Re: [Libguestfs] [PATCH v2 0/7] tests/qemu: Add program for tracing and analyzing boot times.
On Sun, Mar 20, 2016 at 05:28:05PM +0200, Török Edwin wrote:
On 03/20/2016 14:30, Richard W.M. Jones wrote:
> v1 was here:
>
> https://www.redhat.com/archives/libguestfs/2016-March/thread.html#00157
Thanks, this is much better than looking at 'ts -i' output.
BTW I have use 'git am' to apply them to latest git HEAD and try it.
Is this the preferred way, or is there a git branch/repo somewhere that I missed which
would already have these applied?
I've just pushed what I'm working on to my fork of the repo
(https://github.com/rwmjones/libguestfs/commits/master).
Ah, I didn't have sgabios installed, and it complained it
couldn't
find an event (qemu:overhead?).
Right - it's very sensitive to the exact debug output.
Installed it and I got similar results to yours, the largest
overhead is BIOS:
https://gist.github.com/anonymous/37cfb3d4eb3d3a1c86b2
Your qemu overhead is lower. That could be because of:
https://bugzilla.redhat.com/show_bug.cgi?id=1319483
Interestingly your total time is at least double mine. Either your
hardware is slower or there's something else going on.
Thought to try booting a Xen PV domain for comparison, but AFAICT
libguestfs doesn't support LIBGUESTFS_BACKEND=libvirt:xen:///
No, this isn't really going to work. It's a bunch of work to support
completely different hypervisors like Xen, even with libvirt helping.
>, and the other ⅔rds is something else in SeaBIOS.
> Simply removing SGABIOS improves boot times to below 2s, but at a cost
> that we cannot see any messages from SeaBIOS so further measurement
> and therefore improvement becomes impossible. I'm going to try to fix
> SeaBIOS/SGABIOS first. See also:
>
> http://thread.gmane.org/gmane.comp.emulators.qemu/402196
SGABIOS turns out to be caused by something different from what I
thought. See my attempt (not yet working) to fix this:
https://github.com/rwmjones/libguestfs/commit/8ffab2d708e9480741b373c0702...
I haven't looked at SeaBIOS yet. That's the biggest issue.
Nice, this would benefit booting regular VMs too, not just
libguestfs appliances, right?
Yes, this work benefits everyone.
Rich.
--
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
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