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=-4.5 required=3.0 tests=DKIM_ADSP_CUSTOM_MED, DKIM_INVALID,DKIM_SIGNED,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,HK_RANDOM_FROM,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 A3CACC76195 for ; Fri, 19 Jul 2019 04:26:13 +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 785522173B for ; Fri, 19 Jul 2019 04:26:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ZglmsGRh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 785522173B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com 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 30CF921A4; Fri, 19 Jul 2019 04:26:13 +0000 (UTC) Received: from smtp1.linuxfoundation.org (smtp1.linux-foundation.org [172.17.192.35]) by mail.linuxfoundation.org (Postfix) with ESMTPS id A5DEC21A0 for ; Fri, 19 Jul 2019 04:25:52 +0000 (UTC) X-Greylist: whitelisted by SQLgrey-1.7.6 Received: from mail-io1-f66.google.com (mail-io1-f66.google.com [209.85.166.66]) by smtp1.linuxfoundation.org (Postfix) with ESMTPS id 98D07F8 for ; Fri, 19 Jul 2019 04:25:51 +0000 (UTC) Received: by mail-io1-f66.google.com with SMTP id q22so55704204iog.4 for ; Thu, 18 Jul 2019 21:25:51 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=aEV/B/zfslSF4whrA8qZ2mb0nmcoO++IurBGcD9Yv4U=; b=ZglmsGRhAS8Qtc8o9xBVl/7WJ+NHL+DvG3giBl6HGmblKAtysO3VzRG3nVmNEzGZwN 3puZVBa5jjVrWhAkLK/xhgdH8R6KP86XrMPkjKl+zDLx61MQfwRVKF0Nq7ZggSXjyv9V 9BVFlpPiwaZR1nY8ow+lU/bSxyvOpOmkJSPIpqZ70LuJ0dDaHKtGJqgWwWFxmzUxEaQs 2OKCE5ghX1VWbwwbDJckSv5561HV2bPDmAER3Z9VW2wBW6x/8gGh/jnkTuDqnAziVt0L 1cFdqK5VqHwd32edUd/gDv9DlVLn+Zk/L6wSw9baMZlXT53haMkn8RK78ALbwOkv8T/M OC7Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=aEV/B/zfslSF4whrA8qZ2mb0nmcoO++IurBGcD9Yv4U=; b=UYAnRWuYLwjywBvhVg8PY9f2kZQ0w5pLzJmOrMXzI4SAo7iE1HRGvMpjzcv82b26HU ektvL9mTWq03OhhTZ8VemU46lUkjZn0xP6lATLxYAyLOEjGNJ9aCqjBDzywWqn/1lV9t Sq5ERng5E1P0WhYZRrG0o5/z/kLHugX978rqqOgdkP51TgEVZxDp+S3xV9uSuV2e1cnh mlTQYWUFr1RQLnGFBnEXcFcp2xlzT7VtSdbpV7E0YAZUmv8FSyUDr52EOGuasJVQNQBq SDvf5QG3HnP+oA+RZnxrfXcW8fQ5nJmErb37IdnbkntjtcTDZvOKQkxL5OhhbkG7DqpO gW5g== X-Gm-Message-State: APjAAAXIfhP3d/uKo73mM+xUTl7Vat3xD3xVf8MxFDbwIQj69Rl+WJdH pAB1yZD/W5/FOpatAz0bLuOWscvMcHg/6NMYqjw= X-Google-Smtp-Source: APXvYqz0l7cKVZZSjWpBAW6HMScMdZEAkzvtTOzb71tNuSDpsv+lK/DSvININq0epUP4KkCslzsarBELEJizVKGb1cY= X-Received: by 2002:a02:b713:: with SMTP id g19mr52932372jam.77.1563510350938; Thu, 18 Jul 2019 21:25:50 -0700 (PDT) MIME-Version: 1.0 References: <20190711171927.28803-1-will@kernel.org> In-Reply-To: <20190711171927.28803-1-will@kernel.org> From: Ganapatrao Kulkarni Date: Fri, 19 Jul 2019 09:55:39 +0530 Message-ID: Subject: Re: [RFC PATCH v2 00/19] Try to reduce lock contention on the SMMUv3 command queue To: Will Deacon Cc: Vijay Kilary , Jean-Philippe Brucker , Jon Masters , Jan Glauber , Alex Williamson , iommu@lists.linux-foundation.org, Jayachandran Chandrasekharan Nair , 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 Hi Will, On Thu, Jul 11, 2019 at 10:58 PM Will Deacon wrote: > > Hi everyone, > > This is a significant rework of the RFC I previously posted here: > > https://lkml.kernel.org/r/20190611134603.4253-1-will.deacon@arm.com > > But this time, it looks like it might actually be worthwhile according > to my perf profiles, where __iommu_unmap() falls a long way down the > profile for a multi-threaded netperf run. I'm still relying on others to > confirm this is useful, however. > > Some of the changes since last time are: > > * Support for constructing and submitting a list of commands in the > driver > > * Numerous changes to the IOMMU and io-pgtable APIs so that we can > submit commands in batches > > * Removal of cmpxchg() from cmdq_shared_lock() fast-path > > * Code restructuring and cleanups > > This current applies against my iommu/devel branch that Joerg has pulled > for 5.3. If you want to test it out, I've put everything here: > > https://git.kernel.org/pub/scm/linux/kernel/git/will/linux.git/log/?h=iommu/cmdq > > Feedback welcome. I appreciate that we're in the merge window, but I > wanted to get this on the list for people to look at as an RFC. I have tried branch iommu/cmdq on ThunderX2. I do see there is drastic reduction in CPU bandwidth consumption(from 15 to 20% to 1 to 2% in perf top) from SMMU CMDQ helper functions, when I run iperf with more than 64 clients(-P 64). However I have not noticed any measurable performance improvement in iperf results. IMO, this might/should help in performance improvement of IO intensive workloads. FWIW, you can add, Tested-by: Ganapatrao Kulkarni > > Cheers, > > Will > > --->8 > > Cc: Jean-Philippe Brucker > Cc: Robin Murphy > Cc: Jayachandran Chandrasekharan Nair > Cc: Jan Glauber > Cc: Jon Masters > Cc: Eric Auger > Cc: Zhen Lei > Cc: Jonathan Cameron > Cc: Vijay Kilary > Cc: Joerg Roedel > Cc: John Garry > Cc: Alex Williamson > > Will Deacon (19): > iommu: Remove empty iommu_tlb_range_add() callback from iommu_ops > iommu/io-pgtable-arm: Remove redundant call to io_pgtable_tlb_sync() > iommu/io-pgtable: Rename iommu_gather_ops to iommu_flush_ops > iommu: Introduce struct iommu_iotlb_gather for batching TLB flushes > iommu: Introduce iommu_iotlb_gather_add_page() > iommu: Pass struct iommu_iotlb_gather to ->unmap() and ->iotlb_sync() > iommu/io-pgtable: Introduce tlb_flush_walk() and tlb_flush_leaf() > iommu/io-pgtable: Hook up ->tlb_flush_walk() and ->tlb_flush_leaf() in > drivers > iommu/io-pgtable-arm: Call ->tlb_flush_walk() and ->tlb_flush_leaf() > iommu/io-pgtable: Replace ->tlb_add_flush() with ->tlb_add_page() > iommu/io-pgtable: Remove unused ->tlb_sync() callback > iommu/io-pgtable: Pass struct iommu_iotlb_gather to ->unmap() > iommu/io-pgtable: Pass struct iommu_iotlb_gather to ->tlb_add_page() > iommu/arm-smmu-v3: Separate s/w and h/w views of prod and cons indexes > iommu/arm-smmu-v3: Drop unused 'q' argument from Q_OVF macro > iommu/arm-smmu-v3: Move low-level queue fields out of arm_smmu_queue > iommu/arm-smmu-v3: Operate directly on low-level queue where possible > iommu/arm-smmu-v3: Reduce contention during command-queue insertion > iommu/arm-smmu-v3: Defer TLB invalidation until ->iotlb_sync() > > drivers/gpu/drm/panfrost/panfrost_mmu.c | 24 +- > drivers/iommu/amd_iommu.c | 11 +- > drivers/iommu/arm-smmu-v3.c | 856 ++++++++++++++++++++++++-------- > drivers/iommu/arm-smmu.c | 103 +++- > drivers/iommu/dma-iommu.c | 9 +- > drivers/iommu/exynos-iommu.c | 3 +- > drivers/iommu/intel-iommu.c | 3 +- > drivers/iommu/io-pgtable-arm-v7s.c | 57 +-- > drivers/iommu/io-pgtable-arm.c | 48 +- > drivers/iommu/iommu.c | 24 +- > drivers/iommu/ipmmu-vmsa.c | 28 +- > drivers/iommu/msm_iommu.c | 42 +- > drivers/iommu/mtk_iommu.c | 45 +- > drivers/iommu/mtk_iommu_v1.c | 3 +- > drivers/iommu/omap-iommu.c | 2 +- > drivers/iommu/qcom_iommu.c | 44 +- > drivers/iommu/rockchip-iommu.c | 2 +- > drivers/iommu/s390-iommu.c | 3 +- > drivers/iommu/tegra-gart.c | 12 +- > drivers/iommu/tegra-smmu.c | 2 +- > drivers/vfio/vfio_iommu_type1.c | 27 +- > include/linux/io-pgtable.h | 57 ++- > include/linux/iommu.h | 92 +++- > 23 files changed, 1090 insertions(+), 407 deletions(-) > > -- > 2.11.0 > Thanks, Ganapat > _______________________________________________ > iommu mailing list > iommu@lists.linux-foundation.org > https://lists.linuxfoundation.org/mailman/listinfo/iommu _______________________________________________ iommu mailing list iommu@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/iommu