From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755083AbcKUUot (ORCPT ); Mon, 21 Nov 2016 15:44:49 -0500 Received: from one.firstfloor.org ([193.170.194.197]:52526 "EHLO one.firstfloor.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753478AbcKUUos (ORCPT ); Mon, 21 Nov 2016 15:44:48 -0500 Date: Mon, 21 Nov 2016 12:44:45 -0800 From: Andi Kleen To: Steven Rostedt Cc: Andi Kleen , Peter Zijlstra , Jiri Olsa , "Paul E. McKenney" , linux-kernel@vger.kernel.org, Ingo Molnar , Josh Triplett , Jan Stancek Subject: Re: [BUG] msr-trace.h:42 suspicious rcu_dereference_check() usage! Message-ID: <20161121204445.GX26852@two.firstfloor.org> References: <20161121005343.GB1891@krava> <20161121092850.GF3102@twins.programming.kicks-ass.net> <20161121170612.GT26852@two.firstfloor.org> <20161121171853.GK3092@twins.programming.kicks-ass.net> <20161121174504.GU26852@two.firstfloor.org> <20161121130115.2f0f38e7@gandalf.local.home> <20161121180654.GV26852@two.firstfloor.org> <20161121132220.17fb0515@gandalf.local.home> <20161121183700.GW26852@two.firstfloor.org> <20161121141517.31936dbe@gandalf.local.home> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161121141517.31936dbe@gandalf.local.home> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org > > http://halobates.de/tracepoint-trace > > There's a lot of push and pop regs due to function calling. There's > places that inlines can still improve things, and perhaps even some > likely unlikelys well placed. Assuming you avoid all the push/pop and all the call/ret this would only be ~25% of the total instructions. There is just far too much logic and computation in there. % awk ' { print $5 } ' tracepoint-trace | sort | uniq -c | sort -rn 222 mov 57 push 57 pop 35 test 34 cmp 32 and 28 jz 25 jnz 21 ret 20 call 16 lea 11 add -Andi