From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from 003.mia.mailroute.net (003.mia.mailroute.net [199.89.3.6]) (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 0E22A299959; Mon, 17 Nov 2025 23:45:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=199.89.3.6 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763423147; cv=none; b=d8js+TXCwef4gmedxiIfwuyojxxZIXvv44JxYdewXxVPsECsdPni+xtko9+MgaO0GyhA+Y832zxEcr9FPTQdwpfNcKUe8veDeFmwoegjXD3pThnmUgo2V0/bG5kBkg0M+suDYIHUZtgL+LMMTU1aW1R21qee9Jm+u4PHwBNiuGw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763423147; c=relaxed/simple; bh=fSrzL469rq5UJzLY4Y4dspONxGp76B9Lzl8uRfX2Kgw=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Iot8XtrGt9Doifnit2nJXoPsDJL9k25vs2ci0utkpzi6z82Iep0OVwVtgGSs+GSdQnDBAjK08euU/P+j/sJemd55GM0eNaQz9R/FtZ1QKKIw+tSgXeD0ThAQ5v/ZlJFRrtRROs/gNIwqGjmZBxEakBSud/TO42t8TFNgYBE2RO4= 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=rGm8wVAv; arc=none smtp.client-ip=199.89.3.6 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="rGm8wVAv" Received: from localhost (localhost [127.0.0.1]) by 003.mia.mailroute.net (Postfix) with ESMTP id 4d9PWY14pmzlv4Vf; Mon, 17 Nov 2025 23:45:45 +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=1763423143; x=1766015144; bh=1r2Y5HDZXyyu9gW8fJQLxunD SDvVTAJBOoNfsdF76+s=; b=rGm8wVAvhz1db70SLSJ0XPdnbZwzBxUAizLkdS16 b8Jec5uRrqoa2jc5txFLl2HEGsLYM3pLYdY5EbQeAg0T0zG9qQSXtm8NCiPrCOMB J4q5JDoluaCca3oJgtmfsT2inyR/LyDs4TR+cp3OGcNQnkWEWex3irVDeYewgJ82 DSSFjp4QSzP/U70zctr93yFwQtp9GBrDlSgZKG7OZPHmxrR/S6MHWzc/b/1bLynu FR7mpDblJeOllyL12ucHJT14LsTrKYHSTG8Jd2o2BJbaQ6E9ilBQSuLfPpfDDcB7 V0WKB6jHoFuW9W3jm2vWKvHy3mTAw8ZRWmhuHA+npSMYTw== X-Virus-Scanned: by MailRoute Received: from 003.mia.mailroute.net ([127.0.0.1]) by localhost (003.mia [127.0.0.1]) (mroute_mailscanner, port 10029) with LMTP id DtIn5_1UyuaN; Mon, 17 Nov 2025 23:45:43 +0000 (UTC) Received: from [100.119.48.131] (unknown [104.135.180.219]) (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 003.mia.mailroute.net (Postfix) with ESMTPSA id 4d9PWM1xQqzlv4Dp; Mon, 17 Nov 2025 23:45:33 +0000 (UTC) Message-ID: <4f3ed928-2fef-469d-8bfc-76041267b1c6@acm.org> Date: Mon, 17 Nov 2025 15:45:32 -0800 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 RESEND v5 3/7] blk-mq: add a new queue sysfs attribute async_depth To: Yu Kuai , axboe@kernel.dk, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org Cc: nilay@linux.ibm.com References: <20251116035228.119987-1-yukuai@fnnas.com> <20251116035228.119987-4-yukuai@fnnas.com> Content-Language: en-US From: Bart Van Assche In-Reply-To: <20251116035228.119987-4-yukuai@fnnas.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 11/15/25 7:52 PM, Yu Kuai wrote: > +static void blk_mq_limit_depth(struct blk_mq_alloc_data *data) > +{ > + struct elevator_mq_ops *ops; > + > + /* If elevator is none, don't limit requests */ Nobody calls an I/O scheduler an elevator anymore. So I propose to change "elevator is none" into "no I/O scheduler has been configured". > + /* > + * Flush/passthrough requests are special and go directly to the > + * dispatch list, they don't have limit. > + */ "they don't have a limit" -> "are not subject to the async_depth limit". > + /* > + * By default, sync requests have no limit, and async requests is > + * limited to async_depth. > + */ "is" -> "are" > - /* > - * All requests use scheduler tags when an I/O scheduler is > - * enabled for the queue. > - */ > - data->rq_flags |= RQF_SCHED_TAGS; Why has the above comment been removed? I think that it is useful. Additionally, please split this patch into two patches: a first patch that introduces the function blk_mq_limit_depth() and a second patch with the remaining changes from this patch. Thanks, Bart.