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_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, URIBL_BLOCKED,USER_AGENT_MUTT autolearn=ham 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 3DB8FECDFB1 for ; Tue, 17 Jul 2018 15:18:13 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E32CC20850 for ; Tue, 17 Jul 2018 15:18:12 +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="Ne0Ga0qA" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E32CC20850 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729727AbeGQPvR (ORCPT ); Tue, 17 Jul 2018 11:51:17 -0400 Received: from merlin.infradead.org ([205.233.59.134]:44012 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728489AbeGQPvR (ORCPT ); Tue, 17 Jul 2018 11:51:17 -0400 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=T7QQXWJik7DIMUKOPsZKkZ2/AC27bc8CIYb94GWwwTA=; b=Ne0Ga0qAPKBQCjZK8R17N0XCO RBiAEIDk2nJ58HvJr2wtPmomGJXKqRPFJGuQ+K6y5j2nAMhumZAYeJYONf9LSNChxETxrzDSNnT2g juDgHnZXP3/GKVz/5n9hY+Cx/AYHeWZDvtgbIOT4EE4TY2GjCj0WLKdOWjO6+dTifjHT3qZgoLG2B Pia0hQ/7S8y+ITNwDe50HS8Hu5r0FQJEXio74ntjwEpSs/f9GSUeqfpWDqOGA4UzeeGJHsdj2Ft6r ipNHqdprVX0L4Z0gr2w/WE9JfQL/8Irl8XVYHSctnlzKd3xn0F/5kvxXXWv7JaSKVnIcT43xsZbnE ilySMeVmA==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=hirez.programming.kicks-ass.net) by merlin.infradead.org with esmtpsa (Exim 4.90_1 #2 (Red Hat Linux)) id 1ffRjk-0001GW-0H; Tue, 17 Jul 2018 15:18:00 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id BB5BF20289332; Tue, 17 Jul 2018 17:17:58 +0200 (CEST) Date: Tue, 17 Jul 2018 17:17:58 +0200 From: Peter Zijlstra To: Arnd Bergmann Cc: akpm@linux-foundation.org, Ingo Molnar , Stephen Rothwell , Johannes Weiner , linux-kernel@vger.kernel.org Subject: Re: [PATCH] psi-pressure-stall-information-for-cpu-memory-and-io-fix-fix-fix Message-ID: <20180717151758.GI2494@hirez.programming.kicks-ass.net> References: <20180717135133.3627980-1-arnd@arndb.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180717135133.3627980-1-arnd@arndb.de> User-Agent: Mutt/1.10.0 (2018-05-17) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 17, 2018 at 03:51:24PM +0200, Arnd Bergmann wrote: > The addition of do_div() did not do the right thing, as it assigned the > result of the multiplication to an 'unsigned long', which truncates > it before the division. GCC warns in various ways about this depending > on the architecuture, e.g. > > arch/arm/include/asm/div64.h:33:45: note: expected 'uint64_t *' {aka 'long long unsigned int *'} but argument is of type 'long unsigned int *' > > This uses div_u64() instead. This is probably still a bad idea since > we should avoid 64-bit division altogether in the scheduler, but at > least it does the correct calculation. > > Fixes: 13a67bcb35f5 ("psi-pressure-stall-information-for-cpu-memory-and-io-fix-fix") > Signed-off-by: Arnd Bergmann > --- > Please fold into the fix Please drop the entire PSI series instead.