Re: Regarding the basic use of perf top command

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Hi,

I think this should suffice
https://perf.wiki.kernel.org/index.php/Tutorial#Live_analysis_with_perf_top

Rest of the information is archived here
http://lxr.linux.no/linux+v2.6.39/tools/perf/Documentation/

The value of 1000Hz means the frequency at which the system's timer is programmed to interrupt the kernel. It is a kernel configurable option.

Thanks
Vipin
On 07/13/2011 10:59 AM, ankur dwivedi wrote:
Hi,

My question is regarding the basic use of perf top command in linux.

The following is the snap shot of running a "perf top -e cache-misses" command from console:

----------------------------------------------------------------------------------------------------------------------------------------------------------------------
   PerfTop:      76 irqs/sec  kernel:14.5%  exact:  0.0% [1000Hz cache-misses],  (all, 12 CPUs)
----------------------------------------------------------------------------------------------------------------------------------------------------------------------

             samples  pcnt function                DSO
             _______ _____ _______________________ ____________________________________

               48.00 36.9% get_page_from_freelist  [kernel.kallsyms]                  
               12.00  9.2% JS_CallTracer           /usr/lib/xulrunner-1.9.2/libmozjs.so
               12.00  9.2% JS_TraceChildren        /usr/lib/xulrunner-1.9.2/libmozjs.so
                8.00  6.2% dso__find_symbol        /usr/bin/perf                      
                7.00  5.4% native_flush_tlb_single [kernel.kallsyms]                  
                6.00  4.6% _int_malloc             /lib/libc-2.12.90.so               


What i want to know is the significance of different parameters here which are the following:
1. irqs/sec
2. samples
3. pcnt

It also shows a value of 1000Hz. what is the meaning of that.

I searched regarding these in the internet, but was unable to find a good explanation

Thanks
Ankur


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