From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out-177.mta0.migadu.com (out-177.mta0.migadu.com [91.218.175.177]) (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 BE11218A955 for ; Fri, 18 Oct 2024 07:26:56 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=91.218.175.177 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729236418; cv=none; b=kf+QprUnrJSzT4haHBQ4pzEsheHiV4Ivc+eQN1gtfl5XPNbAvDBcQx+SXXmOXfJ+8MCJEnvTptBeTDGfMcGhCcib7kInJCF1S08EBqJ/OsI4QxPNSJBxOAP9iRfzEKmj268abwdurRgYKDYJ3azmAPYDRFDJVm95fObOIM9VFR4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1729236418; c=relaxed/simple; bh=dJkcyFCfdw4XMhCX1tHVLniqjmkGISQAbTfuiB8fQxo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=PwwWmmSXTT85sM5Btw+FREWu+qS/2DwmIeXuXjobMjACIk3xwEDQMtWckBN4ttuFbIoXqXyPqcsPrC3ZAqKeDIZTGRTowsa05sbW3JZKrC5j0JRMDe3WjsRtK/IGfGIpgzMJqxlZApqXG3HbPEVlBc/1iQ29vn5MOoCEbBzCWY4= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev; spf=pass smtp.mailfrom=linux.dev; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b=fQLOosMG; arc=none smtp.client-ip=91.218.175.177 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.dev Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.dev Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.dev header.i=@linux.dev header.b="fQLOosMG" Message-ID: <5472cead-7965-47f5-9ee1-77d40062b897@linux.dev> DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.dev; s=key1; t=1729236414; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=/KFpx6VixP9yy4xxFaQWd//8YairifxkNNvdJP3idU4=; b=fQLOosMGk8sWYTwotPFATSnDYfULW8a0uCJnY30ZtcfNdCsMB5EATE3nlPA0a+C8iJY8es W/e5tK6eElVFajiqDZZAKZ4FmXKYVDdsRrCdUW8hdsfSZ3vuZ+Jo7n72a9QjCXEidgvLyI 3o9J+t3+AmK2JRJXLr9N8F6P5mgjlRw= Date: Fri, 18 Oct 2024 09:26:50 +0200 Precedence: bulk X-Mailing-List: linux-rdma@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Subject: Re: [PATCH v1 0/4] GPU Direct RDMA (P2P DMA) for Device Private Pages To: Yonatan Maman , Christoph Hellwig Cc: nouveau@lists.freedesktop.org, linux-kernel@vger.kernel.org, linux-rdma@vger.kernel.org, linux-mm@kvack.org, herbst@redhat.com, lyude@redhat.com, dakr@redhat.com, airlied@gmail.com, simona@ffwll.ch, jgg@ziepe.ca, leon@kernel.org, jglisse@redhat.com, akpm@linux-foundation.org, dri-devel@lists.freedesktop.org, apopple@nvidia.com, bskeggs@nvidia.com References: <20241015152348.3055360-1-ymaman@nvidia.com> <1a667504-72bd-445b-8bf8-a6604b7beb2b@nvidia.com> X-Report-Abuse: Please report any abuse attempt to abuse@migadu.com and include these headers. From: Zhu Yanjun In-Reply-To: <1a667504-72bd-445b-8bf8-a6604b7beb2b@nvidia.com> Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit X-Migadu-Flow: FLOW_OUT 在 2024/10/16 17:16, Yonatan Maman 写道: > > > On 16/10/2024 7:23, Christoph Hellwig wrote: >> On Tue, Oct 15, 2024 at 06:23:44PM +0300, Yonatan Maman wrote: >>> From: Yonatan Maman >>> >>> This patch series aims to enable Peer-to-Peer (P2P) DMA access in >>> GPU-centric applications that utilize RDMA and private device pages. >>> This >>> enhancement is crucial for minimizing data transfer overhead by allowing >>> the GPU to directly expose device private page data to devices such as >>> NICs, eliminating the need to traverse system RAM, which is the native >>> method for exposing device private page data. >> >> Please tone down your marketing language and explain your factual >> changes.  If you make performance claims back them by numbers. >> > > Got it, thanks! I'll fix that. Regarding performance, we’re achieving > over 10x higher bandwidth and 10x lower latency using perftest-rdma, > especially (with a high rate of GPU memory access). If I got this patch series correctly, this is based on ODP (On Demand Paging). And a way also exists which is based on non-ODP. From the following links, this way is implemented on efa, irdma and mlx5. 1. iRDMA https://lore.kernel.org/all/20230217011425.498847-1-yanjun.zhu@intel.com/ 2. efa https://lore.kernel.org/lkml/20211007114018.GD2688930@ziepe.ca/t/ 3. mlx5 https://lore.kernel.org/all/1608067636-98073-5-git-send-email-jianxin.xiong@intel.com/ Because these 2 methods are both implemented on mlx5, have you compared the test results with the 2 methods on mlx5? The most important results should be latency and bandwidth. Please let us know the test results. Thanks a lot. Zhu Yanjun