Re: Linux-2.4.1-pre11 / ll_rw_b watermark metric?

[Jens Axboe]

On Mon, Jan 29 2001, Petr Vandrovec wrote:
> On 29 Jan 01 at 4:43, Dieter Nützel wrote:
> > I have pre11 running with Andrea's suggested fix.
> >
> >         high_queued_sectors = total_ram / 3;
> >         low_queued_sectors = high_queued_sectors / 2;
> >         if (low_queued_sectors < 0)
> >                 low_queued_sectors = total_ram / 2;
> >
> 
> I have one question: How it can happen that low_queued_sectors
> is less than zero with this changed logic? (And if it get triggered,
> low_queued_sectors will be greater than high_queued_sectors - which
> is not what we want...)

This wasn't my change, but you're right it's wrong.

> But it is certainly better than 2.4.0-pre8 approach, as
> with 200MB of memory (exactly 192MB left unused) you can end up with
> low_queued_sectors == 0... And it does not give you optimal behavior.

Same here, definitely not right either. Dunno how I missed that.

-- 
Jens Axboe