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Re: Some (small) c++ compilation profiling data (oprofile)
- From: Will Cohen <wcohen at redhat dot com>
- To: Karel Gardas <kgardas at objectsecurity dot com>
- Cc: gcc at gcc dot gnu dot org
- Date: Fri, 17 May 2002 14:03:53 -0400
- Subject: Re: Some (small) c++ compilation profiling data (oprofile)
- Organization: Red Hat, Inc.
- References: <Pine.LNX.email@example.com>
I have a Dell Inpiron 4100 with a 1 GHz mobile Pentium III and oprofile
is using the mobile Pentium III performance monitoring hardware.
What kind of processor does oprofile think the machine has? The
following command should return a number:
I would expect this return "2" for a Pentium III based on enum for
op_cpu in oprofile/libop/op_interface.h. oprofile has some code to
determine the processor type. It is possible that it isn't identifying
the processor. If oprofile cannot identify the processor, it assumes
CPU_RTC (should be "4"). The /proc/cpuinfo should provide some clues
with information about "cpu family" and "model".
Karel Gardas wrote:
> On Fri, 17 May 2002, Will Cohen wrote:
>>Profiling and characterization of gcc by oprofile would be very useful.
>>The cvs version of oprofile has a "--reverse" option for oprofpp, which
> Thanks, I'll use it in the future reports.
>>What environment (hardware and software) did you use to take these
>>measurements? Ideally, someone else should be able to reproduce and
>>verify the result. GCC is a moving target, the cvs tag used to check
>>out the code should be included. Is the bootstrapped compiler being used
>>for the tests? If just the stage1 compiler is being used, the compiler
>>used to build the GCC being profiled can influence the measurements.
> I've meassured gcc 3.1 (release) bootstraped with standard 3 stage
> bootstrap. Since I'm learning oprofile now, I've used standard
> configuration and so header of tables look:
> Cpu type: CPU with RTC device
> Cpu speed was (MHz estimation) : 995.685000
> Counter 0 counted RTC_Interrupts events (RTC interrupts/sec (rounded up to power of two)) count 1024
> vma samples %-age symbol name
> 080496f0 0 0 _start
> 08049714 0 0 Letext
> Machine is notebook (apm switched off by 'apm=off' kernel option) 1GHz
> PIII 512MB RAM. It seems mobile P6 doesn't provide perf. counter registers
> and so oprofile used rtc. I haven't found yet, how to configure oprofile
> on my machines to measure other data than time spent in functions.
> Karel Gardas firstname.lastname@example.org
> ObjectSecurity Ltd. http://www.objectsecurity.com