From patchwork Wed Feb 14 16:21:57 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Lobakin X-Patchwork-Id: 13556726 X-Patchwork-Delegate: kuba@kernel.org Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.12]) (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 9B02060DE2; Wed, 14 Feb 2024 16:22:54 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.12 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707927776; cv=none; b=GUF7SGDak/LU/bzMD+eNKQbrfaJYwNATPoGM++kbZnMtw3ASLP3ivd+rCKk4oHyiPFo0rlAGaL+l7Uh64blyOvwEINb2BuCdUUXM5al+Zw4HYrZZROcLqP+Anf5vE4062F/KBoLGpqRSys0W0KR30F9ZT1I+uZ7CAs81Kj3x+gw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707927776; c=relaxed/simple; bh=LVf5BgWT9OSmbGH+Qwko5u5SJBVWf1jKCf7S7n+8WTs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=cr8JNv9ggdVKV2zUaXJAn2ZOTqdpbQtJpKPIdmTuMq87EM8A2RCzNwxq4DVtKReDZzN+MCWSnTYrWIuNTD3iFhpsQTM/7BQ7M9oBsE9SbbOfK/ch4Qa3bIG5tmiFuN/hBk37iDk3lsIijl7BIXWBPnEEuzOMzHXjIJNiSdNlk3A= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=XZCI7xAs; arc=none smtp.client-ip=192.198.163.12 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="XZCI7xAs" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1707927774; x=1739463774; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=LVf5BgWT9OSmbGH+Qwko5u5SJBVWf1jKCf7S7n+8WTs=; b=XZCI7xAseoMQmku7hs3afH1TFpoM5LdApzAmTc9FxyvFOvpVfcVFlySy fA7YruRI1xUBsp0VjL8TKuIQM0Ugv2jElBxsc3ZcpsOcGvPpml76qLiaF ResO5SLLX2Lwp9ml0w4oddszgZEqI72oy6VGdFHgnfjti/3hitP4C2Pqj WIwLVTJrrUvrIno3L9+AGhdJWYy08N3DUgzE7LJ5zdCohBxjqoOn3/XV2 pLzLrNguAv/ND9DnPPoX0D9Do9I7d9BEppJpZ8RBWHm+m/LHyBEl8c5jF JQ/EKpsRL/hayVc+P/foNiGzaR3nJTWxYSoe69r0mYgzVF1m1EPVg5Sof A==; X-IronPort-AV: E=McAfee;i="6600,9927,10984"; a="5755570" X-IronPort-AV: E=Sophos;i="6.06,159,1705392000"; d="scan'208";a="5755570" Received: from fmviesa002.fm.intel.com ([10.60.135.142]) by fmvoesa106.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Feb 2024 08:22:54 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.06,159,1705392000"; d="scan'208";a="26400001" Received: from newjersey.igk.intel.com ([10.102.20.203]) by fmviesa002.fm.intel.com with ESMTP; 14 Feb 2024 08:22:50 -0800 From: Alexander Lobakin To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni Cc: Alexander Lobakin , Christoph Hellwig , Marek Szyprowski , Robin Murphy , Joerg Roedel , Will Deacon , Greg Kroah-Hartman , "Rafael J. Wysocki" , Magnus Karlsson , Maciej Fijalkowski , Alexander Duyck , bpf@vger.kernel.org, netdev@vger.kernel.org, iommu@lists.linux.dev, linux-kernel@vger.kernel.org Subject: [PATCH net-next v3 3/7] iommu/dma: avoid expensive indirect calls for sync operations Date: Wed, 14 Feb 2024 17:21:57 +0100 Message-ID: <20240214162201.4168778-4-aleksander.lobakin@intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240214162201.4168778-1-aleksander.lobakin@intel.com> References: <20240214162201.4168778-1-aleksander.lobakin@intel.com> Precedence: bulk X-Mailing-List: bpf@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Patchwork-Delegate: kuba@kernel.org When IOMMU is on, the actual synchronization happens in the same cases as with the direct DMA. Advertise %DMA_F_CAN_SKIP_SYNC in IOMMU DMA to skip sync ops calls (indirect) for non-SWIOTLB buffers. perf profile before the patch: 18.53% [kernel] [k] gq_rx_skb 14.77% [kernel] [k] napi_reuse_skb 8.95% [kernel] [k] skb_release_data 5.42% [kernel] [k] dev_gro_receive 5.37% [kernel] [k] memcpy <*> 5.26% [kernel] [k] iommu_dma_sync_sg_for_cpu 4.78% [kernel] [k] tcp_gro_receive <*> 4.42% [kernel] [k] iommu_dma_sync_sg_for_device 4.12% [kernel] [k] ipv6_gro_receive 3.65% [kernel] [k] gq_pool_get 3.25% [kernel] [k] skb_gro_receive 2.07% [kernel] [k] napi_gro_frags 1.98% [kernel] [k] tcp6_gro_receive 1.27% [kernel] [k] gq_rx_prep_buffers 1.18% [kernel] [k] gq_rx_napi_handler 0.99% [kernel] [k] csum_partial 0.74% [kernel] [k] csum_ipv6_magic 0.72% [kernel] [k] free_pcp_prepare 0.60% [kernel] [k] __napi_poll 0.58% [kernel] [k] net_rx_action 0.56% [kernel] [k] read_tsc <*> 0.50% [kernel] [k] __x86_indirect_thunk_r11 0.45% [kernel] [k] memset After patch, lines with <*> no longer show up, and overall cpu usage looks much better (~60% instead of ~72%): 25.56% [kernel] [k] gq_rx_skb 9.90% [kernel] [k] napi_reuse_skb 7.39% [kernel] [k] dev_gro_receive 6.78% [kernel] [k] memcpy 6.53% [kernel] [k] skb_release_data 6.39% [kernel] [k] tcp_gro_receive 5.71% [kernel] [k] ipv6_gro_receive 4.35% [kernel] [k] napi_gro_frags 4.34% [kernel] [k] skb_gro_receive 3.50% [kernel] [k] gq_pool_get 3.08% [kernel] [k] gq_rx_napi_handler 2.35% [kernel] [k] tcp6_gro_receive 2.06% [kernel] [k] gq_rx_prep_buffers 1.32% [kernel] [k] csum_partial 0.93% [kernel] [k] csum_ipv6_magic 0.65% [kernel] [k] net_rx_action iavf yields +10% of Mpps on Rx. This also unblocks batched allocations of XSk buffers when IOMMU is active. Co-developed-by: Eric Dumazet Signed-off-by: Eric Dumazet Signed-off-by: Alexander Lobakin Acked-by: Robin Murphy --- drivers/iommu/dma-iommu.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/drivers/iommu/dma-iommu.c b/drivers/iommu/dma-iommu.c index 50ccc4f1ef81..4ab9ac13d362 100644 --- a/drivers/iommu/dma-iommu.c +++ b/drivers/iommu/dma-iommu.c @@ -1707,7 +1707,8 @@ static size_t iommu_dma_opt_mapping_size(void) } static const struct dma_map_ops iommu_dma_ops = { - .flags = DMA_F_PCI_P2PDMA_SUPPORTED, + .flags = DMA_F_PCI_P2PDMA_SUPPORTED | + DMA_F_CAN_SKIP_SYNC, .alloc = iommu_dma_alloc, .free = iommu_dma_free, .alloc_pages = dma_common_alloc_pages,