Re: 2.4.9-ac1 RAID-5 resync causes PPP connection to be unusable

Martin Josefsson
2001-08-31T15:44:54Z

On Fri, 31 Aug 2001, Andreas Dilger wrote:

> On Aug 30, 2001 21:23 -0700, Kevin P. Fleming wrote:
> > OK, I see that now... and it looks like the risks associated with setting
> > the unmaskirq flags on my drives (none of the four drives have it set now)
> > are too great to be worth playing with it. I'll just not use my PPP
> > connection during these particularly heavy disk activity moments. Thanks for
> > the quick response.
>
> There was a kernel patch (or possibly a user-space tool) which allowed
> one to change the "priority" of IRQs and their handlers. This was back
> in the 1.2 or 2.0 days, when _any_ disk or other interrupt activity might
> be enough to cause problems for serial connections (especially if you
> only had a 16450 UART (1 byte buffer) instead of a 16550 (16 byte buffer).
> You could make your serial interrupt (handler) take priority over disk
> interrupts.
>
> Maybe Ted Ts'o or other long-time Linux folks will know what was actually
> called, and whether it is still applicable to modern hardware/kernel.

It was called irqtune, http://www.best.com/~cae/irqtune/
But I don't know if it still works with newer hardware/kernel

/Martin