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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,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 EF1BDC10F12 for ; Wed, 17 Apr 2019 07:13:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B59EC204FD for ; Wed, 17 Apr 2019 07:13:23 +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="aovxQVXA" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731053AbfDQHNW (ORCPT ); Wed, 17 Apr 2019 03:13:22 -0400 Received: from merlin.infradead.org ([205.233.59.134]:53896 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727013AbfDQHNW (ORCPT ); Wed, 17 Apr 2019 03:13:22 -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=ay6pB6Tao4Oq8JNPjAEYYOWN5BO2WLe+exSGHeFUb9g=; b=aovxQVXAIDWql2opzekWL9IKc ZiQHOQe2VfXodYFiWW3TP/AZT18u0n9Xxr25nPVWcQiBqNl2TshVj4ycDuH+fMJ5iHKo4hp0q91pW SJmRr4Hol9lHgNCc8+Ls56QjqwXVeQ3wLs2Nz3IA+KRe6YwnfQ0yPZoAwxo8vjL3ejiD/vq3/tMj3 nEJ0Aep+iz+GwcoDi0rIZL8RZUFkz23bXqm2k4jc09nn6MZFLQBIPmbCnBFyCeuBlcWtZv7CrpRnI XY6a6e7uRFZjx3HTW4lT5rm78PONwKBtYZRuJt5w9XlyA973w4eqnqNI7eByWWq2FBgH0MLYAZNWM FpT5UG/EQ==; 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 1hGekm-0005ey-Vl; Wed, 17 Apr 2019 07:13:09 +0000 Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 910FD200BFB38; Wed, 17 Apr 2019 09:13:06 +0200 (CEST) Date: Wed, 17 Apr 2019 09:13:06 +0200 From: Peter Zijlstra To: Waiman Long Cc: Ingo Molnar , Will Deacon , Thomas Gleixner , linux-kernel@vger.kernel.org, x86@kernel.org, Davidlohr Bueso , Linus Torvalds , Tim Chen , huang ying Subject: Re: [PATCH v4 07/16] locking/rwsem: Implement lock handoff to prevent lock starvation Message-ID: <20190417071306.GX4038@hirez.programming.kicks-ass.net> References: <20190413172259.2740-1-longman@redhat.com> <20190413172259.2740-8-longman@redhat.com> <20190416141205.GK12232@hirez.programming.kicks-ass.net> <4b36b0a5-8507-f90c-d4a7-3f821ee8da6d@redhat.com> <55474839-269f-4dbc-23af-a9c873db6c66@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <55474839-269f-4dbc-23af-a9c873db6c66@redhat.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 Tue, Apr 16, 2019 at 05:07:26PM -0400, Waiman Long wrote: > Thinking about it again. I think I will just change its definition to > "((HZ + 249)/250)" for now to make sure that it is at least 1. The DIV_ROUND_UP()