From mboxrd@z Thu Jan 1 00:00:00 1970 From: Waiman Long Subject: [PATCH v6 0/3] blk-cgroup: Optimize blkcg_rstat_flush() Date: Thu, 2 Jun 2022 15:20:17 -0400 Message-ID: <20220602192020.166940-1-longman@redhat.com> Mime-Version: 1.0 Content-Transfer-Encoding: 8bit Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1654197647; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding; bh=sUxMFBKWaF9vGh8gLEcG6jV1Ek/oQgsX0FVxKot2COA=; b=W/ezvFq0h7i/L/uv/u5qGwgOwwGMX9OkHr/gDQ/uIUiOrnf3bRaN7ThhT8MiLhN0HMHPMk Uaxlj3FtnpLPsqyTykEDWnXQXMOP3xJjFXbjPwLcvrih+WM/q5uUk5eeh7R/SjQ1GgkAQ3 qYVBOxMVG0C/jhWkbsxU1MjzBJahtYk= List-ID: Content-Type: text/plain; charset="us-ascii" To: Tejun Heo , Jens Axboe Cc: cgroups-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-block-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Ming Lei , Waiman Long v6: - Add a missing free_percpu() into blkcg_css_free() in patch 3. - Integrating the documentation patch 4 back into patch 3. v5: - Add a new patch 2 to eliminate the use of intermediate "ret" variable in blkcg_css_alloc() to fix compilation warning reported by kernel test robot. v4: - Update comment and eliminate "inline" keywords as suggested by TJ. v3: - Update comments in patch 2. - Put rcu_read_lock/unlock() in blkcg_rstat_flush(). - Use READ_ONCE/WRITE_ONCE() to access lnode->next to reduce data races. - Get a blkg reference when putting into the lockless list and put it back when removed. This patch series improves blkcg_rstat_flush() performance by eliminating unnecessary blkg enumeration and flush operations for those blkg's and blkg_iostat_set's that haven't been updated since the last flush. Waiman Long (3): blk-cgroup: Correctly free percpu iostat_cpu in blkg on error exit blk-cgroup: Return -ENOMEM directly in blkcg_css_alloc() error path blk-cgroup: Optimize blkcg_rstat_flush() block/blk-cgroup.c | 119 +++++++++++++++++++++++++++++++++++++++------ block/blk-cgroup.h | 9 ++++ 2 files changed, 112 insertions(+), 16 deletions(-) -- 2.31.1