From mboxrd@z Thu Jan 1 00:00:00 1970 From: OSDepend Subject: Re: Re: Fw: Re: Re: Howto make perf probe work Date: Tue, 2 Apr 2013 17:11:01 +0800 Message-ID: <201304021710591525728@gmail.com> References: <201304010130139026692@gmail.com>, , <201304012320294652937@gmail.com>, <201304012324395211298@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset="gb2312" Content-Transfer-Encoding: 7bit Return-path: Received: from mail-da0-f46.google.com ([209.85.210.46]:45759 "EHLO mail-da0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760247Ab3DBJLG (ORCPT ); Tue, 2 Apr 2013 05:11:06 -0400 Received: by mail-da0-f46.google.com with SMTP id y19so106006dan.33 for ; Tue, 02 Apr 2013 02:11:06 -0700 (PDT) Sender: linux-perf-users-owner@vger.kernel.org List-ID: To: Namhyung Kim Cc: linux-perf-users , nelakurthi koteswararao Hi Kim, > > >HI, > > >Please enable kprobe_event config option in the kernel and build the same > > >and boot the board using it. Then please try to add event using perf probe > > >command > > > > Thanks very much for your reply, and I already enable DEBUG_KPROBE_EVENT in kernel. > > I did success in "perf probe handle_mm_fault". > > > > But when i want to to "perf probe" other Kernel symbol, such as do_page_fault. > > I came across other problems: > > Added new event: > > Failed to write event: Invalid argument > > Error: Failed to add events. (-1) > > And when i type perf probe page_fault_entry: > > Kernel symbol 'page_fault_entry' not found. > > Error: Failed to add events. (-2) > > Please notice that "do_page_fault" and "page_fault_entry" are all Kernel symbols, which canbe find in "/proc/kallsyms", but not recorgonized by perf (or even kprobe). > > Any idea for that? > For some reason, do_page_fault() is marked as __kprobe on some arch > which means it cannot be probed. > Thanks, > Namhyung My kernel is runing on X86_64 arch, is there any chance for me to get the do_page_fault() entry/exit work? Or How can i add a exit tracepoint for handle_mm_fault()? so I can calculate the latency of that fault handle function? Best, Chen