From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 008.lax.mailroute.net (008.lax.mailroute.net [199.89.1.11]) (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 7D046188A29; Fri, 23 Aug 2024 14:12:34 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=199.89.1.11 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724422356; cv=none; b=oHTMsGwk9Xk6BgA2sjenm0cl5BOaf6Ltg9JDWbj0xMRo7/cDe4YBo/LZfuVCgQ1oYT5EGURF3AiMqfEEGhu102lRQx8Y5J5+OjJrPx1DiKUUQQTuibXZrJLqVAXNLi4vj31IQAl9YlOM7KGciQ6aKS0nBL6fJOv7ichSZDCc/Z4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1724422356; c=relaxed/simple; bh=EyufYXPNWSItb39u8DvxH833MSOIXo+lqAb2BqrMdbo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=dll/otl5VXBG7x5crO1x+oBwwn59R09jbl7xaFgdmW1ObaWnLyTqclkWTPVEpcaAkEEJMlgimU9jxsAHjq+cAwfFMtUE66CBjxR0dgxjzBxltWkO735mvBfoLFIJpQUm2DFjaijk7TWOhqq3Zgfj9rgzd1qqOwbyYgUTcZNEjLE= 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=JEMFW/8d; arc=none smtp.client-ip=199.89.1.11 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="JEMFW/8d" Received: from localhost (localhost [127.0.0.1]) by 008.lax.mailroute.net (Postfix) with ESMTP id 4Wr28D203jz6ClY9T; Fri, 23 Aug 2024 14:12:28 +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=1724422339; x=1727014340; bh=ONVrc9T6Yvt4FzO9QEqjvKtc SJZtTbp8nfkejbWKyo0=; b=JEMFW/8dza0fpv/dw2t0qZsrpqJvyK3ZqSw5SsPD we9w3NBPZk/3G6JcV60K0kuY0v+snOmDPkxfxeT1n2ssT7F+r2xSDZyT2Gn6XEp1 EcaQYHUvMRl8ZLFXAosOESxec+RkmVbCOlLKCCGg6DAoOMED9yzIwClPK4MkL9dW Gos9uzlvJYONbK9cvD0nXlt7pqL1i26Jt2o9Usn7kvsvFV/rrVNmR9wcyWY57C8I I/7refltH3d8d++NE8LFEL33bQ5VYViD9URUtJql/O0cxhsSqy6NT0blQBQll/V7 ntmhD/JDzUYdTgPLYkZhFdbKUppPKv38n0alsoL2p4W/nQ== X-Virus-Scanned: by MailRoute Received: from 008.lax.mailroute.net ([127.0.0.1]) by localhost (008.lax [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id MsMJKyLsDZkK; Fri, 23 Aug 2024 14:12:19 +0000 (UTC) Received: from [192.168.51.14] (c-73-231-117-72.hsd1.ca.comcast.net [73.231.117.72]) (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 008.lax.mailroute.net (Postfix) with ESMTPSA id 4Wr27z68t3z6ClY9F; Fri, 23 Aug 2024 14:12:15 +0000 (UTC) Message-ID: <340f156b-0dbb-45d2-a6dd-31e468ead846@acm.org> Date: Fri, 23 Aug 2024 07:12:13 -0700 Precedence: bulk X-Mailing-List: linux-block@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: Regarding patch "block/blk-mq: Don't complete locally if capacities are different" To: MANISH PANDEY , Christian Loehle , Sandeep Dhavale , Dietmar Eggemann Cc: Qais Yousef , axboe@kernel.dk, mingo@kernel.org, peterz@infradead.org, vincent.guittot@linaro.org, linux-block@vger.kernel.org, sudeep.holla@arm.com, Jaegeuk Kim , Christoph Hellwig , kailash@google.com, tkjos@google.com, bvanassche@google.com, quic_nitirawa@quicinc.com, quic_cang@quicinc.com, quic_rampraka@quicinc.com, quic_narepall@quicinc.com, "linux-kernel@vger.kernel.org" References: <10c7f773-7afd-4409-b392-5d987a4024e4@quicinc.com> <3feb5226-7872-432b-9781-29903979d34a@arm.com> <20240805020748.d2tvt7c757hi24na@airbuntu> <25909f08-12a5-4625-839d-9e31df4c9c72@acm.org> <1d9c27b2-77c7-462f-bde9-1207f931ea9f@quicinc.com> <17bf99ad-d64d-40ef-864f-ce266d3024c7@acm.org> <12a6f001-813e-4bc4-90c2-9f9ef7dc72e6@acm.org> <688ead11-c1c0-48b2-b4d1-feeb1278c692@quicinc.com> <1a95a60c-730a-4bb7-80c9-98b8a70f6521@acm.org> <66912a22-540d-4b9a-bd06-cce55b9ad304@quicinc.com> <3d37e8ba-25a8-45c2-93a3-02888dad2c9e@arm.com> <22d1bd64-934f-49f1-bb82-1367f4a43f40@quicinc.com> Content-Language: en-US From: Bart Van Assche In-Reply-To: <22d1bd64-934f-49f1-bb82-1367f4a43f40@quicinc.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 8/23/24 6:49 AM, MANISH PANDEY wrote: > while making the patch, i figured out that queue_flags is unsigned long > type and we already reached up to 32 flags as of now. Really? In Linus' master branch I see 13 queue flags. This is less than half of 32. From include/linux/blkdev.h: enum { QUEUE_FLAG_DYING, /* queue being torn down */ QUEUE_FLAG_NOMERGES, /* disable merge attempts */ QUEUE_FLAG_SAME_COMP, /* complete on same CPU-group */ QUEUE_FLAG_FAIL_IO, /* fake timeout */ QUEUE_FLAG_NOXMERGES, /* No extended merges */ QUEUE_FLAG_SAME_FORCE, /* force complete on same CPU */ QUEUE_FLAG_INIT_DONE, /* queue is initialized */ QUEUE_FLAG_STATS, /* track IO start and completion times */ QUEUE_FLAG_REGISTERED, /* queue has been registered to a disk */ QUEUE_FLAG_QUIESCED, /* queue has been quiesced */ QUEUE_FLAG_RQ_ALLOC_TIME, /* record rq->alloc_time_ns */ QUEUE_FLAG_HCTX_ACTIVE, /* at least one blk-mq hctx is active */ QUEUE_FLAG_SQ_SCHED, /* single queue style io dispatch */ QUEUE_FLAG_MAX }; Bart.