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Re: [Qemu-devel] EHCI USB regression in 1.2.0 - ehci_state_fetchqtd() as
From: |
Shawn Starr |
Subject: |
Re: [Qemu-devel] EHCI USB regression in 1.2.0 - ehci_state_fetchqtd() asserting |
Date: |
Mon, 08 Oct 2012 16:18:08 -0400 |
User-agent: |
KMail/4.9.2 (Linux/3.6.0-0.rc7.git0.1.fc18.x86_64; KDE/4.9.2; x86_64; ; ) |
On Monday, October 08, 2012 10:10:49 PM Hans de Goede wrote:
> Hi,
>
> On 10/08/2012 06:11 PM, Johannes Stezenbach wrote:
>
> <mega snip>
>
> > I also wonder if this is not a generic problem
> >
> > for all emulated hw if the driver uses some timeout?
>
> Yes it likely is, because the emulated timer interrupt will
> try to make up for time lost when the vm was not running
> (in either hypervisor or guest mode), while as hw emulation
> code which has been pre-empted for what ever reason my
> simply need some more actual running time before it can
> complete the task as hand, at which point the timeout
> will trigger sooner then the hw emulation can handle the
> task ...
>
> Note that with the EHCI emulation we also can have the
> 2 (guest and hw-emulation time) get out of sync in the
> other way. When we got behind in processing frames
> on the periodic schedule compared to "real-time" we would
> catch up too fast, causing the guest to see large
> jumps in the frindex register, which it does not like.
>
> So all of this really is a precarious balancing act, and
> to get back to the subject of the thread, the latency
> spikes some of the kernels debugging options can cause,
> can upset the balance...
>
Hello folks,
I am using a non-debug kernel (because debug kernels are seriously sluggish).
I may elect to get kernel-3.6.0-3.fc18 or kernel-3.6.1-1.fc18 from koji also
since 3.6 is final now.
Currently using: 3.6.0-0.rc7.git0.1.fc18.x86_64
Thanks,
Shawn.
> Regards,
>
> Hans
- Re: [Qemu-devel] EHCI USB regression in 1.2.0 - ehci_state_fetchqtd() asserting, Shawn Starr, 2012/10/02
- Re: [Qemu-devel] EHCI USB regression in 1.2.0 - ehci_state_fetchqtd() asserting, Hans de Goede, 2012/10/08
- Re: [Qemu-devel] EHCI USB regression in 1.2.0 - ehci_state_fetchqtd() asserting, Johannes Stezenbach, 2012/10/08
- Re: [Qemu-devel] EHCI USB regression in 1.2.0 - ehci_state_fetchqtd() asserting, Hans de Goede, 2012/10/08
- Re: [Qemu-devel] EHCI USB regression in 1.2.0 - ehci_state_fetchqtd() asserting, Johannes Stezenbach, 2012/10/08
- Re: [Qemu-devel] EHCI USB regression in 1.2.0 - ehci_state_fetchqtd() asserting, Hans de Goede, 2012/10/08
- Re: [Qemu-devel] EHCI USB regression in 1.2.0 - ehci_state_fetchqtd() asserting, Johannes Stezenbach, 2012/10/08
- Re: [Qemu-devel] EHCI USB regression in 1.2.0 - ehci_state_fetchqtd() asserting, Hans de Goede, 2012/10/08
- Re: [Qemu-devel] EHCI USB regression in 1.2.0 - ehci_state_fetchqtd() asserting,
Shawn Starr <=
- Re: [Qemu-devel] EHCI USB regression in 1.2.0 - ehci_state_fetchqtd() asserting, Hans de Goede, 2012/10/08
- Re: [Qemu-devel] EHCI USB regression in 1.2.0 - ehci_state_fetchqtd() asserting, Shawn Starr, 2012/10/08