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 3BECEBE65 for ; Fri, 4 Jul 2025 00:59:07 +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=1751590748; cv=none; b=FQ0OFy8LZvfuVLKPsjmYSs6pgfged2RPwHTur896Oplzr6o62ZMueAzO6QMxTsfqVKFkyBO12vFRexj1P/v3DPNBZwo7MD3er7hbhQVU/buvTzrME7IMRyIYi6FU0KE0JhKZR4liQbKo6XhbJxuJlLqKWfvor7I5rb2xwbWE0HU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1751590748; c=relaxed/simple; bh=8/RcywKK/aa6b1uruZcWGQdyPkb9dFxCS+GoDrvMe/Y=; h=Date:To:From:Subject:Message-Id; b=aVQQRThPUjHfIfnX5rnYhClxn4R38lNo4NtToEg1CBocVdfDmJeuWA4CYb5CEbJLeyoJPJDH9I5PGaQ/Vaw9AhRNHeEcTdoyNSgKZKuoAeRFjzVi152cjI17jMJ9fedeEt7ZnVDqo4h7yr2uOUFN67WGXaZ4oqHWBei5SdXDOUE= 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=rWyzVDvu; 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="rWyzVDvu" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 93D8AC4CEE3; Fri, 4 Jul 2025 00:59:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1751590747; bh=8/RcywKK/aa6b1uruZcWGQdyPkb9dFxCS+GoDrvMe/Y=; h=Date:To:From:Subject:From; b=rWyzVDvutc1ZoI3r8qCzWltsk8ORjPg+nkDpMITSyGRIYk8fgSnpmOCVfhLypDpfI XgmG/k/Z63FXW1u1aLsZruG0osZoUa1siTrDU1uZgrNM+dy6C1OYarFRiDGYxmfefe sM4dUZZcUZxTXrLxsKAhcVbt7f3ZQs6dmDvhjF+8= Date: Thu, 03 Jul 2025 17:59:07 -0700 To: mm-commits@vger.kernel.org,zokeefe@google.com,ziy@nvidia.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,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: + introduce-khugepaged_collapse_single_pmd-to-unify-khugepaged-and-madvise_collapse.patch added to mm-new branch Message-Id: <20250704005907.93D8AC4CEE3@smtp.kernel.org> Precedence: bulk X-Mailing-List: mm-commits@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The patch titled Subject: introduce khugepaged_collapse_single_pmd to unify khugepaged and madvise_collapse has been added to the -mm mm-new branch. Its filename is introduce-khugepaged_collapse_single_pmd-to-unify-khugepaged-and-madvise_collapse.patch This patch will shortly appear at https://git.kernel.org/pub/scm/linux/kernel/git/akpm/25-new.git/tree/patches/introduce-khugepaged_collapse_single_pmd-to-unify-khugepaged-and-madvise_collapse.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: introduce khugepaged_collapse_single_pmd to unify khugepaged and madvise_collapse Date: Tue, 1 Jul 2025 23:57:29 -0600 The khugepaged daemon and madvise_collapse have two different implementations that do almost the same thing. Create khugepaged_collapse_single_pmd to increase code reuse and create an entry point these two users. Refactor madvise_collapse and khugepaged_scan_mm_slot to use the new khugepaged_collapse_single_pmd function. This introduces a minor behavioral change that is most likely an undiscovered bug. The current implementation of khugepaged tests khugepaged_test_exit_or_disable before calling khugepaged_pte_mapped_thp, but we weren't doing it in the madvise_collapse case. By unifying these two callers madvise_collapse now also performs this check. Link: https://lkml.kernel.org/r/20250702055742.102808-3-npache@redhat.com Signed-off-by: Nico Pache Reviewed-by: Baolin Wang Cc: Andrea Arcangeli Cc: Anshuman Khandual Cc: Bagas Sanjaya Cc: Barry Song Cc: Catalin Marinas Cc: Christoph Lameter (Ampere) Cc: David Hildenbrand Cc: David Rientjes Cc: Dev Jain 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: Steven Rostedt Cc: Suren Baghdasaryan Cc: Thomas Hellstrom Cc: Usama Arif Cc: Vishal Moola (Oracle) Cc: Will Deacon Cc: Zach O'Keefe Cc: Zi Yan Signed-off-by: Andrew Morton --- mm/khugepaged.c | 95 +++++++++++++++++++++++----------------------- 1 file changed, 49 insertions(+), 46 deletions(-) --- a/mm/khugepaged.c~introduce-khugepaged_collapse_single_pmd-to-unify-khugepaged-and-madvise_collapse +++ a/mm/khugepaged.c @@ -2354,6 +2354,50 @@ static int khugepaged_scan_file(struct m return result; } +/* + * Try to collapse a single PMD starting at a PMD aligned addr, and return + * the results. + */ +static int khugepaged_collapse_single_pmd(unsigned long addr, + struct vm_area_struct *vma, bool *mmap_locked, + struct collapse_control *cc) +{ + int result = SCAN_FAIL; + struct mm_struct *mm = vma->vm_mm; + + if (IS_ENABLED(CONFIG_SHMEM) && !vma_is_anonymous(vma)) { + struct file *file = get_file(vma->vm_file); + pgoff_t pgoff = linear_page_index(vma, addr); + + mmap_read_unlock(mm); + *mmap_locked = false; + result = khugepaged_scan_file(mm, addr, file, pgoff, cc); + fput(file); + if (result == SCAN_PTE_MAPPED_HUGEPAGE) { + mmap_read_lock(mm); + *mmap_locked = true; + if (khugepaged_test_exit_or_disable(mm)) { + mmap_read_unlock(mm); + *mmap_locked = false; + result = SCAN_ANY_PROCESS; + goto end; + } + result = collapse_pte_mapped_thp(mm, addr, + !cc->is_khugepaged); + if (result == SCAN_PMD_MAPPED) + result = SCAN_SUCCEED; + mmap_read_unlock(mm); + *mmap_locked = false; + } + } else { + result = khugepaged_scan_pmd(mm, vma, addr, mmap_locked, cc); + } + if (cc->is_khugepaged && result == SCAN_SUCCEED) + ++khugepaged_pages_collapsed; +end: + return result; +} + static unsigned int khugepaged_scan_mm_slot(unsigned int pages, int *result, struct collapse_control *cc) __releases(&khugepaged_mm_lock) @@ -2428,34 +2472,9 @@ skip: VM_BUG_ON(khugepaged_scan.address < hstart || khugepaged_scan.address + HPAGE_PMD_SIZE > hend); - if (!vma_is_anonymous(vma)) { - struct file *file = get_file(vma->vm_file); - pgoff_t pgoff = linear_page_index(vma, - khugepaged_scan.address); - - mmap_read_unlock(mm); - mmap_locked = false; - *result = hpage_collapse_scan_file(mm, - khugepaged_scan.address, file, pgoff, cc); - fput(file); - if (*result == SCAN_PTE_MAPPED_HUGEPAGE) { - mmap_read_lock(mm); - if (hpage_collapse_test_exit_or_disable(mm)) - goto breakouterloop; - *result = collapse_pte_mapped_thp(mm, - khugepaged_scan.address, false); - if (*result == SCAN_PMD_MAPPED) - *result = SCAN_SUCCEED; - mmap_read_unlock(mm); - } - } else { - *result = hpage_collapse_scan_pmd(mm, vma, - khugepaged_scan.address, &mmap_locked, cc); - } - - if (*result == SCAN_SUCCEED) - ++khugepaged_pages_collapsed; + *result = khugepaged_collapse_single_pmd(khugepaged_scan.address, + vma, &mmap_locked, cc); /* move to next address */ khugepaged_scan.address += HPAGE_PMD_SIZE; progress += HPAGE_PMD_NR; @@ -2772,35 +2791,19 @@ int madvise_collapse(struct vm_area_stru mmap_assert_locked(mm); memset(cc->node_load, 0, sizeof(cc->node_load)); nodes_clear(cc->alloc_nmask); - if (!vma_is_anonymous(vma)) { - struct file *file = get_file(vma->vm_file); - pgoff_t pgoff = linear_page_index(vma, addr); - mmap_read_unlock(mm); - mmap_locked = false; - result = hpage_collapse_scan_file(mm, addr, file, pgoff, - cc); - fput(file); - } else { - result = hpage_collapse_scan_pmd(mm, vma, addr, - &mmap_locked, cc); - } + result = khugepaged_collapse_single_pmd(addr, vma, &mmap_locked, cc); + if (!mmap_locked) *lock_dropped = true; -handle_result: switch (result) { case SCAN_SUCCEED: case SCAN_PMD_MAPPED: ++thps; break; - case SCAN_PTE_MAPPED_HUGEPAGE: - BUG_ON(mmap_locked); - mmap_read_lock(mm); - result = collapse_pte_mapped_thp(mm, addr, true); - mmap_read_unlock(mm); - goto handle_result; /* Whitelisted set of results where continuing OK */ + case SCAN_PTE_MAPPED_HUGEPAGE: case SCAN_PMD_NULL: case SCAN_PTE_NON_PRESENT: case SCAN_PTE_UFFD_WP: _ 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-allow-madvise_collapse-to-check-all-anonymous-mthp-orders.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