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=-2.0 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 33D6FC282DD for ; Fri, 10 Jan 2020 13:42:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 065682080D for ; Fri, 10 Jan 2020 13:42:59 +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="iQ+UspVX" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728301AbgAJNm6 (ORCPT ); Fri, 10 Jan 2020 08:42:58 -0500 Received: from merlin.infradead.org ([205.233.59.134]:40296 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728226AbgAJNm5 (ORCPT ); Fri, 10 Jan 2020 08:42:57 -0500 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=GYGF/a4qRWroP/Y/H4KPJyAQgKptGfA1ZmohXqWNKSA=; b=iQ+UspVXX1HEG+w2HZ5QjJauD MOgh04LefdeXka9JjPakR5ZwXGMxxwoMqVtzLmS+0IlQ+rxmVjXgituwUKia9I4yyLztfQa7I5JOi lOljcymFY6l8mT9sBFx5yocFX5VQRisY2pU7VmXAYjgabjBCHphK4LJU0p4pmDybipvCArejlAPYz O8IR7/chn/iknXFupNZzt0qtbVmdUMxc11plVOLGeTb6KperE2MryVCihcyFxtZDwGIpxwqpY+iDQ 60wfxwfalJkdp4R80n8/ZaKISh99WqpkW5Oq/D0JeUG/XkPzeTUU/e+9wP5uW6s7QnK1gLW7moqWG aL8Jd+aUw==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.92.3 #3 (Red Hat Linux)) id 1ipuYg-0003gY-P0; Fri, 10 Jan 2020 13:42:38 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 0D71E30025A; Fri, 10 Jan 2020 14:41:03 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id F027C2B612615; Fri, 10 Jan 2020 14:42:36 +0100 (CET) Date: Fri, 10 Jan 2020 14:42:36 +0100 From: Peter Zijlstra To: Qais Yousef Cc: Ingo Molnar , Dietmar Eggemann , Steven Rostedt , Luis Chamberlain , Kees Cook , Iurii Zaikin , Juri Lelli , Vincent Guittot , Ben Segall , Mel Gorman , valentin.schneider@arm.com, qperret@google.com, Patrick Bellasi , linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH] sched/rt: Add a new sysctl to control uclamp_util_min Message-ID: <20200110134236.GM2844@hirez.programming.kicks-ass.net> References: <20191220164838.31619-1-qais.yousef@arm.com> <20200108134448.GG2844@hirez.programming.kicks-ass.net> <20200109130052.feebuwuuvwvm324w@e107158-lin.cambridge.arm.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200109130052.feebuwuuvwvm324w@e107158-lin.cambridge.arm.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Jan 09, 2020 at 01:00:58PM +0000, Qais Yousef wrote: > On 01/08/20 14:44, Peter Zijlstra wrote: > > Did cpu_uclamp_write() forget to check for input<0 ? > > Hmm just tried that and it seems so > > # echo -1 > cpu.uclamp.min > # cat cpu.uclamp.min > 42949671.96 > > capacity_from_percent(); we check for > > 7301 if (req.percent > UCLAMP_PERCENT_SCALE) { > 7302 req.ret = -ERANGE; > 7303 return req; > 7304 } > > But req.percent is s64, maybe it should be u64? if ((u64)req.percent > UCLAMP_PERCENT_SCALE) should do, I think.