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 42BAE1531EA for ; Wed, 13 Nov 2024 18:05:56 +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=1731521156; cv=none; b=YfN7ZWEyMDejWc03PojaTFygpU6skh80BXBgy17lhPhGVPizG+2IfrYFIWbB3EcOzPiRJHirRYHkSTRcf8jftvyRW7wvpkQmL/Pp8XaklBdpKaRFhhlCkhnBOokoAzC7PmFvkGC0YhwqT6qOVDGQjCMKtoahYFpTTVBSTeVBCDA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731521156; c=relaxed/simple; bh=M4wyj6LnteCS8V5uLYewkH2xB3uFMsAbftOFpnkE21o=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=jcQ6vqEBu6H49AkL4LOEBMHPFochk2LBvFPWlecoymyEJ7HscfLtjwShtR9YWuJgz/QZGuX/5l5kImHzQ+m5nLmQDYUlmZO0vrSwWkbbl32aKtrU91c6MVgFUu2OcuzO5Uy+J1nvFJtnBgmqOCjfx1snbAuQOdamNrLGSCJSI/Q= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=qmU33Ybq; 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="qmU33Ybq" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 49B17C4CEC3; Wed, 13 Nov 2024 18:05:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1731521155; bh=M4wyj6LnteCS8V5uLYewkH2xB3uFMsAbftOFpnkE21o=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=qmU33Ybq9mi6SS/EE9oMZnsYv/MW590U1NZ6DxaVzwGisRddMa9zzuYeFryV5QtDS QB1Jv6vnxMOSX5rBYRXUqOS6FowHhQT1bMVks5xuW99pozRML8wnXm4cFG85NjdzGN sSR7950AR4zd0WyLKTM/ulQ6dCiEyE19aEd+Fqdv8YjBgrrSbxG4SmYYkHVKZ+jLPL QrGdHEHKhxHtF1dkNEOcyR/ReyBh3o55WrDgYoW81e58yM1/+deuQylQTwfAfAIBql TRMEGUxOOiXKAwXkIx2XewWgBGCMPTERne0Kawf5CReHfULXbSqWrCv7oHRXgESeIY 4w6lf8eusXQeA== Date: Wed, 13 Nov 2024 11:05:53 -0700 From: Keith Busch To: Christoph Hellwig Cc: Bob Beckett , Jens Axboe , Sagi Grimberg , kernel@collabora.com, linux-nvme@lists.infradead.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] nvme-pci: 512 byte aligned dma pool segment quirk Message-ID: References: <20241112195053.3939762-1-bob.beckett@collabora.com> <20241113043151.GA20077@lst.de> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241113043151.GA20077@lst.de> On Wed, Nov 13, 2024 at 05:31:51AM +0100, Christoph Hellwig wrote: > On Tue, Nov 12, 2024 at 07:50:00PM +0000, Bob Beckett wrote: > > From: Robert Beckett > > > > We initially put in a quick fix of limiting the queue depth to 1 > > as experimentation showed that it fixed data corruption on 64GB > > steamdecks. > > > > After further experimentation, it appears that the corruption > > is fixed by aligning the small dma pool segments to 512 bytes. > > Testing via desync image verification shows that it now passes > > thousands of verification loops, where previously > > it never managed above 7. > > As suggested before, instead of changing the pool size please just > always use the large pool for this device. Well, he's doing what I suggested. I thought this was better because it puts the decision making in the initialization path instead of the IO path.