Regarding the basic use of perf top command
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
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 <http://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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Hi, The links provided gives description about the perf tool. As i mentioned before, i was interested in the significance of the following: 1. irqs/sec 2. samples 3. pcnt A brief explanation will suffice, as i am also looking into the code of perf top. Thanks Ankur On Wed, Jul 13, 2011 at 9:10 PM, Vipin <vj358@nyu.edu> wrote:
** 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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