{"id":2230787,"url":"http://patchwork.ozlabs.org/api/1.1/patches/2230787/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20260430040427.4672-6-baohua@kernel.org/","project":{"id":2,"url":"http://patchwork.ozlabs.org/api/1.1/projects/2/?format=json","name":"Linux PPC development","link_name":"linuxppc-dev","list_id":"linuxppc-dev.lists.ozlabs.org","list_email":"linuxppc-dev@lists.ozlabs.org","web_url":"https://github.com/linuxppc/wiki/wiki","scm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git","webscm_url":"https://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux.git/"},"msgid":"<20260430040427.4672-6-baohua@kernel.org>","date":"2026-04-30T04:04:27","name":"[v2,5/5] mm/filemap: Avoid retrying page faults on uptodate folios in filemap faults","commit_ref":null,"pull_url":null,"state":"handled-elsewhere","archived":false,"hash":"6ef5172c9d44c8efcbb9fdb6a57172b799cdccaa","submitter":{"id":48512,"url":"http://patchwork.ozlabs.org/api/1.1/people/48512/?format=json","name":"Barry Song","email":"baohua@kernel.org"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linuxppc-dev/patch/20260430040427.4672-6-baohua@kernel.org/mbox/","series":[{"id":502184,"url":"http://patchwork.ozlabs.org/api/1.1/series/502184/?format=json","web_url":"http://patchwork.ozlabs.org/project/linuxppc-dev/list/?series=502184","date":"2026-04-30T04:04:27","name":"mm: reduce mmap_lock contention and improve page fault performance","version":2,"mbox":"http://patchwork.ozlabs.org/series/502184/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2230787/comments/","check":"success","checks":"http://patchwork.ozlabs.org/api/patches/2230787/checks/","tags":{},"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linuxppc-dev@lists.ozlabs.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=kernel.org header.i=@kernel.org header.a=rsa-sha256\n header.s=k20201202 header.b=ocBfK8O4;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org\n (client-ip=2404:9400:21b9:f100::1; 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a=rsa-sha256; c=relaxed/simple; d=kernel.org;\n\ts=k20201202; t=1777521919;\n\tbh=pbXcAk16+rZv3mixELQ0Ipha1GpoRaVFtegxsWu8Zqk=;\n\th=From:To:Cc:Subject:Date:In-Reply-To:References:From;\n\tb=ocBfK8O4Ywas1DnfVulkPf8JAygFLLLSXfSSIhFab5aPydgPGyQRMZl4VC0fcDxzh\n\t ZSF8ZjBo9bGMKXhwl/M9RckUdNTcuoEDs1sQYC8HxwbacO47214ueIB5PuN5R9qPyl\n\t 7/vXQCjK6DhEeLKCFGPA8mBl5pi8Xir7/uhc151Nze4/YpDG2oez+rIhbMYqevbaCB\n\t eLjkznrbZrf9uMIIMqF0/apYtZGMqURcRmb3l4AFBitMcYEDgyMeHrj8n9yVB0vf4O\n\t no7KHvYOh/5gIxhaiyHe3dpMaQbh59rmzxY6J3CuNafpQ/IRafc5BIkfCVPTmXqOYt\n\t bTDK/08BVuABA==","From":"\"Barry Song (Xiaomi)\" ","To":"akpm@linux-foundation.org,\n\tlinux-mm@kvack.org,\n\twilly@infradead.org","Cc":"david@kernel.org,\n\tljs@kernel.org,\n\tliam@infradead.org,\n\tvbabka@kernel.org,\n\trppt@kernel.org,\n\tsurenb@google.com,\n\tmhocko@suse.com,\n\tjack@suse.cz,\n\tpfalcato@suse.de,\n\twanglian@kylinos.cn,\n\tchentao@kylinos.cn,\n\tlianux.mm@gmail.com,\n\tkunwu.chan@gmail.com,\n\tliyangouwen1@oppo.com,\n\tchrisl@kernel.org,\n\tkasong@tencent.com,\n\tshikemeng@huaweicloud.com,\n\tnphamcs@gmail.com,\n\tbhe@redhat.com,\n\tyoungjun.park@lge.com,\n\tlinux-arm-kernel@lists.infradead.org,\n\tlinux-kernel@vger.kernel.org,\n\tloongarch@lists.linux.dev,\n\tlinuxppc-dev@lists.ozlabs.org,\n\tlinux-riscv@lists.infradead.org,\n\tlinux-s390@vger.kernel.org,\n\t\"Barry Song (Xiaomi)\" ","Subject":"[PATCH v2 5/5] mm/filemap: Avoid retrying page faults on uptodate\n 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>","X-Mailing-List":"linuxppc-dev@lists.ozlabs.org","List-Id":"","List-Help":"","List-Owner":"","List-Post":"","List-Archive":",\n ","List-Subscribe":",\n ,\n ","List-Unsubscribe":"","Precedence":"list","MIME-Version":"1.0","Content-Transfer-Encoding":"8bit","X-Spam-Status":"No, score=-0.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED,\n\tDKIM_VALID,DKIM_VALID_AU,DKIM_VALID_EF,SPF_HELO_NONE,SPF_PASS\n\tautolearn=disabled version=4.0.1 OzLabs 8","X-Spam-Checker-Version":"SpamAssassin 4.0.1 (2024-03-25) on lists.ozlabs.org"},"content":"For uptodate folios, we are not waiting on I/O. We should\nbe able to acquire the folio lock shortly, so there is no\nneed to drop per-vma locks and perform a full PF retry.\n\nSigned-off-by: Barry Song (Xiaomi) \n---\n mm/filemap.c | 7 +++++++\n 1 file changed, 7 insertions(+)","diff":"diff --git a/mm/filemap.c b/mm/filemap.c\nindex b532d6cbafc8..0d2f6af5d0fe 100644\n--- a/mm/filemap.c\n+++ b/mm/filemap.c\n@@ -3533,6 +3533,13 @@ vm_fault_t filemap_fault(struct vm_fault *vmf)\n \t\t}\n \t}\n \n+\t/*\n+\t * If the folio is uptodate, we are likely only waiting for\n+\t * another concurrent PTE mapping to complete, which should\n+\t * be brief. No need to drop the lock and retry the fault.\n+\t */\n+\tif (folio_test_uptodate(folio))\n+\t\tvmf->flags &= ~FAULT_FLAG_ALLOW_RETRY;\n \tif (!lock_folio_maybe_drop_mmap(vmf, folio, &fpin))\n \t\tgoto out_retry;\n \n","prefixes":["v2","5/5"]}