Re: Unresponiveness of 2.4.16

[Mike Fedyk <mfedyk@matchmail.com>]

On Tue, Nov 27, 2001 at 12:57:19PM -0800, Andrew Morton wrote:
> Mike Fedyk wrote:
> > 
> > >   I'll send you a patch which makes the VM less inclined to page things
> > >   out in the presence of heavy writes, and which decreases read
> > >   latencies.
> > >
> > Is this patch posted anywhere?
> 
> I sent it yesterday, in this thread.  Here it is again.
>

Yep, saw it.  I didn't realize (didn't read patch) that it modified the VM
swapping. 

> Description:
> 
> - Account for locked as well as dirty buffers when deciding
>   to throttle writers.
> 
> - Tweak VM to make it work the inactive list harder, before starting
>   to evict pages or swap.
> 
> - Change the elevator so that once a request's latency has
>   expired, we can still perform merges in front of that
>   request.  But we no longer will insert new requests in
>   front of that request.  
> 
> - Modify elevator so that new read requests do not have
>   more than N write requests placed in front of them, where
>   N is tunable per-device with `elvtune -b'.
> 
>   Theoretically, the last change needs significant alterations
>   to the readhead code.  But a rewrite of readhead made negligible
>   difference (I wasn't able to trigger the failure scenario).
>   Still crunching on this.
>

Sounds great.

I'll test it out.

MF