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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_PASS,URIBL_BLOCKED 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 723F3C43441 for ; Fri, 23 Nov 2018 23:09:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3105320861 for ; Fri, 23 Nov 2018 23:09:47 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3105320861 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=linux-foundation.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 S1727606AbeKXJzz (ORCPT ); Sat, 24 Nov 2018 04:55:55 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:41092 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727435AbeKXJzz (ORCPT ); Sat, 24 Nov 2018 04:55:55 -0500 Received: from localhost.localdomain (c-24-6-170-16.hsd1.ca.comcast.net [24.6.170.16]) by mail.linuxfoundation.org (Postfix) with ESMTPSA id C67A2ACA; Fri, 23 Nov 2018 23:09:44 +0000 (UTC) Date: Fri, 23 Nov 2018 15:09:43 -0800 From: Andrew Morton To: Mark Rutland Cc: linux-kernel@vger.kernel.org, mingo@kernel.org, Boqun Feng , Borislav Petkov , Peter Zijlstra , Will Deacon Subject: Re: [PATCH] locking/atomics: build atomic headers as required Message-Id: <20181123150943.ddf22393b568131a3383fd02@linux-foundation.org> In-Reply-To: <20181123153321.8561-1-mark.rutland@arm.com> References: <20181123153321.8561-1-mark.rutland@arm.com> X-Mailer: Sylpheed 3.5.1 (GTK+ 2.24.31; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 23 Nov 2018 15:33:21 +0000 Mark Rutland wrote: > Andrew and Ingo report that the check-atomics.sh script is simply too > slow to run for every kernel build, and it's impractical to make it > faster without rewriting it in something other than shell. > > Rather than committing the generated headers, let's regenerate these > as-required for a pristine tree. > > That ensures they're always up-to-date, allows them to be built in > parallel, and avoid redundant rebuilds, which is a 2-8s saving per > incremental build. Since the results are not committed, it's very > obvious that they should not be modified directly. If we need to > generate more headers in future, it's easy to extend Makefile.genheader > to permit this. > > I've verified that this works in the cases we previously had issues with > (out-of-tree builds and where scripts have no execute permissions), and > have tested these cases for both x86_64 and arm64. Seems like a reasonable compromise. I'll take a copy for testing now, shall drop that when this appears in tip->linux-next.