From patchwork Mon Feb 5 11:04:22 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Alexander Lobakin X-Patchwork-Id: 13545257 X-Patchwork-Delegate: kuba@kernel.org Received: from mgamail.intel.com (mgamail.intel.com [192.198.163.7]) (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 33A241A5BA; Mon, 5 Feb 2024 11:05:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=192.198.163.7 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707131122; cv=none; b=D0ShCv9zCDsh8jIdjUAnEnbuC/p63X/N2nhsA1I6Op6vm5rgCFbbb+yJbXz9/Xm4BB/99sXvlxKPRKPqHho0E1CShcJ7nj6EPcpmAF309f7kdvHE6unP9umtARKNYbHIXeh/XuBZTnHk+TEa4VVjSrkJ0MdRYidqrKwtaTbdqPg= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1707131122; c=relaxed/simple; bh=LVf5BgWT9OSmbGH+Qwko5u5SJBVWf1jKCf7S7n+8WTs=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=tC3pSOWbc108x9GxKS5KzXIs6lxA75TqBhDd2cgPfUURonUcO7SrzMGGBggEY0PVLJAheqbn7oRm6pB6A4NwQzYdGa/y8y2Rup1jVwzAdTPhHUagwk+Zu1308HjZokAa4nIAifk7FWp+I/T9asvVFQ9gVP5vtpIAj7ZQNu+DiuM= 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=OFn7ejKn; arc=none smtp.client-ip=192.198.163.7 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="OFn7ejKn" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1707131120; x=1738667120; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=LVf5BgWT9OSmbGH+Qwko5u5SJBVWf1jKCf7S7n+8WTs=; b=OFn7ejKnfVsTz6m1MRO70tcOjMaFMF+XZPm/Zk6SoyjQV7gEyCq6xDo1 Isut9fXYTBYalKqIy6erni7Wjb8FHh7eKFdMaFhpa0zfYKuQ6TF+Y3qZu duG7l0vYo7YdjOmcle33LruJrkr1/mNISGmhNs7KA2U6xRtwavma3bOzu 1JsbTNMqlbyQU27obpMk8iymkKGhkEvnULjS8ZqjnYgD964kQT4pR8AZ6 T6iWi2mSZ37B+VOOXLV0hjy+maAHtOoow7QuywTLvTYItt9wI1BiqQX6h Ug9NA7tyuut7O6xGL+2WAb2nhDzh7iEMTxswhA+4LN9bptKnt6r+NNzMj w==; X-IronPort-AV: E=McAfee;i="6600,9927,10974"; a="25945326" X-IronPort-AV: E=Sophos;i="6.05,245,1701158400"; d="scan'208";a="25945326" Received: from fmviesa004.fm.intel.com ([10.60.135.144]) by fmvoesa101.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 05 Feb 2024 03:05:19 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.05,245,1701158400"; d="scan'208";a="5328048" Received: from newjersey.igk.intel.com ([10.102.20.203]) by fmviesa004.fm.intel.com with ESMTP; 05 Feb 2024 03:05:15 -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 v2 3/7] iommu/dma: avoid expensive indirect calls for sync operations Date: Mon, 5 Feb 2024 12:04:22 +0100 Message-ID: <20240205110426.764393-4-aleksander.lobakin@intel.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240205110426.764393-1-aleksander.lobakin@intel.com> References: <20240205110426.764393-1-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 --- 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,