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([23.254.208.9]) by smtp.gmail.com with ESMTPSA id 5a478bee46e88-35c89429484sm21186597eec.23.2026.10.14.19.26.40 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 14 Oct 2026 19:26:42 -0700 (PDT) From: Qiliang Yuan To: Jens Axboe , Ming Lei Cc: Yu Kuai , Hannes Reinecke , "Martin K. Petersen" , "Paul E. McKenney" , linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/2] blk-mq: stop waiting for an SRCU grace period when freeing a tag set Date: Thu, 15 Oct 2026 10:26:37 +0800 Message-ID: <20261015022637.2973447-1-odys.yuan@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20261001-bug-blk-mq-global-tags-srcu-v1-0-e8415da10d1b@gmail.com> References: <20261001-bug-blk-mq-global-tags-srcu-v1-0-e8415da10d1b@gmail.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Jens, Ming, Gentle ping on this series. Paul acked it from the RCU side, and it still needs a look from the block side. Since I sent it, "ublk: drop the device reference outside ublk_ctl_mutex in DEL_DEV" has been applied to for-7.4/block, so ublk no longer frees tag sets under a global lock and the 19 s figure in the cover letter is out of date. The SRCU grace period that every blk_mq_free_tag_set() waits for is still there. With 4000 single-queue ublk devices on 7.3-rc5 plus that commit, median of 3 runs: without with this series DEL_DEV p50, serial 3.41ms 0.17ms deletion with 16 threads 4.17s 2.87s Thanks, Qiliang