Re: [Qemu-devel] Windows slow boot: contractor wanted

[Avi Kivity]

On 08/17/2012 03:36 PM, Richard Davies wrote:
> Hi Avi,
> 
> Thanks to you and several others for offering help. We will work with Avi at
> first, but are grateful for all the other offers of help. We have a number
> of other qemu-related projects which we'd be interested in getting done, and
> will get in touch with these names (and anyone else who comes forward) to
> see if any are of interest to you.
> 
> 
> This slow boot problem is intermittent and varys in how slow the boots are,
> but I managed to trigger it this morning with medium slow booting (5-10
> minutes) and link to the requested traces below.
> 
> The host in question has 128GB RAM and dual AMD Opteron 6128 (16 cores
> total). It is running kernel 3.5.1 and qemu-kvm 1.1.1.
> 
> In this morning's test, we have 3 guests, all booting Windows with 40GB RAM
> and 8 cores each (we have seen small VMs go slow as I originally said, but
> it is easier to trigger with big VMs):
> 
> pid 15665: qemu-kvm -nodefaults -m 40960 -smp 8 -cpu host,hv_relaxed \
>   -vga cirrus -usbdevice tablet -vnc :99 -monitor stdio -hda test1.raw
> pid 15676: qemu-kvm -nodefaults -m 40960 -smp 8 -cpu host,hv_relaxed \
>   -vga cirrus -usbdevice tablet -vnc :98 -monitor stdio -hda test2.raw
> pid 15653: qemu-kvm -nodefaults -m 40960 -smp 8 -cpu host,hv_relaxed \
>   -vga cirrus -usbdevice tablet -vnc :97 -monitor stdio -hda test3.raw
> 
> We are running with hv_relaxed since this was suggested in the previous
> thread, but we see intermittent slow boots with and without this flag.
> 
> 
> All 3 VMs are booting slowly for most of the attached capture, which I
> started after confirming the slow boots and stopped as soon as the first of
> them (15665) had booted. In terms of visible symptoms, the VMs are showing
> the Windows boot progress bar, which is moving very slowly. In top, the VMs
> are at 400% CPU and their resident state size (RES) memory is slowly
> counting up until it reaches the full VM size, at which point they finish
> booting.
> 
> 
> Here are the trace files:
> 
> http://users.org.uk/slow-win-boot-1/ps.txt (ps auxwwwf as root)
> http://users.org.uk/slow-win-boot-1/top.txt (top with 2 VMs still slow)
> http://users.org.uk/slow-win-boot-1/trace-console.txt (running trace-cmd)
> http://users.org.uk/slow-win-boot-1/trace.dat (the 1.7G trace data file)
> http://users.org.uk/slow-win-boot-1/trace-report.txt (the 4G trace report)
> 
> 
> Please let me know if there is anything else which I can provide?

There are tons of PAUSE exits indicating cpu overcommit (and indeed you
are overcommitted by about 50%).

What host kernel version are you running?

Does this reproduce without overcommit?



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error compiling committee.c: too many arguments to function