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 DD969C433DB for ; Wed, 3 Feb 2021 14:06:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 9814164DDE for ; Wed, 3 Feb 2021 14:06:42 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232014AbhBCOF7 (ORCPT ); Wed, 3 Feb 2021 09:05:59 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49954 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232193AbhBCOFd (ORCPT ); Wed, 3 Feb 2021 09:05:33 -0500 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E3F57C0613D6 for ; Wed, 3 Feb 2021 06:04:52 -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=dbkLUfv83nI6Xflqb9q1zm/JmR8Ur/R/RfobV1RGkX4=; b=ZUkgLzNkSaDAXOtxyhACOs5Tz5 n/RKlEB1wOjYA9WO/+qh3T10NNf1+huaUNZ8FSHKu3gSLT78SG/XxJS7I66EDGtIAKLvAQGJCIl6s CSCOz9lXn3fkVbdArhcH/+6G6YWwia9NexOfsfWhR6MSBIPLvD/mMu158HUPW8tNE0Z31C/0PQGD6 fgpOM2cakouhZhZ7kl1GtU1Xrrx3GoDxXrAtVsTKo70YqZdCMcON6BiI+NAwSOZC8ScPkBT4kr0nS i3qPPm2HxGdslSxt0DbUKhI80Ym5DxlakHZ95UWUvFPCkmriRQDGUEDx06LZyC25Ig3L7pbzVVNi5 dsjSAVsw==; 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 1l7Ild-00GzO3-6T; Wed, 03 Feb 2021 14:04:27 +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 E2F3D3003D8; Wed, 3 Feb 2021 15:04:23 +0100 (CET) Received: by hirez.programming.kicks-ass.net (Postfix, from userid 1000) id BC68A284AA063; Wed, 3 Feb 2021 15:04:23 +0100 (CET) Date: Wed, 3 Feb 2021 15:04:23 +0100 From: Peter Zijlstra To: Josh Poimboeuf Cc: Frederic Weisbecker , LKML , Mel Gorman , Michal Hocko , Thomas Gleixner , "Paul E . McKenney" , Ingo Molnar , Michal Hocko , rostedt@goodmis.org, jbaron@akamai.com, ardb@kernel.org Subject: Re: [RFC PATCH 6/8] preempt/dynamic: Provide preempt_schedule[_notrace]() static calls Message-ID: References: <20210126235730.lgfa2uida5se5urn@treble> <20210127155914.jfmr4jay47yck5h5@treble> <20210127163308.cgiq7jxx2uziuhcc@treble> <20210127190003.64rdwoxyjgnq2rtx@treble> <20210127190218.hoztl7eidujqarkt@treble> <20210127231837.ifddpn7rhwdaepiu@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210127231837.ifddpn7rhwdaepiu@treble> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 27, 2021 at 05:18:37PM -0600, Josh Poimboeuf wrote: > On Wed, Jan 27, 2021 at 01:02:18PM -0600, Josh Poimboeuf wrote: > > On Wed, Jan 27, 2021 at 01:00:07PM -0600, Josh Poimboeuf wrote: > > > On Wed, Jan 27, 2021 at 07:44:01PM +0100, Peter Zijlstra wrote: > > > > On Wed, Jan 27, 2021 at 10:33:08AM -0600, Josh Poimboeuf wrote: > > > > > > > > > What did you think about .static_call_tramp_key? I could whip up a > > > > > patch later unless you beat me to it. > > > > > > > > Yeah, I'm not sure.. why duplicate information already present in > > > > kallsyms? > > > > > > Well, but it's not exactly duplicating kallsyms. No need to store > > > symbol names, just the pointer relationships. And kallsyms is > > > presumably slow. > > > > > > > There's a fair number of features that already require KALLSYMS, I can't > > > > really be bothered about adding one more (kprobes, function_tracer, > > > > stack_tracer, ftrace_syscalls). > > Here ya go. It builds... And the tramp_key section is nice and small. > > Relocation section [1497] '.rela.static_call_tramp_key' for section [1496] '.static_call_tramp_key' at offset 0x179ab818 contains 8 entries: > Offset Type Value Addend Name > 000000000000000000 X86_64_PC32 0x00000000000004c0 +0 __SCT__preempt_schedule > 0x0000000000000004 X86_64_PC32 0x000000000005ee10 +0 __SCK__preempt_schedule > 0x0000000000000008 X86_64_PC32 0x00000000000004c8 +0 __SCT__preempt_schedule_notrace > 0x000000000000000c X86_64_PC32 0x000000000005ee00 +0 __SCK__preempt_schedule_notrace > 0x0000000000000010 X86_64_PC32 0x00000000000004d0 +0 __SCT__cond_resched > 0x0000000000000014 X86_64_PC32 0x000000000005dd20 +0 __SCK__cond_resched > 0x0000000000000018 X86_64_PC32 0x00000000000004d8 +0 __SCT__might_resched > 0x000000000000001c X86_64_PC32 0x000000000005dd10 +0 __SCK__might_resched > Fair enough I suppose. I'll slap a changelog and your SoB on it and I suppose I'll got commit the whole lot. Then we can forget about it again.