { + for (i = 0, addr = haddr, pte = start_pte; i < HPAGE_PMD_NR; + i += nr_batch_ptes, addr += nr_batch_ptes * PAGE_SIZE, + pte += nr_batch_ptes) { + unsigned int max_nr_batch_ptes = (end - addr) >> PAGE_SHIFT; struct page *page; pte_t ptent = ptep_get(pte); + nr_batch_ptes = 1; + if (pte_none(ptent)) continue; /* @@ -1643,26 +1649,29 @@ int collapse_pte_mapped_thp(struct mm_st goto abort; } page = vm_normal_page(vma, addr, ptent); + if (folio_page(folio, i) != page) goto abort; + nr_batch_ptes = folio_pte_batch(folio, pte, ptent, max_nr_batch_ptes); + /* * Must clear entry, or a racing truncate may re-remove it. * TLB flush can be left until pmdp_collapse_flush() does it. * PTE dirty? Shmem page is already dirty; file is read-only. */ - ptep_clear(mm, addr, pte); - folio_remove_rmap_pte(folio, page, vma); - nr_ptes++; + clear_ptes(mm, addr, pte, nr_batch_ptes); + folio_remove_rmap_ptes(folio, page, nr_batch_ptes, vma); + nr_mapped_ptes += nr_batch_ptes; } if (!pml) spin_unlock(ptl); /* step 3: set proper refcount and mm_counters. */ - if (nr_ptes) { - folio_ref_sub(folio, nr_ptes); - add_mm_counter(mm, mm_counter_file(folio), -nr_ptes); + if (nr_mapped_ptes) { + folio_ref_sub(folio, nr_mapped_ptes); + add_mm_counter(mm, mm_counter_file(folio), -nr_mapped_ptes); } /* step 4: remove empty page table */ @@ -1695,10 +1704,10 @@ maybe_install_pmd: : SCAN_SUCCEED; goto drop_folio; abort: - if (nr_ptes) { + if (nr_mapped_ptes) { flush_tlb_mm(mm); - folio_ref_sub(folio, nr_ptes); - add_mm_counter(mm, mm_counter_file(folio), -nr_ptes); + folio_ref_sub(folio, nr_mapped_ptes); + add_mm_counter(mm, mm_counter_file(folio), -nr_mapped_ptes); } unlock: if (start_pte) _ Patches currently in -mm which might be from dev.jain@arm.com are