Re: [PATCH 0/2 v2] Syscalls tracing

[Ingo Molnar <mingo@elte.hu>]

* Ingo Molnar <mingo@elte.hu> wrote:

> 
> * Frederic Weisbecker <fweisbec@gmail.com> wrote:
> 
> > On Fri, Mar 13, 2009 at 03:42:10PM +0100, Frederic Weisbecker wrote:
> > > tracing/syscalls: core infrastructure to trace syscalls
> > > 
> > > This new iteration addresses a good part of the previous reviews.
> > 
> > 
> > Ah I just discovered that you applied the previous version 
> > today. But the v2 is not a delta :-s
> > 
> > I can rebase them but not until Sunday.
> 
> No problem, i'll deltify them and will have a look.

Ok, i did the deltas, tidied them up and put them into 
tip:tracing/syscalls.

Nice stuff! Here's some sample output:

aldebaran:/debug/tracing> head trace
# tracer: syscall
#
#           TASK-PID    CPU#    TIMESTAMP  FUNCTION
#              | |       |          |         |
           <...>-4405  [003]   188.452934: sys_dup2(oldfd: a, newfd: 1) 
           <...>-4405  [003]   188.452939: sys_dup2 -> 0x1
           <...>-4405  [003]   188.452940: sys_fcntl(fd: a, cmd: 1, arg: 0) 
           <...>-4405  [003]   188.452941: sys_fcntl -> 0x1
           <...>-4405  [003]   188.452942: sys_close(fd: a) 
           <...>-4405  [003]   188.452943: sys_close -> 0x0

A suggestion:

 - Would be nice for all the registered syscalls to show up
   under /debug/events/syscalls/, one directory per syscall,
   with an 'enable' and a 'format' file as well.

And a bugreport:

 - when using function_graph (after having used the syscall 
   tracer) i dont see graph traces anymore - only the syscall 
   trace entries:

# tracer: function_graph
#
# CPU  DURATION                  FUNCTION CALLS
# |     |   |                     |   |   |   |
##### CPU 9 buffer started ####
 at-spi-registry-3063  [009]   322.915058: sys_read -> 0x5a8
 at-spi-registry-3063  [009]   322.915059: sys_write(fd: 6, buf: 632840, count: 5a8) 
 at-spi-registry-3063  [009]   322.915062: sys_write -> 0x5a8
 at-spi-registry-3063  [009]   322.915062: sys_read(fd: 4, buf: 632840, count: 40000) 

That's not intended, right?

	Ingo