* David Ahern <[email protected]> wrote:
> Record currently wakes up based on watermarks to read events from
> the mmaps and write them out to the file. The result is a file that
> can have large blocks of events per mmap before a finished round
> event is added to the stream. This in turn affects the quantity of
> events that have to be passed through the ordered events queue
> before results can be displayed to the user. For commands like
> perf-script this can lead to long unnecessarily long delays before a
> user gets output. Large systems (e.g, 1024 cpus) further compound
> this effect. I have seen instances where I have to wait 45 minutes
> for perf-script to process a 5GB file before any events are shown.
>
> This patch adds an option to perf-record to allow a user to specify
> the poll timeout in msec. For example using 100 msec timeouts
> similar to perf-top means the mmaps are traversed much more
> frequently leading to a smoother analysis side.
Please tune the default value (perhaps influenced by N_PROC?) so that
users will get sane behavior without having to specify this option!
Thanks,
Ingo
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