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=-2.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, 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 4F360C43462 for ; Fri, 7 May 2021 16:50:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2532461463 for ; Fri, 7 May 2021 16:50:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238412AbhEGQvU (ORCPT ); Fri, 7 May 2021 12:51:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59716 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233797AbhEGQvT (ORCPT ); Fri, 7 May 2021 12:51:19 -0400 Received: from mail-oo1-xc2f.google.com (mail-oo1-xc2f.google.com [IPv6:2607:f8b0:4864:20::c2f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 08849C061574; Fri, 7 May 2021 09:50:19 -0700 (PDT) Received: by mail-oo1-xc2f.google.com with SMTP id s1-20020a4ac1010000b02901cfd9170ce2so2097410oop.12; Fri, 07 May 2021 09:50:19 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=gEhp98aWgf02GTF44Vv5XNSpyCZQUaDhXZ1T/jvvLtA=; b=JORdvGomBxcOgeh8Aw+kCftF8w4jJ6wKk61sca7YG6GZTd87uNKFNfzGesgagdq079 jmIHJRTDP/ZydemJfTZ6mJE3qOJXukS3jDrh6ZfpR4qdE+tlOPXBHpK6HbSv1yrjMDDc 5A05p1WTniQcRC6hlqCUOHFTjjTtf+Rekwb3Xk9Ar3ellN+/4E1Ip1ZJc8JzgkE55HJd uABpNTFzNCvzbG2ywN2Y1AscaOmzb5athRt7SrP3oaonCaeMMjNUNGhoeEZ2bHRqmGvd KzOsBW3EREVB4wwYHIzns+48YOleRgWLS2I4ZVDKf1he2a+G9G54B4DRmiElMH/g6/EO gN8Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=gEhp98aWgf02GTF44Vv5XNSpyCZQUaDhXZ1T/jvvLtA=; b=RCxcUBtQEt8D1bu56bIeLuc01nHxlgNgQijyeZUy00poI31vcBCN/NVtxUVKqXwQKE TZTTOjq2GZUsvcrCg/6hohHDFfX/r6r8zIFImpqBdOF6EjQOi0iHei5fwboFhSAAjkp6 nzp73WCvKxVMe2SoG3rvxScAIj0L1IweBDF8HXh2jEIDrMYG8+3n2mGysNVE7obpSmUy GGMQdu8m/lLZnLAgyAWQhGn3JBEDOJBFUTeRgSkxKCG7legW0PIm/FpVwDQSYHRFVNlK YfHUt2vAiAd8+UTebIpaiQihEj+moaNiVqE1DHTtROFbMxtJLoAVIxmzEzEcux8kcxBk kkIA== X-Gm-Message-State: AOAM5312OfZEYZXtwACTDxMFzuPAWNs2Zq3dCByEZsm6vd+1ya+w0ZDI 3lunCp/TNUzWAwFwulb26xngRAPYGU5m/r9TKxg= X-Google-Smtp-Source: ABdhPJwhHBPINVIrJEa2Eetgoqm/GYzk8Jzl1rM/fYedkREtS21pQlINfBkfNOiB31jt2P6jFp4QeTclpwPFqehsvPE= X-Received: by 2002:a4a:d004:: with SMTP id h4mr8418227oor.90.1620406218393; Fri, 07 May 2021 09:50:18 -0700 (PDT) MIME-Version: 1.0 References: In-Reply-To: From: Alex Deucher Date: Fri, 7 May 2021 12:50:07 -0400 Message-ID: Subject: Re: [RFC] Add BPF_PROG_TYPE_CGROUP_IOCTL To: Daniel Vetter Cc: 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 Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org 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. 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