Re: [PATCH v2] perf stat: enable 1ms interval for printing event counters values

From: Jiri Olsa
Date: Wed Apr 04 2018 - 03:05:25 EST


On Tue, Apr 03, 2018 at 09:18:33PM +0300, Alexey Budankov wrote:
>
> Currently print count interval for performance counters values is
> limited by 10ms so reading the values at frequencies higher than 100Hz
> is restricted by the tool.
>
> This change makes perf stat -I possible on frequencies up to 1KHz and,
> to some extent, makes perf stat -I to be on-par with perf record
> sampling profiling.
>
> When running perf stat -I for monitoring e.g. PCIe uncore counters and
> at the same time profiling some I/O workload by perf record e.g. for
> cpu-cycles and context switches, it is then possible to observe
> consolidated CPU/OS/IO(Uncore) performance picture for that workload.
>
> Tool overhead warning printed when specifying -v option can be missed
> due to screen scrolling in case you have output to the console
> so message is moved into help available by running perf stat -h.
>
> Signed-off-by: Alexey Budankov <alexey.budankov@xxxxxxxxxxxxxxx>
> ---
>
> Changes in v2:
> - updated minimum value to 1ms at perf-stat.txt manual

Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx>

thanks,
jirka