From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932194Ab0AFNIR (ORCPT ); Wed, 6 Jan 2010 08:08:17 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754819Ab0AFNIQ (ORCPT ); Wed, 6 Jan 2010 08:08:16 -0500 Received: from mx1.redhat.com ([209.132.183.28]:64381 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754204Ab0AFNIP (ORCPT ); Wed, 6 Jan 2010 08:08:15 -0500 Date: Wed, 6 Jan 2010 14:08:06 +0100 From: Jiri Olsa To: Lai Jiangshan Cc: Steven Rostedt , Frederic Weisbecker , LKML Subject: Re: tracing: confusing output of function_graph when notrace function calls traceable function Message-ID: <20100106130806.GA7682@jolsa.lab.eng.brq.redhat.com> References: <4B446972.9050901@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <4B446972.9050901@cn.fujitsu.com> User-Agent: Mutt/1.5.20 (2009-08-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jan 06, 2010 at 06:44:02PM +0800, Lai Jiangshan wrote: > cat /tracing/trace > you can get these at the end of the outputs: > > 1) | nameidata_to_filp() { > 1) | __dentry_open() { > 1) | file_move() { > 1) 0.834 us | _raw_spin_lock(); > 1) 0.926 us | _raw_spin_unlock(); > 1) 4.768 us | } > > !!!! file_move() is really called by __dentry_open() > > 1) | kmem_cache_alloc_notrace() { > 1) 5.879 us | memset(); > 1) + 12.390 us | } > 1) 1.025 us | mutex_lock(); > 1) | kmem_cache_alloc_notrace() { > 1) 0.929 us | memset(); > 1) 3.329 us | } > 1) 1.195 us | memcpy(); > 1) 1.026 us | __mutex_init(); > > !!!! the above are actually called by __tracing_open() which called by __dentry_open() > (But at the first I was confused, I wondered why __dentry_open() calls them.) > > 1) | kmem_cache_alloc_notrace() { > 1) 0.978 us | memset(); > 1) 2.745 us | } > 1) | __alloc_percpu() { > 1) | pcpu_alloc() { > 1) 1.053 us | mutex_lock(); > 1) 1.282 us | _raw_spin_lock_irqsave(); > 1) | pcpu_size_to_slot() { > 1) 0.819 us | __pcpu_size_to_slot(); > 1) 5.455 us | } > 1) 1.135 us | pcpu_need_to_extend(); > 1) | pcpu_alloc_area() { > 1) | pcpu_chunk_slot() { > 1) | pcpu_size_to_slot() { > 1) 0.813 us | __pcpu_size_to_slot(); > 1) 2.535 us | } > 1) 8.349 us | } > 1) 1.160 us | memmove(); > 1) | pcpu_chunk_relocate() { > 1) | pcpu_chunk_slot() { > 1) | pcpu_size_to_slot() { > 1) 0.803 us | __pcpu_size_to_slot(); > 1) 2.478 us | } > 1) 4.129 us | } > 1) 8.583 us | } > 1) + 29.665 us | } > 1) 1.038 us | _raw_spin_unlock_irqrestore(); > 1) 1.178 us | pcpu_next_pop(); > 1) 1.087 us | pcpu_chunk_addr(); > 1) 0.975 us | memset(); > 1) 0.821 us | pcpu_chunk_addr(); > 1) 0.943 us | memset(); > 1) 0.896 us | mutex_unlock(); > 1) + 75.625 us | } > 1) + 77.453 us | } > > !!!! the above are actually called by graph_trace_open() which called by __tracing_open() > > == real graph ==: > > father_fun() > child_fun() > notrace_child_fun() > grandchild_fun1() > grandchild_fun2() > > ===function_graph shows===> > > father_fun() > child_fun() > grandchild_fun1() > grandchild_fun2() > > When the notrace function calls traceable function, function_graph will > get wrong depth of functions, and show wrong graph. > > Is there any method to fix it? I dont think so.. AFAIK the depth computation is based on the traced functions, and there's no other 'depth related' input apart from them. jirka > > Lai > -- > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > Please read the FAQ at http://www.tux.org/lkml/