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RE: [Xen-devel] Too much VCPUS makes domU high CPU utiliazation


 
> From: kevin.tian@xxxxxxxxx
> To: tinnycloud@xxxxxxxxxxx; xen-devel@xxxxxxxxxxxxxxxxxxx
> CC: george.dunlap@xxxxxxxxxxxxx
> Date: Thu, 19 May 2011 11:39:14 +0800
> Subject: RE: [Xen-devel] Too much VCPUS makes domU high CPU utiliazation
>
> >From: MaoXiaoyun
> >Sent: Thursday, May 19, 2011 12:19 AM
> >HI:
> > 
> >     I have a host with 16 physical CPUS. Dom0 has 4 VCPUS.
> > 
> >    When only start a domU-A(windows 2003 x86 64rc 2) with 16 VCPUS, it starts quickly and eveything is fine.
>
> does same thing happen if you launch B/C/D after A?
>
 
>From test aspects, not really, all domains CPU Util are low.
It looks like this only happen in the process of domain A booting, and result in quite long time to boot.
 
One thing to correct, today even I destory B/C/D, domain A still comsume 800% CPU for quite a long time till now I am writing
this mail.
 
Another strang thing is seems all VCPUS of domainUA, are running only on even number Physicals CPUS(that is 0, 2,4...),
where explains where CPU Util is 800%.  But I don't understand whether this is designed to.
 
Below is the detail shedule log from serial.
Thanks.
 
(XEN) Scheduler: SMP Credit Scheduler (credit)
(XEN) info:
(XEN)   ncpus              = 16
(XEN)   master             = 0
(XEN)   credit             = 4800
(XEN)   credit balance     = 2324
(XEN)   weight             = 512
(XEN)   runq_sort          = 726199
(XEN)   default-weight     = 256
(XEN)   msecs per tick     = 10ms
(XEN)   credits per msec   = 10
(XEN)   ticks per tslice   = 3
(XEN)   ticks per acct     = 3
(XEN)   migration del ay    = 0us
(XEN) idlers: 00000000,00000000,00000000,0000aaaa
(XEN) active vcpus:
(XEN)     1: [0.0] pri=0 flags=0 cpu=0 credit=50 [w=256]
(XEN)     2: [14.8] pri=-1 flags=0 cpu=8 credit=-32 [w=256]
(XEN)     3: [14.5] pri=-1 flags=0 cpu=14 credit=-188 [w=256]
(XEN)     4: [14.10] pri=-1 flags=0 cpu=6 credit=-187 [w=256]
(XEN)     5: [14.14] pri=-1 flags=0 cpu=8 credit=0 [w=256]
(XEN)     6: [14.11] pri=-1 flags=0 cpu=6 credit=0 [w=256]
(XEN)     7: [14.0] pri=-1 flags=0 cpu=4 credit=0 [w=256]
(XEN)     8: [14.15] pri=-1 flags=0 cpu=0 credit=297 [w=256]
(XEN)     9: [14.9] pri=-1 flags=0 cpu=8 credit=300 [w=256]
(XEN)    10: [14.2] pri=-1 flags=0 cpu=6 credit=300 [w=256]
(XEN)    11: [14.6] pri=-1 flags=0 cpu=4 credi t=134 [w=256]
(XEN)    12: [14.3] pri=-1 flags=0 cpu=14 credit=288 [w=256]
(XEN)    13: [14.12] pri=-1 flags=0 cpu=12 credit=-83 [w=256]
(XEN)    14: [14.7] pri=-1 flags=0 cpu=2 credit=65 [w=256]
(XEN)    15: [14.4] pri=-1 flags=0 cpu=10 credit=-145 [w=256]
(XEN) sched_smt_power_savings: disabled
(XEN) NOW=0x00002C6DB4F0EF4B
(XEN) CPU[00]  sort=726199, sibling=00000000,00000000,00000000,00000101, core=00000000,00000000,00000000,00005555
(XEN)   run: [14.13] pri=-1 flags=0 cpu=0 credit=-2 [w=256]
(XEN)     1: [14.15] pri=-1 flags=0 cpu=0 credit=297 [w=256]
(XEN)     2: [14.1] pri=-1 flags=0 cpu=0 credit=-1 [w=256]
(XEN)     3: [32767.0] pri=-64 flags=0 cpu=0
(XEN) CPU[01]  sort=726199, sibling=00000000,00000000,00000000,00000202, core=00000000,00000000,00000000,0000aaaa
(XEN)   run: [32767.1 ] pri=-64 flags=0 cpu=1
(XEN) CPU[02]  sort=726199, sibling=00000000,00000000,00000000,00000404, core=00000000,00000000,00000000,00005555
(XEN)   run: [0.2] pri=0 flags=0 cpu=2 credit=-89 [w=256]
(XEN)     1: [14.7] pri=-1 flags=0 cpu=2 credit=65 [w=256]
(XEN)     2: [32767.2] pri=-64 flags=0 cpu=2
(XEN) CPU[03]  sort=726199, sibling=00000000,00000000,00000000,00000808, core=00000000,00000000,00000000,0000aaaa
(XEN)   run: [32767.3] pri=-64 flags=0 cpu=3
(XEN) CPU[04]  sort=726199, sibling=00000000,00000000,00000000,00001010, core=00000000,00000000,00000000,00005555
(XEN)   run: [14.6] pri=-1 flags=0 cpu=4 credit=134 [w=256]
(XEN)     1: [14.0] pri=-1 flags=0 cpu=4 credit=0 [w=256]
(XEN)     2: [32767.4] pri=-64 flags=0 cpu=4
(XEN) CPU[05]  sort=726199, sibling=00000000,00000000,00000000,00002020, core=00000000,0000 0000,00000000,0000aaaa
(XEN)   run: [32767.5] pri=-64 flags=0 cpu=5
(XEN) CPU[06]  sort=726199, sibling=00000000,00000000,00000000,00004040, core=00000000,00000000,00000000,00005555
(XEN)   run: [14.10] pri=-1 flags=0 cpu=6 credit=-187 [w=256]
(XEN)     1: [14.2] pri=-1 flags=0 cpu=6 credit=300 [w=256]
(XEN)     2: [14.11] pri=-1 flags=0 cpu=6 credit=0 [w=256]
(XEN)     3: [32767.6] pri=-64 flags=0 cpu=6
(XEN) CPU[07]  sort=726199, sibling=00000000,00000000,00000000,00008080, core=00000000,00000000,00000000,0000aaaa
(XEN)   run: [32767.7] pri=-64 flags=0 cpu=7
(XEN) CPU[08]  sort=726199, sibling=00000000,00000000,00000000,00000101, core=00000000,00000000,00000000,00005555
(XEN)   run: [14.8] pri=-1 flags=0 cpu=8 credit=-32 [w=256]
(XEN)     1: [14.14] pri=-1 flags=0 cpu=8 credit=0 [w=256]
(XEN)  &n bsp;  2: [14.9] pri=-1 flags=0 cpu=8 credit=300 [w=256]
(XEN)     3: [32767.8] pri=-64 flags=0 cpu=8
(XEN) CPU[09]  sort=726199, sibling=00000000,00000000,00000000,00000202, core=00000000,00000000,00000000,0000aaaa
(XEN)   run: [32767.9] pri=-64 flags=0 cpu=9
(XEN) CPU[10]  sort=726199, sibling=00000000,00000000,00000000,00000404, core=00000000,00000000,00000000,00005555
(XEN)   run: [14.4] pri=-1 flags=0 cpu=10 credit=-145 [w=256]
(XEN)     1: [32767.10] pri=-64 flags=0 cpu=10
(XEN) CPU[11]  sort=726199, sibling=00000000,00000000,00000000,00000808, core=00000000,00000000,00000000,0000aaaa
(XEN)   run: [32767.11] pri=-64 flags=0 cpu=11
(XEN) CPU[12]  sort=726199, sibling=00000000,00000000,00000000,00001010, core=00000000,00000000,00000000,00005555
(XEN)   run: [14.12] pri=-1 flags=0 cpu=12 credit=-83 [w=256]
(XEN)     1: [32767.12] pri=-64 flags=0 cpu=12
(XEN) CPU[13]  sort=726199, sibling=00000000,00000000,00000000,00002020, core=00000000,00000000,00000000,0000aaaa
(XEN)   run: [32767.13] pri=-64 flags=0 cpu=13
(XEN) CPU[14]  sort=726199, sibling=00000000,00000000,00000000,00004040, core=00000000,00000000,00000000,00005555
(XEN)   run: [14.5] pri=-1 flags=0 cpu=14 credit=-188 [w=256]
(XEN)     1: [14.3] pri=-1 flags=0 cpu=14 credit=288 [w=256]
(XEN)     2: [32767.14] pri=-64 flags=0 cpu=14
(XEN) CPU[15]  sort=726199, sibling=00000000,00000000,00000000,00008080, core=00000000,00000000,00000000,0000aaaa
(XEN)   run: [32767.15] pri=-64 flags=0 cpu=15

> Thanks
> Kevin
>
> > 
> >     But if I first start domU-B, which has 2VCPUS, domU-C 4VCPUS, and domU-D 8 VCPUS,  later I start DomUA again,
> (so we have total 34 VCPUS, plus dom0), it will takes very long time for domU-A to start ,and during the start, its CPU
> utilizaiton is around 800% from xm top, after its start, it response very slow in VNC, ans CPU utiliazation keeps high.
> And right after I destoy other 3 domUs, domUA CPU drops to normal.
> > 
> >   It might relate to CPU schedule, btw, my xen is 4.0.1.
> > 
> >  Any comments?
>  
>      

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