Re: regression: 100% io-wait with 2.6.24-rcX

Peter Zijlstra
2008-01-14T11:41:35Z

On Mon, 2008-01-14 at 12:30 +0100, Joerg Platte wrote:
> Am Montag, 14. Januar 2008 schrieb Fengguang Wu:
>
> > Joerg, this patch fixed the bug for me :-)
>
> Fengguang, congratulations, I can confirm that your patch fixed the bug! With
> previous kernels the bug showed up after each reboot. Now, when booting the
> patched kernel everything is fine and there is no longer any suspicious
> iowait!
>
> Do you have an idea why this problem appeared in 2.6.24? Did somebody change
> the ext2 code or is it related to the changes in the scheduler?

It was Fengguang who changed the inode writeback code, and I guess the
new and improved code was less able do deal with these funny corner
cases. But he has been very good in tracking them down and solving them,
kudos to him for that work!