Re: [ext3][kernels >= 2.6.20.7 at least] KDE going comatose when FS is under heavy write load (massive starvation)

Mike Galbraith
2007-04-28T07:13:06Z

On Sat, 2007-04-28 at 00:01 -0700, Andrew Morton wrote:
> On Sat, 28 Apr 2007 08:32:32 +0200 Mike Galbraith <efault@gmx.de> wrote:
>
> > On Sat, 2007-04-28 at 06:25 +0200, Mike Galbraith wrote:

> > As promised, I tested with a kernel that I know for fact that I have
> > tested heavy IO on previously, and behavior was identically horrid, so
> > it's not something new that snuck in ~recently, my disk just got a _lot_
> > fuller in the meantime (12k mp3s munch a lot).
>
> Just to clarify here - you're saying that some older kernel is as sucky as
> 2.6.21, and that (presumably) dropping the dirty ratios makes things a bit
> better on the old kernel as well?

I didn't drop dirty ratios, only verified that behavior was just as
horrible as 2.6.21.

> Actually, I'm surprised that data=writeback didn't help much. If the
> present theories are correct it should have helped quite a lot, because in
> data=writeback mode fsync(small-file) will not cause
> fdatasync(everything-else).

data=writeback did help quite noticeably, just not enough.

-Mike