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 BF55E30CD9F; Fri, 29 Aug 2025 04:38:40 +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=1756442322; cv=none; b=CSzPDvC9JsKB4Lxb76vvvWdaOxlfE689QRBU+5zZRu1baitkl23R5skv3xaTdCfqFxPhgBhMkrcOMAgp0IxPlDX0HTtWteokBCZHFK4sjJjsbRqQqJ1rccdBijnkyS0nCDm1S/yKb6BJ17zfMLQiPOAShtahx23zBqYMJb0K4G8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1756442322; c=relaxed/simple; bh=kR47r7+cZe1DzINd4XA4apwTZcOc4Rqjsr0w0We2qGc=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=cbtRsQSLAJFCdKSXF0QGB7UxJKXbM/ZKgDDG0gjEA7NHbgijMjo0XdppBtlvfd5Qehe3Z3YVWzD0lGSG4igvoo9T7MdJ8tNE2Kd+NJ6MGYEaKeJf/hoxKalDpLGIORMbN0LysGbMthO6vexfUhhe97baGWFuC65yJYZe/is/mBI= 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=WI81Mo1b; 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="WI81Mo1b" Received: from localhost (localhost [127.0.0.1]) by 003.mia.mailroute.net (Postfix) with ESMTP id 4cClrv4V8tzltPtf; Fri, 29 Aug 2025 04:38:39 +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=1756442318; x=1759034319; bh=IaPSaBw2KwMcDI1oubljBKPZ 1q5dOYR2yWs8+LQ+2iw=; b=WI81Mo1bKW4UckaLrlytM6X1pG4i/tjylT1z99Aj d3dSbIyIN6+Uxvqozkc7LJk424zJ6Vxrn5h0xl8wJy4zZ7UH9FYhQMhOnYpiBO2m HVOvRf//3lNEsQc6sCg4j8LUIqCwhPSJTeWUHmqOLiS3G6dJKksyGVIBbsZa5/OC F1Yl4HXFqeEJnrUoMdVPstRBXiyBteu3SNyo0tixWe+zz552Qj5U20Vyk+MInxbO 0ZPnmO0SyXPUt0feYhsxLX8mJ3tWuEkJNiuwh6kSb91hGkuWrFH0ldCswaKwvC1c 4su4TZ9JgPAtpwsvF+/KtF9qZQljHF+2ci32a8OUrHg8Fg== 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 raeT_GyE74iU; Fri, 29 Aug 2025 04:38:38 +0000 (UTC) Received: from [172.20.6.188] (unknown [208.98.210.68]) (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 4cClrn3c1mzltM5Z; Fri, 29 Aug 2025 04:38:31 +0000 (UTC) Message-ID: <62c9b68f-6adc-41d8-b504-4bce4d721e64@acm.org> Date: Thu, 28 Aug 2025 21:38:24 -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: [PATCH] block/mq-deadline: Replace DD_PRIO_MAX with DD_PRIO_COUNT To: chengkaitao , axboe@kernel.dk Cc: linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, chengkaitao References: <20250829015444.91369-1-pilgrimtao@gmail.com> Content-Language: en-US From: Bart Van Assche In-Reply-To: <20250829015444.91369-1-pilgrimtao@gmail.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 8/28/25 6:54 PM, chengkaitao wrote: > diff --git a/block/mq-deadline.c b/block/mq-deadline.c > index b9b7cdf1d3c9..1a031922c447 100644 > --- a/block/mq-deadline.c > +++ b/block/mq-deadline.c > @@ -41,19 +41,16 @@ static const int fifo_batch = 16; /* # of sequential requests treated as o > enum dd_data_dir { > DD_READ = READ, > DD_WRITE = WRITE, > + DD_DIR_COUNT = 2 > }; > > -enum { DD_DIR_COUNT = 2 }; > - This change is not an improvement in my opinion because it makes it less clear what the role of DD_DIR_COUNT is. > enum dd_prio { > - DD_RT_PRIO = 0, > - DD_BE_PRIO = 1, > - DD_IDLE_PRIO = 2, > - DD_PRIO_MAX = 2, > + DD_RT_PRIO, > + DD_BE_PRIO, > + DD_IDLE_PRIO, There is code that depends on DD_RT_PRIO < DD_BE_PRIO < DD_IDLE_PRIO so I'd like to keep the explicit enum values. > + DD_PRIO_COUNT > }; > > -enum { DD_PRIO_COUNT = 3 }; I see the above change as a step backwards because it makes the role of DD_PRIO_COUNT less clear. > - for (prio = DD_BE_PRIO; prio <= DD_PRIO_MAX; prio++) { > + for (prio = DD_BE_PRIO; prio < DD_PRIO_COUNT; prio++) { The current code is easier to read IMHO than the new code. Thanks, Bart.