Re: ext3_ordered_writepage() questions

["Stephen C. Tweedie" <sct@redhat.com>]

Hi,

On Fri, 2006-03-17 at 15:23 -0800, Mingming Cao wrote:

> > > There is one other perspective to be aware of, though: the current
> > > behaviour means that by default ext3 generally starts flushing pending
> > > writeback data within 5 seconds of a write.  Without that, we may end up
> > > accumulating a lot more dirty data in memory, shifting the task of write
> > > throttling from the filesystem to the VM.  

> Current data=writeback mode already behaves like this, so the VM
> subsystem should be tested for a certain extent, isn't?

Yes, but there are repeated reports that for many workloads,
data=writeback is actually slower than data=ordered.  So there are
probably some interactions like this which may be hurting us already.

--Stephen


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/