Re: [PATCH] x86: add the debugfs interface for the sysprof tool

From: Andrew Morton
Date: Sat Feb 23 2008 - 13:48:00 EST


On Sat, 23 Feb 2008 13:51:34 +0200 "Pekka Enberg" <penberg@xxxxxxxxxxxxxx> wrote:

> On Sat, Feb 23, 2008 at 10:11 AM, Andrew Morton
> <akpm@xxxxxxxxxxxxxxxxxxxx> wrote:
> > Seems a poor idea to me. Sure, oprofile is "hard to set up", but not if
> > your distributor already did it for you.
>
> Have you tried sysprof? It's really nice to setup and use compared to
> oprofile when profiling user-space.

Wanna see how I use oprofile?

box:/home/akpm> akpm-oprofile gcc t.c
Daemon not running
Daemon not running
Using 2.6+ OProfile kernel interface.
Reading module info.
Using log file /var/lib/oprofile/oprofiled.log
Daemon started.
Profiler running.
t.c:6:12: error: token ""x"" is not valid in preprocessor expressions

real 0m0.262s
user 0m0.004s
sys 0m0.004s
Stopping profiling.
Stopping profiling.
Killing daemon.
CPU: CPU with timer interrupt, speed 0 MHz (estimated)
Profiling through timer interrupt
samples % symbol name
625 99.2063 mwait_idle
1 0.1587 __handle_mm_fault
1 0.1587 clear_page
1 0.1587 do_page_fault
1 0.1587 flush_tlb_page
1 0.1587 pfn_valid
box:/home/akpm>


One thirteen-character command! Why? Because I actually got off my butt
and wrote a script to hide low-level details. I wrote the thing five years
ago and don't remember anything about what's in it.

I didn't need to write a new kernel module to enable that
thirteen-character shell script, and I don't believe one needs to write a
new kernel module to put a nice easy-to-use GUI around oprofile either.


This is one of those i-cant-believe-im-having-this-discussion discussions.
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