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 0847FC77B7C for ; Mon, 1 May 2023 18:56:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232781AbjEASz6 (ORCPT ); Mon, 1 May 2023 14:55:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40146 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232625AbjEASz4 (ORCPT ); Mon, 1 May 2023 14:55:56 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id A88FAB6 for ; Mon, 1 May 2023 11:55:53 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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; bh=yxDleUQ2J/PiENXcRMI6lXFktbPZYkLi3wBEIWyspt0=; b=SsOr2pOerOAv1gTkFtKYOPCj5O Ohu8CHwIRetuJkbs/uuwVxcMs2fQvr3UKHPP309tBF33497Vmd+kviw0olEzyIPIpyfT7v7uw9zOm IaMgD56Sn85Y+wQzUA49MKY2vZuSfTDHyJNkRJUNsUvGRE+owe7bpXG0GGKcpsMZn3Ahz/Ew7W4B8 thJZ0/QHD46eLKvg0ri/XvlWouLn/hhSq4/qB3log6OlE8fTHvG5SobqrVWnYpEXf1f9vzQz0wKIH wf8EYNUdFjOUROStwCNKAyP3FWetlLeLJYutZmD4KYV+5yYgfqJiiGDyhZFVhn+bzRhwosSBbaGzI SCAnsRkQ==; Received: from j130084.upc-j.chello.nl ([24.132.130.84] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94.2 #2 (Red Hat Linux)) id 1ptYgR-007bFE-R2; Mon, 01 May 2023 18:55:35 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 403603002BF; Mon, 1 May 2023 20:55:34 +0200 (CEST) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 0018823C5C342; Mon, 1 May 2023 20:55:33 +0200 (CEST) Date: Mon, 1 May 2023 20:55:33 +0200 From: Peter Zijlstra To: chris hyser Cc: linux-kernel@vger.kernel.org, dietmar.eggemann@arm.com, vincent.guittot@linaro.org, Chen Yu , Ingo Molnar Subject: Re: [PATCH v4] sched/numa: Fix divide by zero for sysctl_numa_balancing_scan_size. Message-ID: <20230501185533.GD1597476@hirez.programming.kicks-ass.net> References: <20230406152633.3136708-1-chris.hyser@oracle.com> <20230429145635.GA1495785@hirez.programming.kicks-ass.net> <3fdc9c92-4a4f-b716-c8bc-056111feb3e0@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <3fdc9c92-4a4f-b716-c8bc-056111feb3e0@oracle.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 01, 2023 at 12:21:17PM -0400, chris hyser wrote: > In terms of actually wanting to fix this, I'm a bit confused. It clearly was > worth fixing the first time around (it has your sign-off), and the only > thing that has changed is that that fix no longer works. Well, the amount of effort to fix it has dramatically increased, 40+ extra lines vs 2 extra lines. > > If we do find we want this (why?!) then should we not invest in a better > > debugfs_create_u32_minmax() or something so that we don't get to add 40+ > > lines for everthing we want to add limits on? > > I will look at a way to greatly simplify the bounds checking here as you > suggest. Thanks, that might make it all a lot nicer indeed.