From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from sender4-pp-f112.zoho.com (sender4-pp-f112.zoho.com [136.143.188.112]) (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 1260F1FAC3E for ; Wed, 13 Nov 2024 20:09:35 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=pass smtp.client-ip=136.143.188.112 ARC-Seal:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731528577; cv=pass; b=tqf8RNUn2QfFpd8iNxNn/yxHIkboBQHZYZ4pqb+0Ry/6eBUIHM/jUhz8q5MBcRmSaNjhtwM7vqUaAw8RbA3o1KgN79mYaKMkHIkjBwW9jw51VoFLUB+dRS0WJRaNNykkQxuWdKMCt8/SxtV6/aSUskKjcCnIlQVBvADC+9VyZBM= ARC-Message-Signature:i=2; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1731528577; c=relaxed/simple; bh=DLtVyS1Gle0W3YvZb1ONvyig+nqqFm1VbDN4+kU9mvM=; h=Date:From:To:Cc:Message-ID:In-Reply-To:References:Subject: MIME-Version:Content-Type; b=VWj0xfIdRszEjNXNDmuOE/d/XeySvInye/y1o2WFpoV8k8e68fTAkwleNetpVdmQ3tutcLcjkW/+V72N4FDiv6jl6TIRWo2jCuFW/O0utfV7FDjc4RLRH449Vk3VGm/dhRTjxsxfgszUpEAShOEjLuwReoZ8Z/X0R6Ho/yrpbpo= ARC-Authentication-Results:i=2; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com; spf=pass smtp.mailfrom=collabora.com; dkim=pass (1024-bit key) header.d=collabora.com header.i=bob.beckett@collabora.com header.b=HL9WTd8/; arc=pass smtp.client-ip=136.143.188.112 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=collabora.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=collabora.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=collabora.com header.i=bob.beckett@collabora.com header.b="HL9WTd8/" ARC-Seal: i=1; a=rsa-sha256; t=1731528559; cv=none; d=zohomail.com; s=zohoarc; b=ZFzX5aS+y1VRNZ7MaWQQQyDPBqnPt7/jrgPProgeKZ6Zl2VespVImQD2sq9WDv7hrxdPPBiR+B+T2MIws1qRd9DQRC/rwiNkIqktyXwJvw4YvwRNOoqY0oo113lGJ/QrfbmvYlWsdE9R1VuDn4lrD/nuUjkmpT8U/+Y62Wdida4= ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=zohomail.com; s=zohoarc; t=1731528559; h=Content-Type:Content-Transfer-Encoding:Cc:Cc:Date:Date:From:From:In-Reply-To:MIME-Version:Message-ID:References:Subject:Subject:To:To:Message-Id:Reply-To; bh=dguBOGoGelrYVmBNPYN9y9wYEeTWSEzdw6LC5L93zYc=; b=JwcEuR6zKWXyi8xQBJX0DJl9HBu6W04HSEEQm3cmmnF2wB+ANocSQRB5NOUAowjFBiwgoSlGrLDA5xknwm7GCqFY9P4JTiKy1w/gFvDHBBzltAy+7xbtTiZQsvGIivfNvzzbvQaHMsJ0zzsHp10o4sEhcP8v1Hs6Nt32IbhNUjk= ARC-Authentication-Results: i=1; mx.zohomail.com; dkim=pass header.i=collabora.com; spf=pass smtp.mailfrom=bob.beckett@collabora.com; dmarc=pass header.from= DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; t=1731528559; s=zohomail; d=collabora.com; i=bob.beckett@collabora.com; h=Date:Date:From:From:To:To:Cc:Cc:Message-ID:In-Reply-To:References:Subject:Subject:MIME-Version:Content-Type:Content-Transfer-Encoding:Message-Id:Reply-To; bh=dguBOGoGelrYVmBNPYN9y9wYEeTWSEzdw6LC5L93zYc=; b=HL9WTd8/38/qjcGLHF57Lh1gXYxUV5k3u27JC5CI0Zt31pKIWok2LoyEbDpXJg8C ptG6eUZvxrJR9lIa3mNZGjg1ku1F4azXtvIhBPxeX/Yg5wSp5IPMqsfubLGWRaAeufl WamOmKSFLYR1YyKirHd4RIeM83Q2Y10IQ6sGjojk= Received: from mail.zoho.com by mx.zohomail.com with SMTP id 1731528528260910.1748320725312; Wed, 13 Nov 2024 12:08:48 -0800 (PST) Date: Wed, 13 Nov 2024 20:08:48 +0000 From: Robert Beckett To: "Keith Busch" Cc: "Christoph Hellwig" , "Jens Axboe" , "Sagi Grimberg" , "kernel" , "linux-nvme" , "linux-kernel" Message-ID: <19327249129.1131b0ddd320896.1106904208694557670@collabora.com> In-Reply-To: References: <20241112195053.3939762-1-bob.beckett@collabora.com> <20241113043151.GA20077@lst.de> Subject: Re: [PATCH] nvme-pci: 512 byte aligned dma pool segment quirk 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="UTF-8" Content-Transfer-Encoding: 7bit Importance: Medium User-Agent: Zoho Mail X-Mailer: Zoho Mail ---- On Wed, 13 Nov 2024 18:05:53 +0000 Keith Busch wrote --- > 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 bob.beckett@collabora.com> > > > > > > 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. > yep, this avoids any extra conditional in the fast path