Re: A unresponsive file system can hang all I/O in the system on linux-2.6.23-rc6 (dirty_thresh problem?)

Trond Myklebust
2007-09-28T17:01:18Z

On Thu, 2007-09-27 at 23:50 -0700, Andrew Morton wrote:

> Actually we perhaps could address this at the VFS level in another way.
> Processes which are writing to the dead NFS server will eventually block in
> balance_dirty_pages() once they've exceeded the memory limits and will
> remain blocked until the server wakes up - that's the behaviour we want.
>
> What we _don't_ want to happen is for other processes which are writing to
> other, non-dead devices to get collaterally blocked. We have patches which
> might fix that queued for 2.6.24. Peter?

Do these patches also cause the memory reclaimers to steer clear of
devices that are congested (and stop waiting on a congested device if
they see that it remains congested for a long period of time)? Most of
the collateral blocking I see tends to happen in memory allocation...

Cheers
Trond