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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, 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 6B915C433ED for ; Fri, 7 May 2021 16:54:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 33B2561008 for ; Fri, 7 May 2021 16:54:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238436AbhEGQzT (ORCPT ); Fri, 7 May 2021 12:55:19 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60592 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238428AbhEGQzS (ORCPT ); Fri, 7 May 2021 12:55:18 -0400 Received: from mail-wr1-x429.google.com (mail-wr1-x429.google.com [IPv6:2a00:1450:4864:20::429]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 1494AC0613ED for ; Fri, 7 May 2021 09:54:17 -0700 (PDT) Received: by mail-wr1-x429.google.com with SMTP id m9so9962942wrx.3 for ; Fri, 07 May 2021 09:54:16 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=ffwll.ch; s=google; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=6IcOWYBUOtQoCBL1qPtrhl4ZlflWgXWFQU8YGjyhs7c=; b=NIKVq0m6gJjzBck2EAI1PVdmkAbsbaI4znOrznNtz8uXgXDzeBmuBeul21mUa8bFt4 uNJHE9B3ehF8bZeerXMHwqS6G21foVpmb3IQZtqRXhfYl9UnFQAikv/lXCxl6wTvLKd7 OmEDxdM0J1Vrfb4t9X/N6LOKM7wokQPZavKlk= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=6IcOWYBUOtQoCBL1qPtrhl4ZlflWgXWFQU8YGjyhs7c=; b=HMZfR7z1ec/UBzcNTSekq0BUtl5rYfUMmKuEMmYcNhF9rvV6nBfVVTCFD+ZiWB9IlM ASkF7kQlxsVQThMjTtRI8m/g8J8dca6bbjaaer8roSgwhysT9+QKtXrFU30l8onlx530 cJ6uPf49zdsbVw+qkEtycduMJWzjfHOZVz7ZFxuTjY5cXWG5DoLMJX2R2otNxvT7DVX9 GVVXc2dgc7Qo9Q2zz28hpFQRp0/8KUCxm0RADChMPtwiexWKRtQl8jCvnafDLVEdpJqo DlMFKWej8bFn59NK8yT5ch1JVEVcpimxXPZWFwkiTxTRKoeCCrh5rflz7L2rMYG5klLq ZHnA== X-Gm-Message-State: AOAM532k3P8nj+ycxqwc/fGYxNZz/Ukms8hbqwOBlAUhr8THpifyKwsL lb6qgiLPl/c19SgkLa0KiJYnkw== X-Google-Smtp-Source: ABdhPJx4XisqhypzoVmnN7f1cc81V9gCDgtdKMiD1+mhSs/hAB2Ds1VCFCcyfmp9AO96MGf2I/a4xg== X-Received: by 2002:a5d:6342:: with SMTP id b2mr13678480wrw.203.1620406455723; Fri, 07 May 2021 09:54:15 -0700 (PDT) Received: from phenom.ffwll.local ([2a02:168:57f4:0:efd0:b9e5:5ae6:c2fa]) by smtp.gmail.com with ESMTPSA id f4sm9632445wrz.33.2021.05.07.09.54.14 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 07 May 2021 09:54:15 -0700 (PDT) Date: Fri, 7 May 2021 18:54:13 +0200 From: Daniel Vetter To: Alex Deucher Cc: Daniel Vetter , Kenny Ho , Song Liu , Andrii Nakryiko , DRI Development , Daniel Borkmann , Kenny Ho , "open list:CONTROL GROUP (CGROUP)" , Brian Welty , John Fastabend , Alexei Starovoitov , amd-gfx list , Martin KaFai Lau , Linux-Fsdevel , Alexander Viro , Network Development , KP Singh , Yonghong Song , bpf , Dave Airlie , Alexei Starovoitov , Alex Deucher Subject: Re: [RFC] Add BPF_PROG_TYPE_CGROUP_IOCTL Message-ID: References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: X-Operating-System: Linux phenom 5.10.32scarlett+ Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Fri, May 07, 2021 at 12:50:07PM -0400, Alex Deucher wrote: > On Fri, May 7, 2021 at 12:31 PM Alex Deucher wrote: > > > > On Fri, May 7, 2021 at 12:26 PM Daniel Vetter wrote: > > > > > > On Fri, May 07, 2021 at 12:19:13PM -0400, Alex Deucher wrote: > > > > On Fri, May 7, 2021 at 12:13 PM Daniel Vetter wrote: > > > > > > > > > > On Fri, May 07, 2021 at 11:33:46AM -0400, Kenny Ho wrote: > > > > > > On Fri, May 7, 2021 at 4:59 AM Daniel Vetter wrote: > > > > > > > > > > > > > > Hm I missed that. I feel like time-sliced-of-a-whole gpu is the easier gpu > > > > > > > cgroups controler to get started, since it's much closer to other cgroups > > > > > > > that control bandwidth of some kind. Whether it's i/o bandwidth or compute > > > > > > > bandwidht is kinda a wash. > > > > > > sriov/time-sliced-of-a-whole gpu does not really need a cgroup > > > > > > interface since each slice appears as a stand alone device. This is > > > > > > already in production (not using cgroup) with users. The cgroup > > > > > > proposal has always been parallel to that in many sense: 1) spatial > > > > > > partitioning as an independent but equally valid use case as time > > > > > > sharing, 2) sub-device resource control as opposed to full device > > > > > > control motivated by the workload characterization paper. It was > > > > > > never about time vs space in terms of use cases but having new API for > > > > > > users to be able to do spatial subdevice partitioning. > > > > > > > > > > > > > CU mask feels a lot more like an isolation/guaranteed forward progress > > > > > > > kind of thing, and I suspect that's always going to be a lot more gpu hw > > > > > > > specific than anything we can reasonably put into a general cgroups > > > > > > > controller. > > > > > > The first half is correct but I disagree with the conclusion. The > > > > > > analogy I would use is multi-core CPU. The capability of individual > > > > > > CPU cores, core count and core arrangement may be hw specific but > > > > > > there are general interfaces to support selection of these cores. CU > > > > > > mask may be hw specific but spatial partitioning as an idea is not. > > > > > > Most gpu vendors have the concept of sub-device compute units (EU, SE, > > > > > > etc.); OpenCL has the concept of subdevice in the language. I don't > > > > > > see any obstacle for vendors to implement spatial partitioning just > > > > > > like many CPU vendors support the idea of multi-core. > > > > > > > > > > > > > Also for the time slice cgroups thing, can you pls give me pointers to > > > > > > > these old patches that had it, and how it's done? I very obviously missed > > > > > > > that part. > > > > > > I think you misunderstood what I wrote earlier. The original proposal > > > > > > was about spatial partitioning of subdevice resources not time sharing > > > > > > using cgroup (since time sharing is already supported elsewhere.) > > > > > > > > > > Well SRIOV time-sharing is for virtualization. cgroups is for > > > > > containerization, which is just virtualization but with less overhead and > > > > > more security bugs. > > > > > > > > > > More or less. > > > > > > > > > > So either I get things still wrong, or we'll get time-sharing for > > > > > virtualization, and partitioning of CU for containerization. That doesn't > > > > > make that much sense to me. > > > > > > > > You could still potentially do SR-IOV for containerization. You'd > > > > just pass one of the PCI VFs (virtual functions) to the container and > > > > you'd automatically get the time slice. I don't see why cgroups would > > > > be a factor there. > > > > > > Standard interface to manage that time-slicing. I guess for SRIOV it's all > > > vendor sauce (intel as guilty as anyone else from what I can see), but for > > > cgroups that feels like it's falling a bit short of what we should aim > > > for. > > > > > > But dunno, maybe I'm just dreaming too much :-) > > > > I don't disagree, I'm just not sure how it would apply to SR-IOV. > > Once you've created the virtual functions, you've already created the > > partitioning (regardless of whether it's spatial or temporal) so where > > would cgroups come into play? > > For some background, the SR-IOV virtual functions show up like actual > PCI endpoints on the bus, so SR-IOV is sort of like cgroups > implemented in hardware. When you enable SR-IOV, the endpoints that > are created are the partitions. Yeah I think we're massively agreeing right now :-) SRIOV is kinda by design vendor specific. You set up the VF endpoint, it shows up, it's all hw+fw magic. Nothing for cgroups to manage here at all. All I meant is that for the container/cgroups world starting out with time-sharing feels like the best fit, least because your SRIOV designers also seem to think that's the best first cut for cloud-y computing. Whether it's virtualized or containerized is a distinction that's getting ever more blurry, with virtualization become a lot more dynamic and container runtimes als possibly using hw virtualization underneath. -Daniel > > Alex > > > > > Alex > > > > > -Daniel > > > > > > > Alex > > > > > > > > > > > > > > Since time-sharing is the first thing that's done for virtualization I > > > > > think it's probably also the most reasonable to start with for containers. > > > > > -Daniel > > > > > -- > > > > > Daniel Vetter > > > > > Software Engineer, Intel Corporation > > > > > http://blog.ffwll.ch > > > > > _______________________________________________ > > > > > amd-gfx mailing list > > > > > amd-gfx@lists.freedesktop.org > > > > > https://lists.freedesktop.org/mailman/listinfo/amd-gfx > > > > > > -- > > > Daniel Vetter > > > Software Engineer, Intel Corporation > > > http://blog.ffwll.ch -- Daniel Vetter Software Engineer, Intel Corporation http://blog.ffwll.ch