Re: [PATCH 2/5] writeback: dirty position control

Wu Fengguang
2011-08-16T08:59:37Z

> > bdi_position_ratio() provides a scale factor to bdi->dirty_ratelimit, so
> > that the resulted task rate limit can drive the dirty pages back to the
> > global/bdi setpoints.
> >
>
> IMHO, "position_ratio" is not necessarily very intutive. Can there be
> a better name? Based on your slides, it is scaling factor applied to
> task rate limit depending on how well we are doing in terms of meeting
> our goal of dirty limit. Will "dirty_rate_scale_factor" or something like
> that make sense and be little more intutive?

Yeah position_ratio is some scale factor to the dirty rate, and I
added a comment for that. On the other hand position_ratio does
reflect the underlying "position control of dirty pages" logic. So
over time it should be reasonably understandable in the other way :)

Thanks,
Fengguang