Confusing help regarding single-depth WCHAN output

From: RogÃrio Brito
Date: Sun Aug 09 2009 - 11:16:56 EST


Hi.

I noticed this some releases ago, but only now I was perusing the kernel
with a little more attention and got very curious. When doing a "make
menuconfig" on an amd64 system, I get the following message:

,----
| Single-depth WCHAN output
| CONFIG_SCHED_OMIT_FRAME_POINTER:
|
| Calculate simpler /proc/<PID>/wchan values. If this option
| is disabled then wchan values will recurse back to the
| caller function. This provides more accurate wchan values,
| at the expense of slightly more scheduling overhead.
|
| If in doubt, say "Y".
|
| Symbol: SCHED_OMIT_FRAME_POINTER [=y]
| Prompt: Single-depth WCHAN output
| Defined at arch/x86/Kconfig:441
| Depends on: X86
| Location:
| -> Processor type and features
`----

Is the WCHAN option related to omitting a frame pointer? If yes, how
could this be written in a more detailed way?


Thanks for any comments, RogÃrio Brito.

--
RogÃrio Brito : rbrito@{mackenzie,ime.usp}.br : GPG key 1024D/7C2CAEB8
http://www.ime.usp.br/~rbrito : http://meusite.mackenzie.com.br/rbrito
Projects: algorithms.berlios.de : lame.sf.net : vrms.alioth.debian.org
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/