From mboxrd@z Thu Jan 1 00:00:00 1970 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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id CE046D29FB0 for ; Thu, 4 Dec 2025 19:07:08 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Content-Transfer-Encoding: Content-Type:In-Reply-To:From:References:Cc:To:Subject:MIME-Version:Date: Message-ID:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=Sxd/Aif4YOWMwisvLZs1jz8UDO3+wD2UJitwu5+0+40=; b=mIxkpO8kLX9GVuruPVt3XwCcOA k7Rd6giJN/1rSrTrV5ZIgC9xQFiB4W9OkyhVMObfLzB+qqSeJdC2e2q3oObPkggQKRzxz2C/yJDaU raSF+oKCewvUIz8wurEx2eLbePduIH6F2fRYxeFgQFW66Cvmk9crj3JwqlGjwMQhr2aKgG/EB27tX 2qO4kk9I2LH7kgW7WmpuDBw4iSqfc3n1O8W+gl4sXTsCxVxFQeAMwGkTkxwTp0iquux4W1Pn32Jty tJsZKzzj0FKqO2+QPQWQ+/kHWSZ+kQigFx5ULy2TtFwfn0kinlKQ1t8K3fTVSj2FsCBMFZr758NML jw/sA2IQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1vREfT-00000008TsQ-0p2e; Thu, 04 Dec 2025 19:07:07 +0000 Received: from 013.lax.mailroute.net ([199.89.1.16]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1vREfR-00000008Ts2-19E7 for linux-nvme@lists.infradead.org; Thu, 04 Dec 2025 19:07:06 +0000 Received: from localhost (localhost [127.0.0.1]) by 013.lax.mailroute.net (Postfix) with ESMTP id 4dMkX86PqhzlxWdb; Thu, 4 Dec 2025 19:07:04 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=acm.org; h= content-transfer-encoding:content-type:content-type:in-reply-to :from:from:content-language:references:subject:subject :user-agent:mime-version:date:date:message-id:received:received; s=mr01; t=1764875221; x=1767467222; bh=Sxd/Aif4YOWMwisvLZs1jz8U DO3+wD2UJitwu5+0+40=; b=aA1XOYX6RSpT8owyMnR+f1C+LVSP+WXgI1mbf7U1 VrBv+EyKudu3LzWT4/8cbIKwlh5fDVdw9JAWqpGAmJTBVTsgMcLy9OmdUu//t++O qjwyEI44j0fwfKecnwTZRVmDsQevOKrqPHi1pV0RsCZZTQZG7QcR/p8FlnKVbPd8 vq7V9h+fib6qOGIjfhcDa85m4m6HGtw5vQGhg5qshMz68C8SCSqBWQHAoGM4x6cY ax6373nIg3XTHMBkuKRag5EdcTFxv/i2HEs0+hAGdTesyeR+7x6EXBzta8aJfKkH Op1rg+VbxTry6veh8LgpD52p85pKpxLUs+AHfpRsK4YiQw== X-Virus-Scanned: by MailRoute Received: from 013.lax.mailroute.net ([127.0.0.1]) by localhost (013.lax [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id JGOgnh3WSgQO; Thu, 4 Dec 2025 19:07:01 +0000 (UTC) Received: from [10.22.10.72] (syn-098-153-230-237.biz.spectrum.com [98.153.230.237]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) (Authenticated sender: bvanassche@acm.org) by 013.lax.mailroute.net (Postfix) with ESMTPSA id 4dMkWt4TLVzlfdfW; Thu, 4 Dec 2025 19:06:49 +0000 (UTC) Message-ID: <71e9950f-ace7-4570-a604-ceca347eea20@acm.org> Date: Thu, 4 Dec 2025 09:06:47 -1000 MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 1/1] block: Use RCU in blk_mq_[un]quiesce_tagset() instead of set->tag_list_lock To: Mohamed Khalfella Cc: Chaitanya Kulkarni , Christoph Hellwig , Jens Axboe , Keith Busch , Sagi Grimberg , Casey Chen , Yuanyuan Zhong , Hannes Reinecke , Ming Lei , Waiman Long , Hillf Danton , linux-nvme@lists.infradead.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org References: <20251204181212.1484066-1-mkhalfella@purestorage.com> <20251204181212.1484066-2-mkhalfella@purestorage.com> <5450d3fa-3f00-40ae-ac95-1f08886de3b6@acm.org> <20251204184243.GZ337106-mkhalfella@purestorage.com> Content-Language: en-US From: Bart Van Assche In-Reply-To: <20251204184243.GZ337106-mkhalfella@purestorage.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20251204_110705_336828_B8F41BF2 X-CRM114-Status: GOOD ( 10.30 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On 12/4/25 8:42 AM, Mohamed Khalfella wrote: > Is blk_mq_del_queue_tag_set() performance sensitive such that it can not > take synchronize_rcu()? It is not in IO codepath, right? Introducing a new synchronize_rcu() call almost always slows down some workload so it should be avoided if possible. > I can not think of an easy way to do that. Suggestions are welcomed. I can't find the implementation of nvme_dev_disable_locked(). What kernel tree does your patch apply to? $ git grep -w nvme_dev_disable_locked axboe-block/for-next | wc -l 0 Thanks, Bart.