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=-13.3 required=3.0 tests=BAYES_00,DKIMWL_WL_MED, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_IN_DEF_DKIM_WL 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 4056DC433B4 for ; Thu, 20 May 2021 21:38:53 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 26D736138C for ; Thu, 20 May 2021 21:38:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230271AbhETVkN (ORCPT ); Thu, 20 May 2021 17:40:13 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40490 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230257AbhETVkL (ORCPT ); Thu, 20 May 2021 17:40:11 -0400 Received: from mail-lj1-x234.google.com (mail-lj1-x234.google.com [IPv6:2a00:1450:4864:20::234]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 48215C061574 for ; Thu, 20 May 2021 14:38:47 -0700 (PDT) Received: by mail-lj1-x234.google.com with SMTP id c15so21580839ljr.7 for ; Thu, 20 May 2021 14:38:47 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=20161025; h=mime-version:references:in-reply-to:from:date:message-id:subject:to :cc; bh=goseYwTkzgMm+FX+KCZopTYXh0tzEbkX4x36YfbUrsw=; b=EC5etK9i7fAPFZR2RrpV8bzGlnP0ytGmzkd7hkYjxPqb1E/JJAtuQXFeMofPFRcDHW TPq5jkxO+jZnj7CC1E/kNocAD+1S0fRowDF0LOnTYbhWVPj7S/wIHTf5MfZSrbMqb+8p 4qoW9Fdgfss9Ruo6qfzHavqNe3aOeNjWyvu97aGzHVeVaIETa/yJYwkx7Qfahm1KLOes NAUoGN1pybuE2UD7uuvQg6kQSxAUZ15V/0yAF8iqs/0ntH2olPZfBXvvzNhuPw8d4LD5 NWHpRb5OLMzCj8bb0YO1Wg8JXFcYByxSxl/kQDPA12IilD+EdlLjl9qL1m5nwLQEDAgJ 8gPA== 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=goseYwTkzgMm+FX+KCZopTYXh0tzEbkX4x36YfbUrsw=; b=qNW0ZFaBBLAJ1U4qyGOVl0UvwxS9NTenMb2WdyZ6Qo2Y6Hr9dJ+FNayVxD3k7nP9x1 8YwGdPUq43S6Wl7IgqGsRricAvTZfnnG3xsJz+7GfkH0xpDIOEhfHUlJldRWmd6er6vF YDNlQYT82bPjurntIe2++aMkJSz6udRzpfXF0BNRarTUqSZn4cW0gc1+H6wECVokAcrs xnu9SWatPjOEgQo24B/G4E0A3Zke7n+SV9m+15LgNcBOlhJpQctejdA6NnuzAcfWuqml XG9YqMRPwt3Vpdr2viqbiB3Bc1iTJH/i0LwT8oKsfmYI3axdTUeQWbC6PLGYLp8f4bTR Yv8g== X-Gm-Message-State: AOAM5335Zi8hUoBZVy+amST6+rQH+IJA/ZYYp60r0SPUwy2oP5I+1Jnh 0PS1flSXK47EPziO+JfSDBx6uUu7CsEN47FwZIv5Bw== X-Google-Smtp-Source: ABdhPJzwMrDBwob6pN+S2ilFdQh5N8EphMYiUtNUox7/axVceZ5jIphVm7b3994vHgkqA+TwbzuLpeYT6O39l9e/IaM= X-Received: by 2002:a2e:a54d:: with SMTP id e13mr2982312ljn.266.1621546725312; Thu, 20 May 2021 14:38:45 -0700 (PDT) MIME-Version: 1.0 References: <20210520183614.1227046-1-posk@google.com> <87mtspm7fe.fsf@meer.lwn.net> In-Reply-To: <87mtspm7fe.fsf@meer.lwn.net> From: Peter Oskolkov Date: Thu, 20 May 2021 14:38:33 -0700 Message-ID: Subject: Re: [RFC PATCH v0.1 0/9] UMCG early preview/RFC patchset To: Jonathan Corbet Cc: Peter Zijlstra , Ingo Molnar , Thomas Gleixner , Linux Kernel Mailing List , linux-api , Paul Turner , Ben Segall , Peter Oskolkov , Joel Fernandes , Andrew Morton , Andrei Vagin , Jim Newsome Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, May 20, 2021 at 2:17 PM Jonathan Corbet wrote: > > Peter Oskolkov writes: > > > As indicated earlier in the FUTEX_SWAP patchset: > > > > https://lore.kernel.org/lkml/20200722234538.166697-1-posk@posk.io/ > > > > "Google Fibers" is a userspace scheduling framework > > used widely and successfully at Google to improve in-process workload > > isolation and response latencies. We are working on open-sourcing > > this framework, and UMCG (User-Managed Concurrency Groups) kernel > > patches are intended as the foundation of this. > > So I have to ask...is there *any* documentation out there on what this > is and how people are supposed to use it? Shockingly, typing "Google > fibers" into Google leads to a less than fully joyful outcome... This > won't be easy for anybody to review if they have to start by > reverse-engineering what it's supposed to do. Hi Jonathan, There is this Linux Plumbers video: https://www.youtube.com/watch?v=KXuZi9aeGTw And the pdf: http://pdxplumbers.osuosl.org/2013/ocw//system/presentations/1653/original/LPC%20-%20User%20Threading.pdf I did not reference them in the patchset because links to sites other than kernel.org are strongly discouraged... I will definitely add a documentation patch. Feel free to reach out to me directly or through this LKML thread if you have any questions. Do you think a documentation patch would be useful at this point, as opposed to a free-form email discussion? Thanks, Peter > > Thanks, > > jon