Re: [RFC v3 09/13] vfs: add one wq to update map info periodically

From: Zheng Liu
Date: Wed Oct 17 2012 - 22:14:33 EST


On Wed, Oct 17, 2012 at 02:34:15PM +0800, Zhi Yong Wu wrote:
> >> diff --git a/fs/hot_tracking.h b/fs/hot_tracking.h
> >> index d19e64a..7a79a6d 100644
> >> --- a/fs/hot_tracking.h
> >> +++ b/fs/hot_tracking.h
> >> @@ -36,6 +36,9 @@
> >> */
> >> #define TIME_TO_KICK 400
> >>
> >> +/* set how often to update temperatures (seconds) */
> >> +#define HEAT_UPDATE_DELAY 400
> >
> > FWIW, 400 seconds is an unusual time period. It's expected that
> > periodic work might take place at intervals of 5 minutes, 10
> > minutes, etc, not 6m40s. It's much easier to predict and understand
> > behaviour if it's at a interval of whole units like minutes,
> > especially when looking at timestamped event traces. Hence 300s (5
> > minutes) makes a lot more sense as a period for updates...
> got it. thanks.

Hi Zhi Yong,

IMHO we'd better to make this value parameterized, and then the user
can adjust this value dynamically.

Regards,
Zheng
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