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 8F400349CC4; Fri, 10 Jul 2026 14:56:43 +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=1783695405; cv=none; b=O+lAvChEm6+9CjMTUj0ceSckQb3mCsGn+YrSaBh1kCmDtol4yF5CK7zrmF9aahKJBZ17jeoCgibpbS3O8X0HnY6o6BGPoOdI9mYxo/bX4znHCFXzQhz8M+KFxtHST+i0uxiTE55cLZOn/G7TqJ1mOGr+KvlJ9NgnLSsXv/T/mRo= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783695405; c=relaxed/simple; bh=95rDyyH8uLVV8MUfCUmqcc0G6oFkhuuh2+NqEXmebOM=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=ndd6HnCnF8+rtBD68uJvza9DKH1Vtea36AXYIWLtAHROENCrwv6e7ChgL/vcpegweWjBSLA3CVfnRKGfDqJuTON5wC856i3WzZnZ1FZfbFNhzrABmubsIPn7HDxGTLfMMIestaNeV3z4gAiQhjj0GQl1xYr4wqhqsxv+6NrBuFg= 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=WtG9+2WW; 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="WtG9+2WW" Received: from localhost (localhost [127.0.0.1]) by 011.lax.mailroute.net (Postfix) with ESMTP id 4gxZff6qcTz1XM5kW; Fri, 10 Jul 2026 14:56:42 +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=1783695393; x=1786287394; bh=k+M2661nw/s4/8gpr7YATI9W 2QztJaegEdr1VWFAcig=; b=WtG9+2WWuTWnl1hM8ijfcbogrIGQPobTLsJxKkYJ 4P86UqywYQyqXFK2bwWkAM9cWHanRVQVKpJ1AzQecBCQX2zMhqVYxysIfmLoVS/2 41kaysIpIZPY6Ur8+rXqbwnuA5pm9VAc+38RjTmky28/PhIP7OnwsFuZjSCHuJxT p8aGZPCyessyN2OafZZNOYh9cjODfsLFgx0pTBqDJwMd2RWkmGd0y1oBbovrkDu4 hs+tIxX6nCdkUzDqELXIm4xZYCPWeCC/9dA+2ruLA8p5NuGdPgMs+NnxZY4qIQYo 1KmccJxly0KKY/LbkJkAM0BOU4vjjqPnimXN/ZmdVpN76A== 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 HPIJqu_hWt31; Fri, 10 Jul 2026 14:56:33 +0000 (UTC) Received: from [192.168.50.14] (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 011.lax.mailroute.net (Postfix) with ESMTPSA id 4gxZfK2PMKz1XM5jn; Fri, 10 Jul 2026 14:56:24 +0000 (UTC) Message-ID: Date: Fri, 10 Jul 2026 07:56:23 -0700 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: [RFC] Significant Random I/O Performance Regression in Linux Kernel 6.18 (Up to 27.7%) Likely Caused by Commit 3c7ac40d7322 To: =?UTF-8?B?5a2Z6a2BIChLdWkgU3VuKQ==?= , Neil Armstrong , Alim Akhtar , Avri Altman , "James E.J. Bottomley" , "Martin K. Petersen" , "andre.draszik@linaro.org" Cc: Peter Griffin , Tudor Ambarus , Will McVicker , Manivannan Sadhasivam , "kernel-team@android.com" , "linux-samsung-soc@vger.kernel.org" , "linux-scsi@vger.kernel.org" , "linux-kernel@vger.kernel.org" , "stable@vger.kernel.org" , "linux-arm-msm@vger.kernel.org" , =?UTF-8?B?5byg5aaC5rOJIChSYWluIFpoYW5nKQ==?= , "cixi.geng@linux.dev" , =?UTF-8?B?5ZSQ5pyI5p6XIChZdWVsaW4gVGFuZyk=?= , =?UTF-8?B?6ZmI5paH6LaFIChXZW5jaGFvIENoZW4p?= , =?UTF-8?Q?Andr=C3=A9_Draszik?= References: <12a8417dc8644a71b9cb25c53c93805a@zeshmbx08.spreadtrum.com> Content-Language: en-US From: Bart Van Assche In-Reply-To: <12a8417dc8644a71b9cb25c53c93805a@zeshmbx08.spreadtrum.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable On 7/10/26 12:17 AM, =E5=AD=99=E9=AD=81 (Kui Sun) wrote: > Through investigation, we identified that upstream commit > 3c7ac40d732232fec0ba31d0a5e3cc9c112fc2e7, merged in April 2025, is > likely responsible for this performance drop. Two fixes for that commit are present in the upstream kernel. Are these fixes present in your kernel tree? commit eabcac808ca3ee9878223d4b49b750979029016b Author: Bart Van Assche Date: Fri Aug 15 08:58:23 2025 -0700 scsi: ufs: core: Fix IRQ lock inversion for the SCSI host lock commit 034d319c8899e8c5c0a35c6692c7fc7e8c12c374 Author: Nitin Rawat Date: Tue Jul 29 04:27:11 2025 +0530 scsi: ufs: core: Fix interrupt handling for MCQ Mode Thanks, Bart.