Re: checkpointer continuous flushing - V18

On 2016-02-19 22:46:44 +0100, Fabien COELHO wrote:
>
> Hello Andres,
>
> >Here's the next two (the most important) patches of the series:
> >0001: Allow to trigger kernel writeback after a configurable number of writes.
> >0002: Checkpoint sorting and balancing.
>
> I will look into these two in depth.
>
> Note that I would have ordered them in reverse because sorting is nearly
> always very beneficial, and "writeback" (formely called flushing) is then
> nearly always very beneficial on sorted buffers.

I had it that way earlier. I actually saw pretty large regressions from
sorting alone in some cases as well, apparently because the kernel
submits much larger IOs to disk; although that probably only shows on
SSDs. This way the modifications imo look a trifle better ;). I'm
intending to commit both at the same time, keep them separate only
because they're easier to ynderstand separately.

Andres