From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx163.postini.com [74.125.245.163]) by kanga.kvack.org (Postfix) with SMTP id 495946B0044 for ; Mon, 16 Apr 2012 05:44:07 -0400 (EDT) Message-ID: <4F8BE9D8.5060803@hitachi.com> Date: Mon, 16 Apr 2012 18:43:52 +0900 From: Masami Hiramatsu MIME-Version: 1.0 Subject: Re: [PATCH 3/3] tracing: Provide trace events interface for uprobes References: <20120416091936.19174.2641.sendpatchset@srdronam.in.ibm.com> <20120416091957.19174.22913.sendpatchset@srdronam.in.ibm.com> In-Reply-To: <20120416091957.19174.22913.sendpatchset@srdronam.in.ibm.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Srikar Dronamraju Cc: Peter Zijlstra , Ingo Molnar , Andrew Morton , Linus Torvalds , Ananth N Mavinakayanahalli , Jim Keniston , LKML , Linux-mm , Oleg Nesterov , Andi Kleen , Christoph Hellwig , Steven Rostedt , Arnaldo Carvalho de Melo , Thomas Gleixner , Anton Arapov (2012/04/16 18:19), Srikar Dronamraju wrote: > From: Srikar Dronamraju > > Implements trace_event support for uprobes. In its current form it can > be used to put probes at a specified offset in a file and dump the > required registers when the code flow passes through the probed address. > > The following example shows how to dump the instruction pointer and %ax > a register at the probed text address. Here we are trying to probe > zfree in /bin/zsh > > # cd /sys/kernel/debug/tracing/ > # cat /proc/`pgrep zsh`/maps | grep /bin/zsh | grep r-xp > 00400000-0048a000 r-xp 00000000 08:03 130904 /bin/zsh > # objdump -T /bin/zsh | grep -w zfree > 0000000000446420 g DF .text 0000000000000012 Base zfree > # echo 'p /bin/zsh:0x46420 %ip %ax' > uprobe_events > # cat uprobe_events > p:uprobes/p_zsh_0x46420 /bin/zsh:0x0000000000046420 > # echo 1 > events/uprobes/enable > # sleep 20 > # echo 0 > events/uprobes/enable > # cat trace > # tracer: nop > # > # TASK-PID CPU# TIMESTAMP FUNCTION > # | | | | | > zsh-24842 [006] 258544.995456: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > zsh-24842 [007] 258545.000270: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > zsh-24842 [002] 258545.043929: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > zsh-24842 [004] 258547.046129: p_zsh_0x46420: (0x446420) arg1=446421 arg2=79 > > Acked-by: Steven Rostedt > Signed-off-by: Srikar Dronamraju Looks good for me :) Acked-by: Masami Hiramatsu Thanks! -- Masami HIRAMATSU Software Platform Research Dept. Linux Technology Center Hitachi, Ltd., Yokohama Research Laboratory E-mail: masami.hiramatsu.pt@hitachi.com -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org