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=-2.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 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 97692C433FF for ; Thu, 1 Aug 2019 21:59:23 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 30D1B2080C for ; Thu, 1 Aug 2019 21:59:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="NFJ5mx3p" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 30D1B2080C Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 865F86B0003; Thu, 1 Aug 2019 17:59:22 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 83C986B0005; Thu, 1 Aug 2019 17:59:22 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 72B9B6B0006; Thu, 1 Aug 2019 17:59:22 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from mail-io1-f70.google.com (mail-io1-f70.google.com [209.85.166.70]) by kanga.kvack.org (Postfix) with ESMTP id 52D3E6B0003 for ; Thu, 1 Aug 2019 17:59:22 -0400 (EDT) Received: by mail-io1-f70.google.com with SMTP id h4so80923027iol.5 for ; Thu, 01 Aug 2019 14:59:22 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:dkim-signature:date:from:to:cc:subject :message-id:references:mime-version:content-disposition:in-reply-to :user-agent; bh=FlbNAsgaWkp1ShDCheHxAkj85en9Tu2y9Hru44fhYz0=; b=jmfgnhDd6agb1J36NPPR3DoL4weF4iVB1zmkJ2nD6EI5r/WlG6klx4ri4V8ei3z60J 0eNRcTIIrcIoYekv3bWdapMWb7jskyRDSUBfqxIMW2SdhVWJXLfcx+eiI8KxiKHREtMU DnX42NXIPHOfU/JgCrgugzLiTMjSArlWWNH/aLAyJK3CuVQqs72czsv6Oi/CpdouDND0 p/1PI3As2keFg6Ms26yDB4CM+zGRpKnnwZ6+HdrJsVpoGPzlE+BNxlenqwcMzqUslkb0 5Po2ZPguDWXfiUBG0/HI4a/8bxSD61mKgO8sa4+GQqLxvvAxr0pMLInlnLfms10jR5p4 p5vQ== X-Gm-Message-State: APjAAAUX4+k/QW9RY2DF/TGSzhxGEG4dbknWayyOsDAcg3O/ffHS+uRM dpvP7nU/Wo3bUXokg1Sj6LLZdt+27jxadEqo1KDJnYEVj9wvomdEj4oureTYYu09elz2c0BRA3T 5Zu/E3A190EmPFNgQ7FBUdApRxliUAp042Eo2w1rDn2/lkIrcvMMVNSdWNoh2RcmWwQ== X-Received: by 2002:a6b:f910:: with SMTP id j16mr314049iog.256.1564696762069; Thu, 01 Aug 2019 14:59:22 -0700 (PDT) X-Google-Smtp-Source: APXvYqxhjkk1nbAJMdgyHn2vhVzahAP2IBOBlFdNkdTlPoZYKmCKD4mvWnB15/yiRe8KwsQr5BP8 X-Received: by 2002:a6b:f910:: with SMTP id j16mr313970iog.256.1564696761111; Thu, 01 Aug 2019 14:59:21 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1564696761; cv=none; d=google.com; s=arc-20160816; b=Xgarl+Tw1lOpf7sEzQi57axIVOEcnLTNAV24d4rbd2/L6cRNcOzjTb3zP1cLSwqHJe HHsKi6IK/qhQz4Q6xKr40qzfFTIF/q5Z+dBpJEQaW1KtTHWtwGT+QtUrH7tihjEdHsSK SQ35vz2oMVbmCpNDl7H31903i+pXw/pPcW0f4c90M8qWBWSrLQm9OBzNDOac8Xx+yJ01 r1Pcv+mvWsy6KQwZq0W3wXcPceZ6AbeJ5Gkgs3GbHEygNg8FzCsQTfQuuf2j/Ru9uZVY oI4yuCmPZ87YfzEJmcJVw3WkvMMWyZ+kidj9dkp46VoMJoGD5cHUfPJnF0V4H1I2RB7+ wi4Q== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=google.com; s=arc-20160816; h=user-agent:in-reply-to:content-disposition:mime-version:references :message-id:subject:cc:to:from:date:dkim-signature; bh=FlbNAsgaWkp1ShDCheHxAkj85en9Tu2y9Hru44fhYz0=; b=evHmSEq2ios8XnH0NQbhSRSoQPI5xlXKr/eCSTWRBxtFKpOMMDNKDmG1UfKTg/ByhK 8+cp1eAOTDoPzoc6oE9ibRV2v6/Yg9n+m/UWg1/z/Tc4GNn7WSr6WGZcnJX3Avx/sN/r KEpcgWIuknKVLG989wNFwMIpmc1pkLcTE3FOVQ6MuIUdq+b6ONXFxJbCAK/HLlXqbM2x Q1CE1Ce7giSt0+k6soUfsl+TAFl9t0HNbi3uzhMvXA/USDdyFg21V4xTgLMJd1AgjeyW p5JSMs/AOLBhICUktqiqmht0jPQnw+waPW1sQIZnIbR0ZS9asyVNhLAlR33oY//ADClp 0FtA== ARC-Authentication-Results: i=1; mx.google.com; dkim=pass header.i=@infradead.org header.s=merlin.20170209 header.b=NFJ5mx3p; spf=pass (google.com: best guess record for domain of peterz@infradead.org designates 2001:8b0:10b:1231::1 as permitted sender) smtp.mailfrom=peterz@infradead.org Received: from merlin.infradead.org (merlin.infradead.org. [2001:8b0:10b:1231::1]) by mx.google.com with ESMTPS id q3si85349703ioj.22.2019.08.01.14.59.20 for (version=TLS1_3 cipher=AEAD-AES256-GCM-SHA384 bits=256/256); Thu, 01 Aug 2019 14:59:21 -0700 (PDT) Received-SPF: pass (google.com: best guess record for domain of peterz@infradead.org designates 2001:8b0:10b:1231::1 as permitted sender) client-ip=2001:8b0:10b:1231::1; Authentication-Results: mx.google.com; dkim=pass header.i=@infradead.org header.s=merlin.20170209 header.b=NFJ5mx3p; spf=pass (google.com: best guess record for domain of peterz@infradead.org designates 2001:8b0:10b:1231::1 as permitted sender) smtp.mailfrom=peterz@infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=merlin.20170209; h=In-Reply-To:Content-Type:MIME-Version: References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=FlbNAsgaWkp1ShDCheHxAkj85en9Tu2y9Hru44fhYz0=; b=NFJ5mx3pun9BIYphO0C68UAUu bNIl5t6nnsxHXQq8rOyvK1+2xENKG1banbuqonFceMoKyQfDoNijJJq1cmdDthZGkLdEJaHaa+JRR sy9AZHK01JafhzTXpLIhZcM24Nt52lWl/kRGtNf5E6LX5xx1DNeoa8ZNntincpMLRDHuDoi7WC/+y HA3O23EObKhT4TPP+bFOaHWWnfil3CE5Ggc/aCnZxceKFfwCToLfXOTGqgxuInpjTOEyU5G52eQ61 7gsEOZqcrfczHuU7P7Dx4ONddvwcraEmcYcTxxpMkFOgVNQGyPcL7cM+eMlCVnQ+Z2HDd9+SLiVEF If+0fSSdQ==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92 #3 (Red Hat Linux)) id 1htJ6I-0002fJ-Mv; Thu, 01 Aug 2019 21:59:07 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 51E57202953B0; Thu, 1 Aug 2019 23:59:04 +0200 (CEST) Date: Thu, 1 Aug 2019 23:59:04 +0200 From: Peter Zijlstra To: Suren Baghdasaryan Cc: Ingo Molnar , lizefan@huawei.com, Johannes Weiner , axboe@kernel.dk, Dennis Zhou , Dennis Zhou , Andrew Morton , linux-mm , linux-doc@vger.kernel.org, LKML , kernel-team , Nick Kralevich , Thomas Gleixner Subject: Re: [PATCH 1/1] psi: do not require setsched permission from the trigger creator Message-ID: <20190801215904.GC2332@hirez.programming.kicks-ass.net> References: <20190730013310.162367-1-surenb@google.com> <20190730081122.GH31381@hirez.programming.kicks-ass.net> <20190801095112.GA31381@hirez.programming.kicks-ass.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Aug 01, 2019 at 11:28:30AM -0700, Suren Baghdasaryan wrote: > > By marking it FIFO-99 you're in effect saying that your stupid > > statistics gathering is more important than your life. It will preempt > > the task that's in control of the band-saw emergency break, it will > > preempt the task that's adjusting the electromagnetic field containing > > this plasma flow. > > > > That's insane. > > IMHO an opt-in feature stops being "stupid" as soon as the user opted > in to use it, therefore explicitly indicating interest in it. However > I assume you are using "stupid" here to indicate that it's "less > important" rather than it's "useless". Quite; PSI does have its uses. RT just isn't one of them.