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=-5.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS autolearn=no 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 4A038C43381 for ; Tue, 9 Mar 2021 21:25:38 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1D47F6528A for ; Tue, 9 Mar 2021 21:25:38 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232021AbhCIVZH (ORCPT ); Tue, 9 Mar 2021 16:25:07 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:36106 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231607AbhCIVZD (ORCPT ); Tue, 9 Mar 2021 16:25:03 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 77FE0C06174A for ; Tue, 9 Mar 2021 13:25:03 -0800 (PST) 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=LgewzQA3xUk9kmLICc7ceJEbICsBxv0UaXPJiUdEAuA=; b=mMVewxL/w883DRQutIv8BNJrRw DTjbUWuy/ChVtWQKXCxM4/2tfg4nVOGTX+f5GG9KC+GtWutNT0TT5GZWrKrZM56gpfnmfnSSUI0hi wZqCTer7zdfSwVEO6LRgKIgfNrnwXYELJpeSYIhh27z1BgGqFwAq9TNjo/fv4MKgKG8fbmC0cq9Nh EznC//2wB1fUHHtlbEnh3Od0UAdPi1xvrfoJNnG9IlWJ6tCAxgBItRwM+e43tLv/VXhUbz/jS/Ych wqvVyHwDC12aV1WmIUbdWFLf6gf5K03duFpw/RBLaGCripXJ/tdAlu8PJl1wBHzC0tb7EfrZYP5ta zu51Xi4g==; Received: from j217100.upc-j.chello.nl ([24.132.217.100] helo=noisy.programming.kicks-ass.net) by casper.infradead.org with esmtpsa (Exim 4.94 #2 (Red Hat Linux)) id 1lJjqP-001R0d-SW; Tue, 09 Mar 2021 21:24:48 +0000 Received: from hirez.programming.kicks-ass.net (hirez.programming.kicks-ass.net [192.168.1.225]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by noisy.programming.kicks-ass.net (Postfix) with ESMTPS id 758283010CF; Tue, 9 Mar 2021 22:24:44 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id 33EAD2027A4B1; Tue, 9 Mar 2021 22:24:44 +0100 (CET) Date: Tue, 9 Mar 2021 22:24:44 +0100 From: Peter Zijlstra To: Steven Rostedt Cc: x86@kernel.org, linux-kernel@vger.kernel.org, "H. Peter Anvin" Subject: Re: The killing of ideal_nops[] Message-ID: References: <20210309120519.7c6bbb97@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210309120519.7c6bbb97@gandalf.local.home> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Mar 09, 2021 at 12:05:19PM -0500, Steven Rostedt wrote: > On Tue, 9 Mar 2021 17:58:17 +0100 > Peter Zijlstra wrote: > > > Hi, > > > > AFAICT everything made in the past 10 years ends up using p6_nops. Is it > > time to kill off ideal_nops[] and simplify life? > > > > Well, the one bug that was reported recently was due to a box that uses a > different "ideal_nops" than p6_nops. Perhaps we should ask him if there's > any noticeable difference between using p6_nops for every function than the > ideal_nops that as found for that box. If the machine is more than a decade old, I'm not really caring about optimal performance. If it is 32bit, I really couldn't be arsed as long as it boots.