linux-kernel - Re: Ftrace: can trace kthread?

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite for Android: free password hash cracker in your pocket

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <1287651542.2237.17.camel@myhost>
Date:	Thu, 21 Oct 2010 16:59:02 +0800
From:	"Figo.zhang" <zhangtianfei@...dcoretech.com>
To:	Yong Zhang <yong.zhang0@...il.com>
Cc:	Li Zefan <lizf@...fujitsu.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Steven Rostedt <srostedt@...hat.com>
Subject: Re: Ftrace: can trace kthread?


> I just
> echo  0 > tracing_enabled
> echo function > current_tracer
> echo 374(pid of flush) > set_ftrace_pid
> echo 1 > tracing_enabled
> wait some time
> echo 0 > tracing_enabled
> cat trace
> 
> So I think this answer your question "could kthread be traced?"

i do it the same of you.

[root@...ost tracing]# ps -ax | grep flush
Warning: bad ps syntax, perhaps a bogus '-'? See http://procps.sf.net/faq.html
 1205 ?        S      0:01 [flush-8:0]
11852 pts/1    S+     0:00 grep flush
[root@...ost tracing]# 

so my flusher pid is 1205, i do it as below:

[root@...ost tracing]# echo 0 > tracing_enabled 
[root@...ost tracing]# echo function > current_tracer
[root@...ost tracing]# echo 1205 > set_ftrace_pid 
[root@...ost tracing]# echo 1 > tracing_enabled 

wait ... and open some pdf files, let system eat huge memory...

[root@...ost tracing]# echo 0 > tracing_enabled 
[root@...ost tracing]# cat trace
# tracer: function
#
#           TASK-PID    CPU#    TIMESTAMP  FUNCTION
#              | |       |          |         |


but i canot trace nothing. 


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/