From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 011.lax.mailroute.net (011.lax.mailroute.net [199.89.1.14]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 14DA41DE894; Thu, 4 Dec 2025 18:22:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=199.89.1.14 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764872563; cv=none; b=PxLmuxFQzYurr74q0/M8FgazGbD1kA/gdFXoPBQJs1j15DhmZ4OuWamUBqHg8zIQ9RRnQUriOW0csMLzHZFeK7G/s7lwjfrWhlrLt5IIb6fAIV5TzdzQebekKHvPMPxNefr+cNcR4Gp02IoYl5KJdBHfmVtycdD9F1mZXEW5kR8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1764872563; c=relaxed/simple; bh=XlCuzaNUiyu4wnfTROGkhBHf6ZHXJIFTAaZ9hxvB6ck=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=WcqANrdTt6qVai1Fil1MTKyShHkokb3lF9OFTR+X613ujmqhoJFWFaqY4Ojp6vc4JVXBzlqYCEpRjNmPJl+zpKvxyigkBDWMAukgs33pEfQec9yoJlUDCa6WFIoreOiyNuNbW8iDtsFrPfH29O0MWRIR64x8HxCGVI657RqV74w= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org; spf=pass smtp.mailfrom=acm.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b=BDh8OEQM; arc=none smtp.client-ip=199.89.1.14 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=reject dis=none) header.from=acm.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=acm.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=acm.org header.i=@acm.org header.b="BDh8OEQM" Received: from localhost (localhost [127.0.0.1]) by 011.lax.mailroute.net (Postfix) with ESMTP id 4dMjXv3gMWz1XM0pg; Thu, 4 Dec 2025 18:22:39 +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=1764872556; x=1767464557; bh=uSt3LQxRGpjDmMgYwHR3vatY 0L+HSvxBS4jGX4ynEhY=; b=BDh8OEQMeMGOmbaMpaZ8cfAW7Vn13mFGdLUxghFQ qASqhrTIOH2eJF0gdpTuJAI4Vi/+WjasOSyUWWs1odHF8CYHxFFJ/GD1KPeldydw /Fe/pI90m6Q9jMY/W9j3ZF8313NMjZCNKaRBFC8y9OXY5doG6fTvem9QK2apU7lW G4JOuR9B0tcnmCfu5GsJf6TsziA9+sfMACyq7rjb6egFubDQexPNgRfc61n4zYRS EPDQxlvOz1GPgoWk+ULFd3YMtfQiQBthsLr6HixT+0LJtigha8TJ77HpO4foZkh5 mBqqoVEkJrjf1e7aUc3dhKa22d961cd43U6osr/NN+48Yw== X-Virus-Scanned: by MailRoute Received: from 011.lax.mailroute.net ([127.0.0.1]) by localhost (011.lax [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id FtvBUV3owpqd; Thu, 4 Dec 2025 18:22:36 +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 011.lax.mailroute.net (Postfix) with ESMTPSA id 4dMjXg1zTgz1XM0pF; Thu, 4 Dec 2025 18:22:26 +0000 (UTC) Message-ID: <5450d3fa-3f00-40ae-ac95-1f08886de3b6@acm.org> Date: Thu, 4 Dec 2025 08:22:23 -1000 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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 , Chaitanya Kulkarni , Christoph Hellwig , Jens Axboe , Keith Busch , Sagi Grimberg Cc: 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> Content-Language: en-US From: Bart Van Assche In-Reply-To: <20251204181212.1484066-2-mkhalfella@purestorage.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 12/4/25 8:11 AM, Mohamed Khalfella wrote: > @@ -4302,6 +4302,8 @@ static void blk_mq_del_queue_tag_set(struct request_queue *q) > blk_mq_update_tag_set_shared(set, false); > } > mutex_unlock(&set->tag_list_lock); > + > + synchronize_rcu(); > INIT_LIST_HEAD(&q->tag_set_list); > } Yikes. This change slows down all blk_mq_del_queue_tag_set() callers. Please fix the reported deadlock by modifying the NVMe code instead of slowing down the block layer. Thanks, Bart.