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Re: xen 3.1 problem (Re: xen 3.1.0 is there)

   On Jun 27, 12:53, Manuel Bouyer wrote:
   > Subject: Re: xen 3.1 problem (Re: xen 3.1.0 is there)
   > > 1st problem: I'm not sure when this started but the latest
   > >   NetBSD DomU runs slower.  Here is a simple benchmark
   > >   result.  The benchmark is to run mkid several times under
   > >   20070624's sys directory and pick one generally good time
   > >   from results.
   > > 
   > > src date                 dom0 time       domu time
   > > 0518 on Xen3.0.4         10.614          9.757
   > > 0624 w/ patch on Xen3.0.4        10.650          16.938  <- slow
   > > 0624 w/ patch on Xen3.1.0        10.625          9.638
   > > 0627 w/ patch on Xen3.0.4        10.640          17.283  <- slow
   > > 0627 w/ patch on Xen3.1.0        10.524          16.817  <- slow
   > > 
   > > I was thinking this is caused since the recent kernel is
   > > optimized for Xen3.1.0, but 0627 kernel runs slower on both.
   > There's not "optimisations" for 3.1.0. The only change was a bug fixe
   > in an ioctl call, which has been there since day 0 of dom0 support
   > but didn't cause problems before (I suspect because before 3.1.0 this
   > interface was always used with a one-element list only. the bug shows up
   > when there's more than one page in the list).

Ok.  Then, I really don't understand why 0624 on Xen3.1.0
was fast and 0627 on Xen3.1.0 is slow.  Like I showed above,
both used 3.1.0.

On the other hand, is it possible to run any benchmark
program on your PC at least using both Dom0 and DomU with
Xen 3.1.0?  I have an interest to see how much slow or the
same on other PC.

I'm wondering like maybe my PC is having more interrupts
than usual and it causes more race condition in locore.S and
make DomU slower...?  Just thought, though.  ;-)

   > > 2nd problem: DomU ask me what is the boot device.  I
   > >   answered xbd0 is root, dump is xbd0b, file system is lfs,
   > >   and init path is /sbin/init.  It works fine after that,
   > >   but I need to let NetBSD DomU knows them each time.
   > I think I know what's the problem. Please try the attached patch

It fixed the problem.  Thanks.

   > > 3rd problem: This is not a real problem.  I just saw the
   > >   throughput of WinXP on NetBSD Dom0 and Xen3.1.0 is similar
   > >   to the WinXP on NetBSD Dom0 and Xen4.0.3.  Just wondering
   > >   how much throughput others are having now.  Mine shows
   > >   4 times slower than standalone WinXP.
   > You should try switching to the pcnet emulated network device. This one
   > gives better results for me on 2003 server (about 3MB/s).

Nice.  It makes WinXP show twice faster throughput.
Although it is still half throughput of native WinXP, it is
nicer than before and much acceptable.  hehe.  Thanks for
the tips.  :-)

-- Kazushi
With a rubber duck, one's never alone.
                -- Douglas Adams, "The Hitchhiker's Guide to the Galaxy"

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