From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (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 489F870830 for ; Fri, 2 Jan 2026 01:14:31 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767316471; cv=none; b=TRYFG5+VLFp2XraQdJHDw8Tt9lhscUiO3JKHOCehi+mOFXRG0URneNZ/qDifNPgs01IWdFIdrQpv4RvN4lmHr+HD4FR3IE2RO2k8toIDyQRt6JL/6QfQqvkBEsQar0n3FCrJqyOZqsHR5g4u5OGe07iaO1Ui2fSO7uDIgPoJ3fA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1767316471; c=relaxed/simple; bh=KMkhhZqnKJNPiqcAnT3vvev0RqIlqkwlOye9cBSnPx4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=pOYAcYUzA4/Htrzf8+uXZaRelhfD2Jwh4NTDjNC6jvu2JMt/tQMsW22zwRffTWyV90iZ2WDnI8VcKcdoDxpqAowb+Brfdh9hYesjO54gl+o1wNG1hSy5fXMQcoM9JIh4bk96u4WOJ6jjzjOu2T9JRZt8tLPUtP2H3yNCOXURmWU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=mzOtUw1x; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="mzOtUw1x" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 34FE8C4CEF7; Fri, 2 Jan 2026 01:14:30 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1767316470; bh=KMkhhZqnKJNPiqcAnT3vvev0RqIlqkwlOye9cBSnPx4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=mzOtUw1x/74dGSRSvgxB7e9OeoolqV/0Q2RdajNSlZFqeKumBdnssfau1e0oC/4Jp 6lkO1BS4RcgB6KXAhRlLl1aqA3I1aPxNaZim6wkY+PTaAkURsWsd2lRZP186kMQOHM iXIN8wQ6jbNNnnaPco+1M7fnzDs9iYJDhePs6kiu9SVciyyR0m/Myb/7lkPPRhFQz/ 6gO9pUEfzmFeHOptcytE2eNCtIAXzk+neAJxQVGedKFPVZ2cjDZxIXEMQcdLqTgmKg 0TlF+z5z8YJEjIXsBEsqo3P33/aqIQOJPDeVxIC8/jrgXvL7FQtb/Vf4M3/Sjzn9Ck KncjnOvZMDAkA== Message-ID: <1b279430-e3e7-4712-9c21-c8d4da43d34a@kernel.org> Date: Fri, 2 Jan 2026 10:14:29 +0900 Precedence: bulk X-Mailing-List: linux-ide@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH v3 0/2] Prevent non-NCQ command starvation To: Niklas Cassel Cc: linux-ide@vger.kernel.org, Igor Pylypiv , Xingui Yang , John Garry References: <20251220002140.148854-1-dlemoal@kernel.org> Content-Language: en-US From: Damien Le Moal Organization: Western Digital Research In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 12/31/25 19:04, Niklas Cassel wrote: > On Sat, Dec 20, 2025 at 09:21:38AM +0900, Damien Le Moal wrote: >> This small patch series addresses potential command starvation issues >> with non-NCQ passthrough commands issued to a device accessed through > > Here and everywhere else: > s/non-NCQ passthrough commands/non-NCQ commands/ > > The problem is really not related to passthrough commands, > but rather the mix between NCQ and non-NCQ commands. > > E.g. you can perform a ioctl with the REQ_OP_DISCARD command, > for most ATA devices this is a SCSI WRITE SAME 16 CMD, which gets > translated to either a NCQ or non-NCQ command depending on if the > device supports NCQ encapsulated Data Set Management (DSM) commands, > and specifically if the device has the QUEUED DATA SET MANAGEMENT > SUPPORTS TRIM bit set or not, which is not a given. > > TL;DR: the starvation problem is not directly tied to non-NCQ > passthrough commands, but any command, even commands that goes via > the block layer, that happens to be translated to a non-NCQ command. Yep. I corrected that. -- Damien Le Moal Western Digital Research