Re: Unresponiveness of 2.4.16

Marcelo Tosatti (marcelo@conectiva.com.br)
Wed, 28 Nov 2001 16:24:42 -0200 (BRST)


On Tue, 27 Nov 2001, 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.
>
> Description:
>
> - Account for locked as well as dirty buffers when deciding
> to throttle writers.

Just one thing: If we have lots of locked buffers due to reads we are
going to may unecessarily block writes, and thats not any good.

But well, I prefer to fix interactivity than to care about that one kind
of workload, so I'm ok with it.

> - Tweak VM to make it work the inactive list harder, before starting
> to evict pages or swap.

I would like to see he interactivity problems get fixed on block layer
side first: Its not a VM issue initially. Actually, the thing is that if
you tweak VM this way you're going to break some workloads.

> - 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.

Sounds fine... I've received quite many success reports already, right ?

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