Re: what is the default frequency and default event period set in "perf record -TP"

[David Ahern <dsahern@gmail.com>]

On 11/6/13, 4:52 PM, Peipei Wang wrote:
> Hi all/David,
>
> I want to know the frequency in the following command:
>          perf record -e cycles -e cache-misses -e cache-references -TP
> -o abc.data command
>
> I looked up in the perfwiki, and it says the default value is 1000.
> However, when I specify this parameter in the above command,that is,
> "perf record -e cycles -e cache-misses -e cache-references -TP -F 1000
> -o abc.data command", I found a significant difference between the
> file data size.
>
> Using the first command, the size of "abc.data" is about 500MB, but
> the second command could generate the raw data size up to over 10GB.
>
>
> I could not figure out the reason. Is it might because sampling mode
> of cycles is based on frequency while the other two events are based
> on event period?


default frequency was bumped to 4000 about a year ago. Not sure how the 
-F is impacting the cache-xxxx events.

David