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 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 8B209C43441 for ; Fri, 9 Nov 2018 19:59:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 54DB520855 for ; Fri, 9 Nov 2018 19:59:23 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 54DB520855 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=goodmis.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 S1728086AbeKJFl0 (ORCPT ); Sat, 10 Nov 2018 00:41:26 -0500 Received: from mail.kernel.org ([198.145.29.99]:52032 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725788AbeKJFl0 (ORCPT ); Sat, 10 Nov 2018 00:41:26 -0500 Received: from gandalf.local.home (cpe-66-24-56-78.stny.res.rr.com [66.24.56.78]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 7A59020825; Fri, 9 Nov 2018 19:59:19 +0000 (UTC) Date: Fri, 9 Nov 2018 14:59:18 -0500 From: Steven Rostedt To: Josh Poimboeuf Cc: Andy Lutomirski , Andy Lutomirski , Ingo Molnar , LKML , X86 ML , Ard Biesheuvel , Peter Zijlstra , Thomas Gleixner , Linus Torvalds , Masami Hiramatsu , Jason Baron , Jiri Kosina , David Laight , Borislav Petkov Subject: Re: [PATCH RFC 0/3] Static calls Message-ID: <20181109145918.28df6616@gandalf.local.home> In-Reply-To: <20181109194409.mnrzdee6gh4ujutm@treble> References: <20181109072811.GB86700@gmail.com> <20181109152139.zig45f6gp24btfbc@treble> <20181109164137.5cngbfrkm4ihj4ra@treble> <20181109134241.5f4ce3be@gandalf.local.home> <979DB163-EFBD-41BB-8481-155AAF526E72@amacapital.net> <20181109143703.5f2205bf@gandalf.local.home> <20181109194409.mnrzdee6gh4ujutm@treble> X-Mailer: Claws Mail 3.16.0 (GTK+ 2.24.32; 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, 9 Nov 2018 13:44:09 -0600 Josh Poimboeuf wrote: > On Fri, Nov 09, 2018 at 02:37:03PM -0500, Steven Rostedt wrote: > > On Fri, 9 Nov 2018 11:05:51 -0800 > > Andy Lutomirski wrote: > > > > > > Not sure what Andy was talking about, but I'm currently implementing > > > > tracepoints to use this, as tracepoints use indirect calls, and are a > > > > prime candidate for static calls, as I showed in my original RFC of > > > > this feature. > > > > > > > > > > > > > > Indeed. > > > > > > Although I had assumed that tracepoints already had appropriate jump label magic. > > > > It does. But that's not the problem I was trying to solve. It's that > > tracing took a 8% noise dive with retpolines when enabled (hackbench > > slowed down by 8% with all the trace events enabled compared to all > > trace events enabled without retpoline). That is, normal users (those > > not tracinng) are not affected by trace events slowing down by > > retpoline. Those that care about performance when they are tracing, are > > affected by retpoline, quite drastically. > > > > I'm doing another test run and measurements, to see how the unoptimized > > trampolines help, followed by the trampoline case. > > Are you sure you're using unoptimized? Optimized is the default on > x86-64 (with my third patch). > Yes, because I haven't applied that third patch yet ;-) Then I'll apply it and see how much that improves things. -- Steve