From patchwork Thu Jun 22 08:53:32 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Qi Zheng X-Patchwork-Id: 13288782 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 0FBFBC0015E for ; Thu, 22 Jun 2023 09:06:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231971AbjFVJGI (ORCPT ); Thu, 22 Jun 2023 05:06:08 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47464 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232069AbjFVJEt (ORCPT ); Thu, 22 Jun 2023 05:04:49 -0400 Received: from mail-pl1-x632.google.com (mail-pl1-x632.google.com [IPv6:2607:f8b0:4864:20::632]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 90A2149EF for ; Thu, 22 Jun 2023 01:58:12 -0700 (PDT) Received: by mail-pl1-x632.google.com with SMTP id d9443c01a7336-1b693afe799so2466825ad.1 for ; Thu, 22 Jun 2023 01:58:12 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=bytedance.com; s=google; t=1687424252; x=1690016252; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:from:to:cc:subject:date :message-id:reply-to; bh=YpqAnPCFjvBxCUJyQNRij7IdVYJH6Jib7EICYqtSs4Q=; b=I9WP6mv1rDRCGtgaLzA9lhBXeFPAHaj8y0iyY2DOjVEWCsT2F7nfNJVwyIikm+kMao zO6QJGdxbeP+Xd2yLUuD3B5OfZQRm3B4q5mm2BLvCFNnuFgYbDreBXTpY911jw5PjLjw 5qBcX7//daeu9fw2bM5v9uWJQ3Yj963JAAdMROcF9Ug6KJW+BwPKjtr4qnEx+svXyNj4 WQtBJXjBe1rX51UFB2Mb+BbnprNNOvKWLYHk9IXF69UQEETABYtrhl0ZHyku4x/+376s ovmIBUSgYXrVJUG8L2WcJE6QBBiCJCq44tzgQbbUxJYU3EpXiLR3t2TzR3wvfdUTA7wG r7SA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1687424252; x=1690016252; h=content-transfer-encoding:mime-version:references:in-reply-to :message-id:date:subject:cc:to:from:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=YpqAnPCFjvBxCUJyQNRij7IdVYJH6Jib7EICYqtSs4Q=; b=jxSEcUWfhlRpAmMdt1qt1BG81KNOl1fDVx2Puo5S79vq5nwuBTUWkgQY7ULOPEDZCf E2J2Q8mpxUyPJOFJlByS792n9ZweGbV74otpuJ1LMtJWtFhQXpfEpGZLcohgzAvxURtN TEbZt+EFCNABxlgjz9L+OvpJRWOBqI+hGXVp6F0LBNO7KT0r769Zf2OEy1sH6skjwQgt Gy/8/+58LYPEViFJsoaSNKHtM+o9JKDnJqzgkWydmdyrh80jhzRCRv0gR7raUEowPQgQ iyJ4jEtlCMvGZ7MyTT8aepq6/buRrLKhLBVTFTos74/LS3FGi6Naa8Su2Z/5gcFl6U2p Qczg== X-Gm-Message-State: AC+VfDy7fx53HF54CABBqAmAwJTIvIQOlBMrVjbZJ3ZuHkTvYusoUFGU k+TVj4tgJJ2hC/GTNWAwv7IU9g== X-Google-Smtp-Source: ACHHUZ6FoF5W+f0N2ZUpFBUVBh1vs3Mj6G9dcM80ve0PhcTP+4niqZQRBrFmYJGvwbhs9MGB3E6MuA== X-Received: by 2002:a17:903:32c4:b0:1b3:e352:6d88 with SMTP id i4-20020a17090332c400b001b3e3526d88mr21673124plr.6.1687424251794; Thu, 22 Jun 2023 01:57:31 -0700 (PDT) Received: from C02DW0BEMD6R.bytedance.net ([139.177.225.254]) by smtp.gmail.com with ESMTPSA id h2-20020a170902f7c200b001b549fce345sm4806971plw.230.2023.06.22.01.57.24 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 22 Jun 2023 01:57:31 -0700 (PDT) From: Qi Zheng To: akpm@linux-foundation.org, david@fromorbit.com, tkhai@ya.ru, vbabka@suse.cz, roman.gushchin@linux.dev, djwong@kernel.org, brauner@kernel.org, paulmck@kernel.org, tytso@mit.edu Cc: linux-kernel@vger.kernel.org, linux-mm@kvack.org, intel-gfx@lists.freedesktop.org, dri-devel@lists.freedesktop.org, linux-arm-msm@vger.kernel.org, dm-devel@redhat.com, linux-raid@vger.kernel.org, linux-bcache@vger.kernel.org, virtualization@lists.linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-nfs@vger.kernel.org, linux-xfs@vger.kernel.org, linux-btrfs@vger.kernel.org, Qi Zheng Subject: [PATCH 26/29] mm: shrinker: make count and scan in shrinker debugfs lockless Date: Thu, 22 Jun 2023 16:53:32 +0800 Message-Id: <20230622085335.77010-27-zhengqi.arch@bytedance.com> X-Mailer: git-send-email 2.24.3 (Apple Git-128) In-Reply-To: <20230622085335.77010-1-zhengqi.arch@bytedance.com> References: <20230622085335.77010-1-zhengqi.arch@bytedance.com> MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org Like global and memcg slab shrink, also make count and scan operations in memory shrinker debugfs lockless. The debugfs_remove_recursive() will wait for debugfs_file_put() to return, so there is no need to call rcu_read_lock() before calling shrinker_try_get(). Signed-off-by: Qi Zheng --- mm/shrinker_debug.c | 12 ++++++------ 1 file changed, 6 insertions(+), 6 deletions(-) diff --git a/mm/shrinker_debug.c b/mm/shrinker_debug.c index 3ab53fad8876..c18fa9b6b7f0 100644 --- a/mm/shrinker_debug.c +++ b/mm/shrinker_debug.c @@ -55,8 +55,8 @@ static int shrinker_debugfs_count_show(struct seq_file *m, void *v) if (!count_per_node) return -ENOMEM; - ret = down_read_killable(&shrinker_rwsem); - if (ret) { + ret = shrinker_try_get(shrinker); + if (!ret) { kfree(count_per_node); return ret; } @@ -92,7 +92,7 @@ static int shrinker_debugfs_count_show(struct seq_file *m, void *v) } while ((memcg = mem_cgroup_iter(NULL, memcg, NULL)) != NULL); rcu_read_unlock(); - up_read(&shrinker_rwsem); + shrinker_put(shrinker); kfree(count_per_node); return ret; @@ -146,8 +146,8 @@ static ssize_t shrinker_debugfs_scan_write(struct file *file, return -EINVAL; } - ret = down_read_killable(&shrinker_rwsem); - if (ret) { + ret = shrinker_try_get(shrinker); + if (!ret) { mem_cgroup_put(memcg); return ret; } @@ -159,7 +159,7 @@ static ssize_t shrinker_debugfs_scan_write(struct file *file, shrinker->scan_objects(shrinker, &sc); - up_read(&shrinker_rwsem); + shrinker_put(shrinker); mem_cgroup_put(memcg); return size;