From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail-ej1-f46.google.com (mail-ej1-f46.google.com [209.85.218.46]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 09A12175570; Tue, 30 Apr 2024 13:31:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=209.85.218.46 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714483882; cv=none; b=LNbMPl+/NNTstr8Aqe2Wg5GmEn6xOe9b668l3tX2xADQmNbf72XPyB6ndkhT5j070lIW3o92pRV/l6mdtcxQ5xhm42gXvxYx7muZmQTFATacUw4W8KGWIxUQSAqlizqNk+0MucC3c5kEiTa6rv1kP5SXx/VdJH/DU1HIPxyPvGs= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1714483882; c=relaxed/simple; bh=SuC9FZBFdHxF1mZgxsS3cEgWTqlhBFUTnYsCDjyTNtU=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=NC00rlowCeXRadA/6XkeLdmWhGYisXKP7liXe1wRROjAXuFUoRG0vSSaslhyTlMZXKkjEd1kG3e8EuhFTr/3NDQ1c2q0YAedM8Y3B3YnVMfAv/to9n111W+88DEaJ6OCpW6Po32B+B0uzAipNrKpDiu0P5FAQ4k0Ld4P/1R0gcQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com; spf=pass smtp.mailfrom=gmail.com; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b=ZGDkLB6Z; arc=none smtp.client-ip=209.85.218.46 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=gmail.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="ZGDkLB6Z" Received: by mail-ej1-f46.google.com with SMTP id a640c23a62f3a-a556d22fa93so620037066b.3; Tue, 30 Apr 2024 06:31:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1714483879; x=1715088679; darn=vger.kernel.org; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :from:to:cc:subject:date:message-id:reply-to; bh=sQkyBn4Lnt15qpQKjjn6/FTdXdojZaggT0oJDgNx33c=; b=ZGDkLB6ZeQHM7S3Is+kCTnTiARqKq4qV587fbHYAro6WfXbhqOJl4xElhj+paZsYmf zsAUaz2PKpwWr/nReu83KrPWzL6GJ3NUIxxkikoY8QndVlFBB2kiW68I82oyP7jC6rRy Kue90XOs9J1KUp/gg2ntdEqvPa2dNn7gTu+YQBJukKO9o97AEgFgOwO/3/oDzmTNYn7Z y11S4Gq7YyhptxbmCSG4fqN/oKfSdHaJfTjR+/gghddtiAmMsnce6A9NKgDCIc8BdxRr 259AoX88DoDPU3UBi4BHE09WQIb1BCfB+Y6qiyc+rt/Pb6Hau/+OsPS5FrxyhRdjsoO+ KPYQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1714483879; x=1715088679; h=content-transfer-encoding:in-reply-to:from:content-language :references:cc:to:subject:user-agent:mime-version:date:message-id :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=sQkyBn4Lnt15qpQKjjn6/FTdXdojZaggT0oJDgNx33c=; b=JAcftVU9819Df72KVKUuHnMPN5upC2nEnDHOXmwiHa/Mqd+nmSAv3AMwHfJtBagS+e cT4dtJMHpeiKwD8GOBBfy7z9s+FlYWcf8y8O5DNvEbZ3jmEGdrqyeDORwHPNtJheMH8u wbr8sgNO5kk1/HagI63jfYfPZwnByelcETO0aRYQuUgULnKKWyrBVDRskUDNMqTI48+k Scnd785HFs5P9LWN4GE3HWvYb1Vr7EbjCdPGIYTLiprCO5P9LexLTNzWT1FY3dzcvFGe 8m82EnqztsJ+xRGTCSXLCXolzX7vhAll+CV5KiHaYTWPwu8g1HR9KqJcWBL0x3QmA995 /xXA== X-Forwarded-Encrypted: i=1; AJvYcCWO3Mh4iihGe+Ze3I9w69Mb8md/2Vgbcuk/pLV58IhsuuR2WJFdzyOfltYCYnTAzhyC3Q96pMnb/hapYki6ldbplKvipp/UGR14OMd7t+nyiHg9UAEhuQyqT390Cak0Dp389zqiVBmq8K56IZOWCR8LL7yrlDLr2eY7tghHxSHpoHbqi6gG11LFCEFiamASp3Vrj8sSNxwdF3/F5xLeXnqUhkRjJqFPXVMh4gGkdCMqR1e8LsIHJbmvUqAQjD+Plg/Xl64uBE2w1oL0lHwfzLclfEkOhylIGPpOYN0HOcP6L6hr4f568biULGqbqyAzHy+JxxkK/4RF2UQCccyO5l2TEBEKp0GpRMmu0l8RZU2Y/sDSbbOEDEI7+zWPY+EmYTeaBzOlsJQtRv9FwrepTHNgSLpUZDI/61aJJ5X7bi3PfaaLuxs5TehX6+ZnU5donnEdr74tYqEGIpcQNFOXqKitiOaOjKw1UyKmuRb9EQ== X-Gm-Message-State: AOJu0Yw6lPjiuEN734nsx/qsNMGgMZPKsd83Z7mLWp1YTakIoYgSLDHK 97DEipXt50d6B6REktqCeL5bFxAzsqNHolJf7BHCzaFFBuLw0vNj X-Google-Smtp-Source: AGHT+IG4D9H/56/A4rQ0pU5al3G+zQuIMq1mBSgq9KUwXS9Rk/+kL4o0ZAf4JvbTFbHU0G4DNFxL/g== X-Received: by 2002:a17:906:fb17:b0:a58:e74b:7e16 with SMTP id lz23-20020a170906fb1700b00a58e74b7e16mr2032608ejb.46.1714483879081; Tue, 30 Apr 2024 06:31:19 -0700 (PDT) Received: from [192.168.42.188] ([163.114.131.193]) by smtp.gmail.com with ESMTPSA id l9-20020a17090615c900b00a555be38aaasm15011385ejd.164.2024.04.30.06.31.16 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Tue, 30 Apr 2024 06:31:18 -0700 (PDT) Message-ID: <35a79edf-e4ca-4501-99ad-231a3ab2b216@gmail.com> Date: Tue, 30 Apr 2024 14:31:33 +0100 Precedence: bulk X-Mailing-List: linux-arch@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [RFC PATCH net-next v8 07/14] page_pool: devmem support To: Mina Almasry , David Wei Cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org, linux-doc@vger.kernel.org, linux-alpha@vger.kernel.org, linux-mips@vger.kernel.org, linux-parisc@vger.kernel.org, sparclinux@vger.kernel.org, linux-trace-kernel@vger.kernel.org, linux-arch@vger.kernel.org, bpf@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-media@vger.kernel.org, dri-devel@lists.freedesktop.org, "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Jonathan Corbet , Richard Henderson , Ivan Kokshaysky , Matt Turner , Thomas Bogendoerfer , "James E.J. Bottomley" , Helge Deller , Andreas Larsson , Jesper Dangaard Brouer , Ilias Apalodimas , Steven Rostedt , Masami Hiramatsu , Mathieu Desnoyers , Arnd Bergmann , Alexei Starovoitov , Daniel Borkmann , Andrii Nakryiko , Martin KaFai Lau , Eduard Zingerman , Song Liu , Yonghong Song , John Fastabend , KP Singh , Stanislav Fomichev , Hao Luo , Jiri Olsa , Steffen Klassert , Herbert Xu , David Ahern , Willem de Bruijn , Shuah Khan , Sumit Semwal , =?UTF-8?Q?Christian_K=C3=B6nig?= , Amritha Nambiar , Maciej Fijalkowski , Alexander Mikhalitsyn , Kaiyuan Zhang , Christian Brauner , Simon Horman , David Howells , Florian Westphal , Yunsheng Lin , Kuniyuki Iwashima , Jens Axboe , Arseniy Krasnov , Aleksander Lobakin , Michael Lass , Jiri Pirko , Sebastian Andrzej Siewior , Lorenzo Bianconi , Richard Gobert , Sridhar Samudrala , Xuan Zhuo , Johannes Berg , Abel Wu , Breno Leitao , Jason Gunthorpe , Shailend Chand , Harshitha Ramamurthy , Shakeel Butt , Jeroen de Borst , Praveen Kaligineedi , linux-mm@kvack.org, Matthew Wilcox References: <20240403002053.2376017-1-almasrymina@google.com> <20240403002053.2376017-8-almasrymina@google.com> <8357256a-f0e9-4640-8fec-23341fc607db@davidwei.uk> Content-Language: en-US From: Pavel Begunkov In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8bit On 4/27/24 03:11, Mina Almasry wrote: > On Fri, Apr 26, 2024 at 5:18 PM David Wei wrote: >> >> On 2024-04-02 5:20 pm, Mina Almasry wrote: >>> @@ -69,20 +106,26 @@ net_iov_binding(const struct net_iov *niov) >>> */ >>> typedef unsigned long __bitwise netmem_ref; >>> >>> +static inline bool netmem_is_net_iov(const netmem_ref netmem) >>> +{ >>> +#if defined(CONFIG_PAGE_POOL) && defined(CONFIG_DMA_SHARED_BUFFER) >> >> I am guessing you added this to try and speed up the fast path? It's >> overly restrictive for us since we do not need dmabuf necessarily. I >> spent a bit too much time wondering why things aren't working only to >> find this :( > > My apologies, I'll try to put the changelog somewhere prominent, or > notify you when I do something that I think breaks you. > > Yes, this is a by-product of a discussion with regards to the > page_pool benchmark regressions due to adding devmem. There is some > background on why this was added and the impact on the > bench_page_pool_simple tests in the cover letter. > > For you, I imagine you want to change this to something like: > > #if defined(CONFIG_PAGE_POOL) > #if defined(CONFIG_DMA_SHARED_BUFFER) || defined(CONFIG_IOURING) > > or something like that, right? Not sure if this is something I should Feels a bit flimsy, if the argument is that you want to be able to disable netmem overhead, then adding a netmem config option sounds like a better way forward. I have doubts this conditional handling is desirable in the first place, but perhaps I missed the discussion. > do here or if something more appropriate to be in the patches you > apply on top. > > I additionally think you may also need to run the > page_pool_benchmark_simple tests like I do in the cover letter to see > if you're affecting those. -- Pavel Begunkov