Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752684AbcDZWKp (ORCPT ); Tue, 26 Apr 2016 18:10:45 -0400 Received: from merlin.infradead.org ([205.233.59.134]:44822 "EHLO merlin.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751986AbcDZWKl (ORCPT ); Tue, 26 Apr 2016 18:10:41 -0400 Date: Wed, 27 Apr 2016 00:10:17 +0200 From: Peter Zijlstra To: Brendan Gregg Cc: Arnaldo Carvalho de Melo , Alexei Starovoitov , David Ahern , Frederic Weisbecker , Ingo Molnar , Adrian Hunter , Alexander Shishkin , Alexei Starovoitov , He Kuang , Jiri Olsa , Masami Hiramatsu , Milian Wolff , Namhyung Kim , Stephane Eranian , Thomas Gleixner , Vince Weaver , Wang Nan , Zefan Li , Linux Kernel Mailing List Subject: Re: [PATCH/RFC v3] perf core: Allow setting up max frame stack depth via sysctl Message-ID: <20160426221017.GQ3430@twins.programming.kicks-ass.net> References: <20160425215947.GA25915@ast-mbp.thefacebook.com> <20160425234138.GA16708@kernel.org> <20160426000724.GA28705@ast-mbp.thefacebook.com> <20160426002928.GB16708@kernel.org> <20160426004358.GA29875@ast-mbp.thefacebook.com> <20160426004747.GC16708@kernel.org> <20160426210500.GK11033@kernel.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.21 (2012-12-30) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 434 Lines: 10 On Tue, Apr 26, 2016 at 02:58:41PM -0700, Brendan Gregg wrote: > BTS seemed more promising (deeper stacks), and there's already Xen > support for it (need to boot the Xen host with vpmu=bts, preferably > vpmu=bts,arch for some PMCs as well :). BTS is a branch tracer; it simply traces _all_ branches, including calls. It has fairly significant overhead. But yes, by tracing all branches, you should get really shiny call traces :-)