Re: Linux 2.6.29

Bron Gondwana
2009-03-25T23:46:22Z

On Wed, Mar 25, 2009 at 04:23:08PM -0700, Linus Torvalds wrote:
>
>
> On Wed, 25 Mar 2009, Theodore Tso wrote:
> > >
> > > The problem being that unlike the ratio, there's no sane default value
> > > that you can at least argue is not _entirely_ pointless.
> >
> > Well, if the maximum time that someone wants to wait for an fsync() to
> > return is one second, and the RAID array can write 100MB/sec
>
> How are you going to tell the kernel that the RAID array can write
> 100MB/s?
>
> The kernel has no idea.

Not at boot up, but after it's been using the RAID array for a little
while it could...

Bron (... imagining a tunable "max_fsync_wait_target_centisecs = 100"
which caused the kernel to notice how long flushes were taking
and tune its buffer sizes to be approximately right over time )