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=-7.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED, USER_AGENT_SANE_1 autolearn=ham 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 B2077C3A589 for ; Thu, 15 Aug 2019 13:55:36 +0000 (UTC) Received: from mail.linuxfoundation.org (mail.linuxfoundation.org [140.211.169.12]) (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 853A6208C2 for ; Thu, 15 Aug 2019 13:55:36 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="ZSXhKCXn" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 853A6208C2 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=iommu-bounces@lists.linux-foundation.org Received: from mail.linux-foundation.org (localhost [127.0.0.1]) by mail.linuxfoundation.org (Postfix) with ESMTP id 5A9D3EEB; Thu, 15 Aug 2019 13:55:36 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id 3950FEE4 for ; Thu, 15 Aug 2019 13:55:35 +0000 (UTC) Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id E062787B for ; Thu, 15 Aug 2019 13:55:34 +0000 (UTC) Received: from willie-the-truck (236.31.169.217.in-addr.arpa [217.169.31.236]) (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 5A0942086C; Thu, 15 Aug 2019 13:55:32 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1565877334; bh=5wfdAeZ3utUPYQaQDWs/sPCscNo9VPDGdHObDpJgZkA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=ZSXhKCXnjT2MHojqRaEFTPxafHmaj9lMMhHJUpp43bu0tOq3kPe9BYmQjtTmS1cxI yPAmnhyd3tcv2gKM9FioP06CRf/UfBdxlgJ1p2oVvCNaXLzfQ2B80Dzj9FVNxlt5E9 WDQZVtHduPewVZJ9mtJQZLV08NiopSr1aD8Z7/fs= Date: Thu, 15 Aug 2019 14:55:29 +0100 From: Will Deacon To: John Garry Subject: Re: [PATCH 00/13] Rework IOMMU API to allow for batching of invalidation Message-ID: <20190815135528.d7ip6dkqdwwvjy64@willie-the-truck> References: <20190814175634.21081-1-will@kernel.org> <78d366b7-590f-b114-1a9a-91dea01cde4d@huawei.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <78d366b7-590f-b114-1a9a-91dea01cde4d@huawei.com> User-Agent: NeoMutt/20170113 (1.7.2) Cc: Jean-Philippe Brucker , Vijay Kilary , Jon Masters , Jan Glauber , Alex Williamson , iommu@lists.linux-foundation.org, Jayachandran Chandrasekharan Nair , David Woodhouse , Robin Murphy X-BeenThere: iommu@lists.linux-foundation.org X-Mailman-Version: 2.1.12 Precedence: list List-Id: Development issues for Linux IOMMU support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: iommu-bounces@lists.linux-foundation.org Errors-To: iommu-bounces@lists.linux-foundation.org On Thu, Aug 15, 2019 at 12:19:58PM +0100, John Garry wrote: > On 14/08/2019 18:56, Will Deacon wrote: > > If you'd like to play with the patches, then I've also pushed them here: > > > > https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/log/?h=iommu/unmap > > > > but they should behave as a no-op on their own. > > As anticipated, my storage testing scenarios roughly give parity throughput > and CPU loading before and after this series. > > Patches to convert the > > Arm SMMUv3 driver to the new API are here: > > > > https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/log/?h=iommu/cmdq > > I quickly tested this again and now I see a performance lift: > > before (5.3-rc1) after > D05 8x SAS disks 907K IOPS 970K IOPS > D05 1x NVMe 450K IOPS 466K IOPS > D06 1x NVMe 467K IOPS 466K IOPS > > The CPU loading seems to track throughput, so nothing much to say there. > > Note: From 5.2 testing, I was seeing >900K IOPS from that NVMe disk for > !IOMMU. Cheers, John. For interest, how do things look if you pass iommu.strict=0? That might give some indication about how much the invalidation is still hurting us. > BTW, what were your thoughts on changing > arm_smmu_atc_inv_domain()->arm_smmu_atc_inv_master() to batching? It seems > suitable, but looks untouched. Were you waiting for a resolution to the > performance issue which Leizhen reported? In principle, I'm supportive of such a change, but I'm not currently able to test any ATS stuff so somebody else would need to write the patch. Jean-Philippe is on holiday at the moment, but I'd be happy to review something from you if you send it out. Will _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu