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[31.46.244.156]) by smtp.gmail.com with ESMTPSA id o7-20020a1c7507000000b004051f8d6207sm4207822wmc.6.2023.09.22.02.46.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 22 Sep 2023 02:46:19 -0700 (PDT) Date: Fri, 22 Sep 2023 11:46:17 +0200 From: Ingo Molnar To: Cyril Hrubis Message-ID: References: <20230901154355.5351-1-chrubis@suse.cz> <20230901174529.GB364687@pevik> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: X-Virus-Scanned: clamav-milter 1.0.1 at in-7.smtp.seeweb.it X-Virus-Status: Clean Subject: Re: [LTP] [PATCH] sched/rt: Disallow writing invalid values to sched_rt_period_us X-BeenThere: ltp@lists.linux.it X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux Test Project List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Juri Lelli , Valentin Schneider , Vincent Guittot , Peter Zijlstra , linux-kernel@vger.kernel.org, Steven Rostedt , Ben Segall , Ingo Molnar , Mel Gorman , Daniel Bristot de Oliveira , Dietmar Eggemann , ltp@lists.linux.it Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: ltp-bounces+ltp=archiver.kernel.org@lists.linux.it Sender: "ltp" * Cyril Hrubis wrote: > Hi! > > Documentation/scheduller/sched-rt-group.rst [1] specifies this as values from -1 to > > (INT_MAX - 1), I guess due int range. Looking into proc_dointvec_minmax() [2] > > even INT_MAX would pass the check. I suppose we can do nothing about that, > > because there is no value in sysctl_vals[] which would represent INT_MAX - 1. > > > > And you specify in LTP test range: from -1 to INT_MAX. > > > > But even much shorter value than INT_MAX fails: > > > > $ echo 1234567 > /proc/sys/kernel/sched_rt_runtime_us > > sh: echo: write error: Invalid argument > > That is because runtime_us must be < period_us by definition, since > runtime_us defines how much time is allocated from the period_us. I > guess that this is not described good enough in the kernel docs. Mind adding a second patch to your series, clarifying Documentation/scheduler/sched-rt-group.rst? Thanks, Ingo -- Mailing list info: https://lists.linux.it/listinfo/ltp 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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id D8C20CD4F43 for ; Fri, 22 Sep 2023 09:46:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232849AbjIVJqc (ORCPT ); Fri, 22 Sep 2023 05:46:32 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60760 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231755AbjIVJq2 (ORCPT ); Fri, 22 Sep 2023 05:46:28 -0400 Received: from mail-wm1-x32b.google.com (mail-wm1-x32b.google.com [IPv6:2a00:1450:4864:20::32b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 17D308F for ; Fri, 22 Sep 2023 02:46:22 -0700 (PDT) Received: by mail-wm1-x32b.google.com with SMTP id 5b1f17b1804b1-4053c6f1087so7927005e9.0 for ; Fri, 22 Sep 2023 02:46:22 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20230601; t=1695375980; x=1695980780; darn=vger.kernel.org; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:from:to:cc:subject:date:message-id :reply-to; bh=mUA/mCVKETHVeKPilnMQwh1npNRNUxijAiM43LdtxFw=; b=lS2R3yhIpiCcFLiTLtsSyq1/EXIdxkJLLP+Mx1Xw8DJR7xt6gIOQip/oMEz/y/b0Mq fygc3IJn9wszJkf0+mMt+e6SeZGtLVZMBo3KU6+ui3koFLW5HWT3zPRBWegjdpAtworr HvcO0OiYLW6pXK8cT7RUycOlTqZKA2DEX5DPbof6DQIL0QZYzdaXo5XnK/dBT3cQWToO 9yo8Im4woLP3x9tQ8niE33D3y/EgUdmYlMWEEwF4Z4Y2oY/Mh9N/sgIYSxhUwNRb1Fd4 4W92io9yEHZLVAm04A4s89wceEM81c0Xj0P4zEBZ0lHJQaTapn0/mTbtxQ51VOtU/bmF /jOQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1695375980; x=1695980780; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:sender:x-gm-message-state:from:to:cc :subject:date:message-id:reply-to; bh=mUA/mCVKETHVeKPilnMQwh1npNRNUxijAiM43LdtxFw=; b=gS94we8G0HMoBPAtIJ3jX2EbI2aKPUHq2OxuS5WFr79mgGPU4yOjEgaJFilGP/xVR1 eQp4WgKXnLtM4Wa0Xk9H9t/pjwh94OQO+y+jirc8bXgY8uV4I1mKuHypoUe9nKjIKsQo rMSCFtHtNquzIx+HQ10BUgxJk6vckaCHv3LtmTABa+OpwfZfs2t0CpneEaLlOJmteWll bM66eJl6HwoGpxvKG4RHVcN7xAs8bRw0okzfMUcbK9q6TJVqnstfB9mNaYs0AiusS3ax F/jWYBfoY27R/uWRgVMI3F/i2VkAvej7rjlRAKK49tusmC0n2PtQTUam6FytkUePWOxT 12wg== X-Gm-Message-State: AOJu0YxoOFFrB1VZnHXf7okXrX5Zwk1YjJNtB4bDULbCDlJ1fUo0Go8X ciInpSFrwmkPutoiiYuzkOg= X-Google-Smtp-Source: AGHT+IHC/lkFQ5wP8FgrtEHxdTFGpcGfLQxRq3yofp9mRyN/G33P5JRbEFkIhPDYYUj1v503ZbgOfA== X-Received: by 2002:a1c:6a04:0:b0:405:1baf:cedd with SMTP id f4-20020a1c6a04000000b004051bafceddmr6772220wmc.1.1695375980270; Fri, 22 Sep 2023 02:46:20 -0700 (PDT) Received: from gmail.com (1F2EF49C.nat.pool.telekom.hu. [31.46.244.156]) by smtp.gmail.com with ESMTPSA id o7-20020a1c7507000000b004051f8d6207sm4207822wmc.6.2023.09.22.02.46.19 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 22 Sep 2023 02:46:19 -0700 (PDT) Sender: Ingo Molnar Date: Fri, 22 Sep 2023 11:46:17 +0200 From: Ingo Molnar To: Cyril Hrubis Cc: Petr Vorel , Ingo Molnar , Peter Zijlstra , Juri Lelli , Vincent Guittot , Dietmar Eggemann , Steven Rostedt , Ben Segall , Mel Gorman , Daniel Bristot de Oliveira , Valentin Schneider , linux-kernel@vger.kernel.org, ltp@lists.linux.it Subject: Re: [LTP] [PATCH] sched/rt: Disallow writing invalid values to sched_rt_period_us Message-ID: References: <20230901154355.5351-1-chrubis@suse.cz> <20230901174529.GB364687@pevik> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org * Cyril Hrubis wrote: > Hi! > > Documentation/scheduller/sched-rt-group.rst [1] specifies this as values from -1 to > > (INT_MAX - 1), I guess due int range. Looking into proc_dointvec_minmax() [2] > > even INT_MAX would pass the check. I suppose we can do nothing about that, > > because there is no value in sysctl_vals[] which would represent INT_MAX - 1. > > > > And you specify in LTP test range: from -1 to INT_MAX. > > > > But even much shorter value than INT_MAX fails: > > > > $ echo 1234567 > /proc/sys/kernel/sched_rt_runtime_us > > sh: echo: write error: Invalid argument > > That is because runtime_us must be < period_us by definition, since > runtime_us defines how much time is allocated from the period_us. I > guess that this is not described good enough in the kernel docs. Mind adding a second patch to your series, clarifying Documentation/scheduler/sched-rt-group.rst? Thanks, Ingo