Re: [PATCH v2] mm: implement write-behind policy for sequential file writes

[Linus Torvalds]

On Fri, Sep 20, 2019 at 4:05 PM Linus Torvalds
<torvalds@xxxxxxxxxxxxxxxxxxxx> wrote:
>
>
> Now, I hear you say "those are so small these days that it doesn't
> matter". And maybe you're right. But particularly for slow media,
> triggering good streaming write behavior has been a problem in the
> past.

Which reminds me: the writebehind trigger should likely be tied to the
estimate of the bdi write speed.

We _do_ have that avg_write_bandwidth thing in the bdi_writeback
structure, it sounds like a potentially good idea to try to use that
to estimate when to do writebehind.

No?

            Linus