[Qemu-devel] kernel 2.6 losing too many ticks

[Qemu-devel] kernel 2.6 losing too many ticks

[zitu]

Hi,

Host=XP
Guest=linux lfs 2.6.5 (from a bootlfs cd iso)

When I try to boot under qemu 0.6 and above, it takes forever.
This does not happen with 2.4 kernels. Anyway to fix this else
than recompiling the 2.6 kernel ?

On a side-line, does qemu-fast exist for win32 ?

Rgds,
Zitu

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Re: [Qemu-devel] kernel 2.6 losing too many ticks

[bennet]

A speedup can  be made by passing clock=pit to the kernel parameters (at 
lilo  prompt: linux clock=pit)
But there's still a problem with some timers : sleep 1 sleeps for about 
10 seconds !
I can't find why, and don't know how to get more information to solve 
the problem.

Hope it helps

zitu a écrit :

>Hi,
>
>Host=XP
>Guest=linux lfs 2.6.5 (from a bootlfs cd iso)
>
>When I try to boot under qemu 0.6 and above, it takes forever.
>This does not happen with 2.4 kernels. Anyway to fix this else
>than recompiling the 2.6 kernel ?
>
>On a side-line, does qemu-fast exist for win32 ?
>
>Rgds,
>Zitu
>
>--
>
>
>
>_______________________________________________
>Qemu-devel mailing list
>Qemu-devel@nongnu.org
>http://lists.nongnu.org/mailman/listinfo/qemu-devel
>
>  
>

Re: [Qemu-devel] kernel 2.6 losing too many ticks

[Juergen Lock]

On Fri, Oct 01, 2004 at 07:43:20PM +0000, bennet wrote:
> A speedup can  be made by passing clock=pit to the kernel parameters (at 
> lilo  prompt: linux clock=pit)
> But there's still a problem with some timers : sleep 1 sleeps for about 
> 10 seconds !
> I can't find why, and don't know how to get more information to solve 
> the problem.

This happens when the host's hz is < than the guest's: linux 2.4 kernels
have a default of 100 and 2.6 kernels of 1000 -> factor 10, which you see
with `sleep 1'.  Also, qemu has an internal limit of 1000 (or 1024?),
so if your guest's hz is > than that it'll still be slow even if the
hosts's hz is as fast or faster.  (Maybe this should be made configurable?
some ppl use e.g. hz 5000 to increase gig ethernet performance, like
the FreeSBIE kernel...)

 HTH,
	Juergen

Re: [Qemu-devel] kernel 2.6 losing too many ticks

[zitu]

Quoting bennet:
> A speedup can  be made by passing clock=pit to the kernel parameters (at
> lilo  prompt: linux clock=pit)
> But there's still a problem with some timers : sleep 1 sleeps for about
> 10 seconds !
> I can't find why, and don't know how to get more information to solve
> the problem.
>
> Hope it helps
>

clock=pit worked like a charm.
Thx

Zitu
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