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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 X-Stat-Signature: h7jyx53ejrww6yest4uwf5no4m6mywiq X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: C63A7100006 X-Rspam-User: X-HE-Tag: 1687424252-913621 X-HE-Meta: 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 2L8se6N7 JutFgmu3fWaj0/m1odl4ap6KBM9Fs6VkeuUd44Sc2TsufXrvcJFRNvJVhlk2qmpxeP7TZoSe+4GatbTqVRnXQV4/KmJ08YV2acjfb9+4Pm5HahS1RgPWSHl/tu8sHEIycfXl79UCROKrdyUz36PjqcmnwIgfarSc1jh3K364rCRhbR0WMXGJZmyCC28CM9EWNAU6ASu6cTvX4v0iujHBiV+bPMCUQfU6z1DuS3uLQN52DayL83gX3z0aGhEffya2ZaO5mRKHb20vYTpbN7RrRuWzJpkD89+tddORT7AUk/1wqS5qR6Zq8is295/X4FTcfHR7ZOsPk3Ui4FXKHTY7gFCob9+7XUmCQye7Dm9VyzmYWXySbEizs2l5cHVroxHt/cprIbk0dci8lakSNme0j5W8sFdpz7HEESpyO X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: 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;