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 287A319E839; Thu, 30 Apr 2026 04:05:19 +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=1777521920; cv=none; b=DiXndxxemP/308EwKpkY4C2jN6TfqdD6AYjCc/IE/eATtwdhFqUKASbpGDgdUROq66V5+zIV+aJuVBMasf9xyoPqCTXUORqapWoXn0kCDYOH46zsPdU4ZZkjk4y6EPIBxJQQpJBSux8d2thgX9pNte6neK7ysVfPEsuDxSvxuRE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1777521920; c=relaxed/simple; bh=pbXcAk16+rZv3mixELQ0Ipha1GpoRaVFtegxsWu8Zqk=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References: MIME-Version; b=g5K+6NjbuMbAAL9PPzmC8U+pksa3pl3diVTqlf5UKoEcVbwJ9hiszi6HDFeQrQNewX84XYtx6h48VlbQ/U4LweKTRY0EpgCiTirc5sNulMCpGbAcFPyMKkT1wLH4e2uK1pzXYnAKd1jcHCCrQssBhLmb8q0iw6iBvBtg9YuDIbU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=ocBfK8O4; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="ocBfK8O4" Received: by smtp.kernel.org (Postfix) with ESMTPSA id DC6E6C2BCB8; Thu, 30 Apr 2026 04:05:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1777521919; bh=pbXcAk16+rZv3mixELQ0Ipha1GpoRaVFtegxsWu8Zqk=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ocBfK8O4Ywas1DnfVulkPf8JAygFLLLSXfSSIhFab5aPydgPGyQRMZl4VC0fcDxzh ZSF8ZjBo9bGMKXhwl/M9RckUdNTcuoEDs1sQYC8HxwbacO47214ueIB5PuN5R9qPyl 7/vXQCjK6DhEeLKCFGPA8mBl5pi8Xir7/uhc151Nze4/YpDG2oez+rIhbMYqevbaCB eLjkznrbZrf9uMIIMqF0/apYtZGMqURcRmb3l4AFBitMcYEDgyMeHrj8n9yVB0vf4O no7KHvYOh/5gIxhaiyHe3dpMaQbh59rmzxY6J3CuNafpQ/IRafc5BIkfCVPTmXqOYt bTDK/08BVuABA== From: "Barry Song (Xiaomi)" To: akpm@linux-foundation.org, linux-mm@kvack.org, willy@infradead.org Cc: david@kernel.org, ljs@kernel.org, liam@infradead.org, vbabka@kernel.org, rppt@kernel.org, surenb@google.com, mhocko@suse.com, jack@suse.cz, pfalcato@suse.de, wanglian@kylinos.cn, chentao@kylinos.cn, lianux.mm@gmail.com, kunwu.chan@gmail.com, liyangouwen1@oppo.com, chrisl@kernel.org, kasong@tencent.com, shikemeng@huaweicloud.com, nphamcs@gmail.com, bhe@redhat.com, youngjun.park@lge.com, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, loongarch@lists.linux.dev, linuxppc-dev@lists.ozlabs.org, linux-riscv@lists.infradead.org, linux-s390@vger.kernel.org, "Barry Song (Xiaomi)" Subject: [PATCH v2 5/5] mm/filemap: Avoid retrying page faults on uptodate folios in filemap faults Date: Thu, 30 Apr 2026 12:04:27 +0800 Message-Id: <20260430040427.4672-6-baohua@kernel.org> X-Mailer: git-send-email 2.39.3 (Apple Git-146) In-Reply-To: <20260430040427.4672-1-baohua@kernel.org> References: <20260430040427.4672-1-baohua@kernel.org> Precedence: bulk X-Mailing-List: linux-s390@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit For uptodate folios, we are not waiting on I/O. We should be able to acquire the folio lock shortly, so there is no need to drop per-vma locks and perform a full PF retry. Signed-off-by: Barry Song (Xiaomi) --- mm/filemap.c | 7 +++++++ 1 file changed, 7 insertions(+) diff --git a/mm/filemap.c b/mm/filemap.c index b532d6cbafc8..0d2f6af5d0fe 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -3533,6 +3533,13 @@ vm_fault_t filemap_fault(struct vm_fault *vmf) } } + /* + * If the folio is uptodate, we are likely only waiting for + * another concurrent PTE mapping to complete, which should + * be brief. No need to drop the lock and retry the fault. + */ + if (folio_test_uptodate(folio)) + vmf->flags &= ~FAULT_FLAG_ALLOW_RETRY; if (!lock_folio_maybe_drop_mmap(vmf, folio, &fpin)) goto out_retry; -- 2.39.3 (Apple Git-146)