Re: 2.6.24 says "serial8250: too much work for irq4" a lot.

From: Rob Landley <rob@landley.net>
To: "H. Peter Anvin" <hpa@zytor.com>
Cc: Ingo Molnar <mingo@elte.hu>, linux-kernel@vger.kernel.org
Subject: Re: 2.6.24 says "serial8250: too much work for irq4" a lot.
Date: Thu, 7 Feb 2008 14:13:44 -0600	[thread overview]
Message-ID: <200802071413.45085.rob@landley.net> (raw)
In-Reply-To: <47AB41C8.3010001@zytor.com>

On Thursday 07 February 2008 11:37:12 H. Peter Anvin wrote:
> > actually, the way i solved it for qemu+KVM+paravirt was to just turn off
> > this rather silly check in the serial driver if inside a paravirt guest.
> > When we are emulated then the serial 'hardware' is totally reliable and
> > we should just trust it. That way i never dropped a single bit of kernel
> > log output again.
>
> Yes, but keying that on paravirt is silly in the extreme.  After all,
> there is no need for this to be paravirtualized.
>
> 	-hpa

Specifically, qemu isn't paravirtualized, it's fully virtualized.  The same 
kernel can run on real hardware just fine.  (Sort of the point of the 
project...)

I can yank the warning for the kernels I build (or set PASS_LIMIT to 9999999), 
but I'd rather not carry any more patches than I can avoid...

Rob
-- 
"One of my most productive days was throwing away 1000 lines of code."
  - Ken Thompson.