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 16ED512B93; Fri, 29 Dec 2023 19:07:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux-foundation.org header.i=@linux-foundation.org header.b="d3ZFvyjK" Received: by smtp.kernel.org (Postfix) with ESMTPSA id C4EF3C433C8; Fri, 29 Dec 2023 19:07:29 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linux-foundation.org; s=korg; t=1703876849; bh=wB9g3K5uRJDJKPewUbc3L9soV5ziv4h2s0ZAqdBR+ek=; h=Date:To:From:Subject:From; b=d3ZFvyjKpYN0iXsFYFZAio2x8DgAOELIz/QoF3N7Y9vx5Ez26SRJDMuucF6wBeHFD TbDlZWfB5xFBigqxUCPiiYBppTM37GB9ZPPlLbuKWHQpBlF9A2MXd7/16HkzTzM1ou PPltI4QgoLod7OOJebpOFua34WI7tIv0CviJGmeM= Date: Fri, 29 Dec 2023 11:07:29 -0800 To: mm-commits@vger.kernel.org,stable@vger.kernel.org,yuzhao@google.com,akpm@linux-foundation.org From: Andrew Morton Subject: [merged mm-hotfixes-stable] mm-mglru-skip-special-vmas-in-lru_gen_look_around.patch removed from -mm tree Message-Id: <20231229190729.C4EF3C433C8@smtp.kernel.org> Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: The quilt patch titled Subject: mm/mglru: skip special VMAs in lru_gen_look_around() has been removed from the -mm tree. Its filename was mm-mglru-skip-special-vmas-in-lru_gen_look_around.patch This patch was dropped because it was merged into the mm-hotfixes-stable branch of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm ------------------------------------------------------ From: Yu Zhao Subject: mm/mglru: skip special VMAs in lru_gen_look_around() Date: Fri, 22 Dec 2023 21:56:47 -0700 Special VMAs like VM_PFNMAP can contain anon pages from COW. There isn't much profit in doing lookaround on them. Besides, they can trigger the pte_special() warning in get_pte_pfn(). Skip them in lru_gen_look_around(). Link: https://lkml.kernel.org/r/20231223045647.1566043-1-yuzhao@google.com Fixes: 018ee47f1489 ("mm: multi-gen LRU: exploit locality in rmap") Signed-off-by: Yu Zhao Reported-by: syzbot+03fd9b3f71641f0ebf2d@syzkaller.appspotmail.com Closes: https://lore.kernel.org/000000000000f9ff00060d14c256@google.com/ Cc: Signed-off-by: Andrew Morton --- mm/vmscan.c | 13 +++++++++---- 1 file changed, 9 insertions(+), 4 deletions(-) --- a/mm/vmscan.c~mm-mglru-skip-special-vmas-in-lru_gen_look_around +++ a/mm/vmscan.c @@ -3955,6 +3955,7 @@ void lru_gen_look_around(struct page_vma int young = 0; pte_t *pte = pvmw->pte; unsigned long addr = pvmw->address; + struct vm_area_struct *vma = pvmw->vma; struct folio *folio = pfn_folio(pvmw->pfn); bool can_swap = !folio_is_file_lru(folio); struct mem_cgroup *memcg = folio_memcg(folio); @@ -3969,11 +3970,15 @@ void lru_gen_look_around(struct page_vma if (spin_is_contended(pvmw->ptl)) return; + /* exclude special VMAs containing anon pages from COW */ + if (vma->vm_flags & VM_SPECIAL) + return; + /* avoid taking the LRU lock under the PTL when possible */ walk = current->reclaim_state ? current->reclaim_state->mm_walk : NULL; - start = max(addr & PMD_MASK, pvmw->vma->vm_start); - end = min(addr | ~PMD_MASK, pvmw->vma->vm_end - 1) + 1; + start = max(addr & PMD_MASK, vma->vm_start); + end = min(addr | ~PMD_MASK, vma->vm_end - 1) + 1; if (end - start > MIN_LRU_BATCH * PAGE_SIZE) { if (addr - start < MIN_LRU_BATCH * PAGE_SIZE / 2) @@ -3998,7 +4003,7 @@ void lru_gen_look_around(struct page_vma unsigned long pfn; pte_t ptent = ptep_get(pte + i); - pfn = get_pte_pfn(ptent, pvmw->vma, addr); + pfn = get_pte_pfn(ptent, vma, addr); if (pfn == -1) continue; @@ -4009,7 +4014,7 @@ void lru_gen_look_around(struct page_vma if (!folio) continue; - if (!ptep_test_and_clear_young(pvmw->vma, addr, pte + i)) + if (!ptep_test_and_clear_young(vma, addr, pte + i)) VM_WARN_ON_ONCE(true); young++; _ Patches currently in -mm which might be from yuzhao@google.com are