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=-6.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, 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 5F334C433DB for ; Wed, 27 Jan 2021 19:04:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 09B7760C3D for ; Wed, 27 Jan 2021 19:04:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1344461AbhA0TEe (ORCPT ); Wed, 27 Jan 2021 14:04:34 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:28110 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1344382AbhA0TDx (ORCPT ); Wed, 27 Jan 2021 14:03:53 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1611774147; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=WizI47Xyqf1zm2sS3CIOE1WP48Ua/+LDqcbLFZV+d6M=; b=DoL3rMVFFl2LHtLV6eitZLN+vZlxG4GDTS81+wHiUtj5imt7uMKAUCGUmqcHa7z5kEc5Mo bTUyesup3k7l1Jphul9BFbC8DHGsset4+N8Yd+/V9WYjlhhVRZOaWI3EHFNMMju/QE/okt cjFXw/BfP2hpEmov8z/zADqMxnbBXmE= Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-211-KTXk0u4YPqWqWDJorZYdYg-1; Wed, 27 Jan 2021 14:02:23 -0500 X-MC-Unique: KTXk0u4YPqWqWDJorZYdYg-1 Received: from smtp.corp.redhat.com (int-mx02.intmail.prod.int.phx2.redhat.com [10.5.11.12]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx01.redhat.com (Postfix) with ESMTPS id 06F5F107ACE4; Wed, 27 Jan 2021 19:02:22 +0000 (UTC) Received: from treble (ovpn-120-118.rdu2.redhat.com [10.10.120.118]) by smtp.corp.redhat.com (Postfix) with ESMTPS id AF45B60BF3; Wed, 27 Jan 2021 19:02:20 +0000 (UTC) Date: Wed, 27 Jan 2021 13:02:18 -0600 From: Josh Poimboeuf To: Peter Zijlstra 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: <20210127190218.hoztl7eidujqarkt@treble> References: <20210118141223.123667-7-frederic@kernel.org> <20210122165226.GD16371@worktop.programming.kicks-ass.net> <20210126235730.lgfa2uida5se5urn@treble> <20210127155914.jfmr4jay47yck5h5@treble> <20210127163308.cgiq7jxx2uziuhcc@treble> <20210127190003.64rdwoxyjgnq2rtx@treble> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210127190003.64rdwoxyjgnq2rtx@treble> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.12 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 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). > > Right, but I don't think they rely on KALLSYMS_ALL? Scratch that, I forgot about your last hack. (That's what I get for emailing during meetings.) I mean - your patch is fine... let me just whip up the alternative and we can compare. -- Josh