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=-8.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 B246CC4649B for ; Fri, 5 Jul 2019 11:52:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 6A42D218CD for ; Fri, 5 Jul 2019 11:52:22 +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="EpQvMvIb" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728717AbfGELwV (ORCPT ); Fri, 5 Jul 2019 07:52:21 -0400 Received: from merlin.infradead.org ([205.233.59.134]:34144 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728261AbfGELwU (ORCPT ); Fri, 5 Jul 2019 07:52:20 -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=6d4KHN3i4zXpEDjesjEyuvQqjM/+ziVHjS82Ev0bcAI=; b=EpQvMvIbfZTaXP1ube4rCEQrT NaO2RA66GKegqEQxIpC+saDSbZFKYAlrRsA3ozuyzG+JEGXQWANd0rAym6qjIg/fd7pOuLAMa7bdi TINN6LuTbp17kN8DlPy7FzCIa5QU/HsnO2Zbv42TCNJhbM+zG6DzQgyZk4AH9ZDI5ega/YvLtwqfD jLygNSIrQGsTXBnECgfMbWA+jZEp6qaZI6AuGp7jYrwkp8vSVsNQFzJgBkc3wpkuL+kaMlaWcNNnN eY5gUPOdcdS37PVvpdKWlY5dE01XUYN0S1KosAp/WDymMLcyVNJUu6oEN3s3fUrEbwWUqH3IMcBFQ FrFbRkkQw==; 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 1hjMlD-0001SU-Aw; Fri, 05 Jul 2019 11:52:16 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 707A02026E806; Fri, 5 Jul 2019 13:52:12 +0200 (CEST) Date: Fri, 5 Jul 2019 13:52:12 +0200 From: Peter Zijlstra To: Puranjay Mohan Cc: skhan@linuxfoundation.org, Ingo Molnar , "open list:SCHEDULER" , linux-kernel-mentees@lists.linuxfoundation.org Subject: Re: [PATCH] Sched: Change type of 'overrun' from int to u64 Message-ID: <20190705115212.GT3402@hirez.programming.kicks-ass.net> References: <20190705085609.24453-1-puranjay12@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190705085609.24453-1-puranjay12@gmail.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 Fri, Jul 05, 2019 at 02:26:09PM +0530, Puranjay Mohan wrote: > Callers of hrtimer_forward_now() should save the return value in u64. > function sched_rt_period_timer() stores > it in variable 'overrun' of type int > change type of overrun from int to u64 to solve the issue. Is there an actual issue? If we've missed _that_ many periods, something is really buggered. >From a code consistency PoV this patch makes sense, but I don't think there anything really wrong with the current code. > Signed-off-by: Puranjay Mohan > --- > kernel/sched/rt.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/kernel/sched/rt.c b/kernel/sched/rt.c > index 1e6b909dca36..f5d3893914f5 100644 > --- a/kernel/sched/rt.c > +++ b/kernel/sched/rt.c > @@ -19,7 +19,7 @@ static enum hrtimer_restart sched_rt_period_timer(struct hrtimer *timer) > struct rt_bandwidth *rt_b = > container_of(timer, struct rt_bandwidth, rt_period_timer); > int idle = 0; > - int overrun; > + u64 overrun; > > raw_spin_lock(&rt_b->rt_runtime_lock); > for (;;) { > -- > 2.21.0 >