From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id F15F5C5DF63 for ; Wed, 6 Nov 2019 21:34:15 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id B28D4217D7 for ; Wed, 6 Nov 2019 21:34:15 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="M3VeFzKP"; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="TEzptdIS" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org B28D4217D7 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=CjFSCgybCBdjLzhLB0xdaGK4jpJqvqK21Fb20PbChO4=; b=M3VeFzKPL0LSPg oN0lfweTukrih3cV9a+6Qho+xkcyUv6bZBfNOI43CRrxTC/hNYU/K1rn3GVMc9ZSW3HRQwM/Fqd8H f4F1ylRhkzhbyDlVIrMrVlkK6Pz6Uau+h1uFaxW2I/XwdTFqw4S4XPmAFHj9URWhcY3PxtMjleZCC X+2cX1PSKV3q19Zphn6b8ovv3642KkJuPw1fCN77qXBsm+356PQO4qOBkv30mCEZlRAKzOSBrABL8 Iuousq1aKYKtu4XEoeqZHk62fX/MKFw/KVHYDiNu+Qs3iWzJKxgayw/drQ3GVUeW8rEHRawa2ytQq XfTwIwftUliXLQZpuNEQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1iSSwQ-000079-Bd; Wed, 06 Nov 2019 21:34:14 +0000 Received: from mail.kernel.org ([198.145.29.99]) by bombadil.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1iSSwN-00006e-FX for linux-nvme@lists.infradead.org; Wed, 06 Nov 2019 21:34:12 +0000 Received: from redsun51.ssa.fujisawa.hgst.com (unknown [199.255.47.7]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 895012166E; Wed, 6 Nov 2019 21:34:10 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1573076051; bh=SuV2UHwfH5+kWTYJPQHFsjavAYbiTOZxmHFjr4BmYbU=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=TEzptdIS/p4V2y7jFpj7BpoPbvy9qV6xz5NFSqk4ubIYojB59dstphSvEe1HLFhFL Ff+stGmFZJsyON+290/2nvCu+W6wbHOKRZ3kr2HUorOAKpdepcS1wJKMdm5xQYzbJT HV2GrxN94BtQnUDSZmz5XNf6PiwfXo/D6NpJZ0kI= Date: Thu, 7 Nov 2019 06:34:03 +0900 From: Keith Busch To: Eduard Hasenleithner Subject: Re: [RFC PATCH] Workaround for discard on non-conformant nvme devices Message-ID: <20191106213403.GA308@redsun51.ssa.fujisawa.hgst.com> References: <20191106182339.GE29853@redsun51.ssa.fujisawa.hgst.com> <20191106204329.GB32215@redsun51.ssa.fujisawa.hgst.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.12.1 (2019-06-15) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20191106_133411_539820_4D497249 X-CRM114-Status: GOOD ( 12.25 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Sagi Grimberg , linux-nvme@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Wed, Nov 06, 2019 at 10:10:58PM +0100, Eduard Hasenleithner wrote: > On 06.11.19 21:43, Keith Busch wrote: > > On Wed, Nov 06, 2019 at 09:22:00PM +0100, Eduard Hasenleithner wrote: > > > Couldn't we just simply use the discard_page for all discards? > > > > That's normally just a fallback to ensure forward progress under memory > > pressure. It's not particularly performant, though. > > So we are accepting a considerable performance impact for the "broken" > devices? I'd wager the devices that got this wrong are operating on DSMs beyond QD1 anyway, the impact to them is probably much less than "considerable". > > > Are there even nvme devices out there which have conformant behavior in this > > > respect? > > > > I believe most of them do conform, but I don't have a large sample size > > to confirm. > > Do you have an IO-MMU active on your setup? Sometimes, but that's not why I know at least some devices are compliant. I've wasted too many hours analyzing protocol traces. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme