[Qemu-devel] FC2 guest is working slower than RH9 on FC2 host

[Qemu-devel] FC2 guest is working slower than RH9 on FC2 host

[Mulyadi Santosa]

Hello everybody

Yesterday I tried to install Fedora Core 2 guest using qemu 0.7.1 (no 
kqemu) on top of FC 2 host. Both guest and host are running 2.6.5-1.358 
(the default kernel of FC2). I experienced slower boot speed and slower 
keyboard typing (the delay between a key a pressed and the actual 
character is showed). Couple weeks ago I installed RH9 as guest also on 
top of FC2 host but the speed is better.

Is it because the guest kernel (FC2) using HZ=1000 so qemu has problem 
on syncing the clock? or are there any technical explanations on why it 
happens?

My PC spec:
AMD Athlon XP 1800+
RAM 256  MB DDR
Hard disk 80 GB EIDE
GeForce 2 MX 440 (X display is using nvidia driver)

regards

Mulyadi

Re: [Qemu-devel] FC2 guest is working slower than RH9 on FC2 host

[Ozan Türkyılmaz]

On 31/07/05, Mulyadi Santosa <a_mulyadi@softhome.net> wrote:
> Hello everybody
> 
> Yesterday I tried to install Fedora Core 2 guest using qemu 0.7.1 (no
> kqemu) on top of FC 2 host. Both guest and host are running 2.6.5-1.358
> (the default kernel of FC2). I experienced slower boot speed and slower
> keyboard typing (the delay between a key a pressed and the actual
> character is showed). Couple weeks ago I installed RH9 as guest also on
> top of FC2 host but the speed is better.
> 
> Is it because the guest kernel (FC2) using HZ=1000 so qemu has problem
> on syncing the clock? or are there any technical explanations on why it
> happens?
> 
what was the ram you told qemu ?
(-m )

> My PC spec:
> AMD Athlon XP 1800+
> RAM 256  MB DDR
> Hard disk 80 GB EIDE
> GeForce 2 MX 440 (X display is using nvidia driver)
> 
> regards
> 
> Mulyadi
> 
> 
> 
> _______________________________________________
> Qemu-devel mailing list
> Qemu-devel@nongnu.org
> http://lists.nongnu.org/mailman/listinfo/qemu-devel
> 


-- 
Ozan

Re: [Qemu-devel] FC2 guest is working slower than RH9 on FC2 host

[Hetz Ben Hamo]

Add: clock=pit
to the fedora core GRUB kernel boot parameters .

Hetz

On 7/31/05, Mulyadi Santosa <a_mulyadi@softhome.net> wrote:
> Hello everybody
> 
> Yesterday I tried to install Fedora Core 2 guest using qemu 0.7.1 (no
> kqemu) on top of FC 2 host. Both guest and host are running 2.6.5-1.358
> (the default kernel of FC2). I experienced slower boot speed and slower
> keyboard typing (the delay between a key a pressed and the actual
> character is showed). Couple weeks ago I installed RH9 as guest also on
> top of FC2 host but the speed is better.
> 
> Is it because the guest kernel (FC2) using HZ=1000 so qemu has problem
> on syncing the clock? or are there any technical explanations on why it
> happens?
> 
> My PC spec:
> AMD Athlon XP 1800+
> RAM 256  MB DDR
> Hard disk 80 GB EIDE
> GeForce 2 MX 440 (X display is using nvidia driver)
> 
> regards
> 
> Mulyadi
> 
> 
> 
> _______________________________________________
> Qemu-devel mailing list
> Qemu-devel@nongnu.org
> http://lists.nongnu.org/mailman/listinfo/qemu-devel
>

Re: [Qemu-devel] FC2 guest is working slower than RH9 on FC2 host

[Mulyadi Santosa]

Hello Hetz, Ozan...

> Add: clock=pit
> to the fedora core GRUB kernel boot parameters .

I have tried it....still feel slower than RH 9....I've tried 
HPET=disable too with no luck. I'll try to investigate this issue 
deeper but still welcome everyone's ideas

To Ozan: i use -m 256..... do I need more?

regards

Mulyadi

Re: Re: [Qemu-devel] FC2 guest is working slower than RH9 on FC2 host

[Mulyadi Santosa]

On Tuesday 02 August 2005 13:26, Mulyadi Santosa wrote:
> I have tried it....still feel slower than RH 9....I've tried
> HPET=disable too with no luck. I'll try to investigate this issue
> deeper but still welcome everyone's ideas

Following up my own earlier posting today, I have discovered the reason 
why FC2 boots and runs so slow. FC2 default kernel is incorporating non 
standard 4G/4G VM split, enabled by this .config parameter:
	CONFIG_X86_4G_VM_LAYOUT=y

It has been warned already by Linux kernel's help related to the above 
parameter, that it triggers more TLB flushes and more overhead when 
doing copy_from/to_user. Qemu-doc.html also warns more or less same 
thing about FC2 default kernel

So far, the best I can tell is, use standard 2.6 kernel on both host and 
guest to avoid this kind of non standard VM split. clock=pit also helps 
speeding up execution a bit

regards

Mulyadi