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([23.254.208.9]) by smtp.gmail.com with ESMTPSA id a92af1059eb24-169a442956asm12850045c88.16.2026.10.09.19.36.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 09 Oct 2026 19:36:13 -0700 (PDT) From: Qiliang Yuan To: Ming Lei , Jens Axboe , Nilay Shroff , Hannes Reinecke Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, stable@vger.kernel.org Subject: Re: [PATCH] block: don't quiesce the queue when setting the default elevator Date: Sat, 10 Oct 2026 10:36:07 +0800 Message-ID: <20261010023608.3667184-1-odys.yuan@gmail.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20261001-bug-block-elevator-init-quiesce-v1-1-5c85fa0ec59b@gmail.com> References: <20261001-bug-block-elevator-init-quiesce-v1-1-5c85fa0ec59b@gmail.com> Precedence: bulk X-Mailing-List: linux-block@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 Ming, Jens, Gentle ping. Since 1e44bedbc921 ("block: unifying elevator change"), setting the default elevator quiesces the queue again, which 245a489e81e1 had avoided, so every disk added with a default elevator waits for an RCU grace period. START_DEV of a single-queue ublk device takes 7.74ms at p50 instead of 0.68ms. Ming, as the author of 1e44bedbc921, could you take a look when you have a moment? Thanks, Qiliang