gprof & Linux interaction oddity

gprof & Linux interaction oddity

[Tres Melton]

Gentlemen,

	There is an issue with gprof and getting the current OS' Hz from the
elf header in Linux via sysconf().  That value is always set to 100 Hz
and it is playing games with profiling code. I have been in contact with
a number of the kernel developers and we are preparing to take this
issue to the LKML.  There is a bug on RedHat's bugzilla regarding this
issue and a more detailed report in Gentoo's bugzilla:

http://bugs.gentoo.org/show_bug.cgi?id=90090
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=151763

	Most of the developers that I have spoken with, including Andrew Morton
and John Mylchreest, are in favor of correcting this issue but Linus has
previously ruled against it.  We are hoping that he will reconsider
since the merging of the configurable user hz patch in 2.6.13-rc3.

	One of the developers, Robert Love, has responded:  "Explain why gprof
needs to know the _actual_ timing tick."  I was hoping that you could
help me with that.

Thanks for your help,
-- 
Tres

Re: gprof & Linux interaction oddity

[Daniel Jacobowitz]

Gprof has nothing to do with GDB, sorry.

On Sun, Jul 24, 2005 at 02:56:57PM -0600, Tres Melton wrote:
> 	One of the developers, Robert Love, has responded:  "Explain why gprof
> needs to know the _actual_ timing tick."  I was hoping that you could
> help me with that.

I am inclined to agree with Robert, but I haven't investigated in
depth, and don't care to.

-- 
Daniel Jacobowitz
CodeSourcery, LLC