* *insane* amount of host_state_reloads for openbsd guest in 0.14
@ 2011-03-11 12:02 Michael Tokarev
2011-03-14 10:00 ` Daniel Bareiro
2011-03-16 19:48 ` Marcelo Tosatti
0 siblings, 2 replies; 5+ messages in thread
From: Michael Tokarev @ 2011-03-11 12:02 UTC (permalink / raw)
To: KVM list
I tried Openbsd 4.8 in kvm today and immediately noticed
that it is running _very_ slow, boot takes several minutes
to complete to the "login:" prompt. After investigating
I found that kvm does really insane amount of host_state_reloads.
Here are typical kvm_stats:
During bootup while checking/mounting filesystems etc:
host_state_reload 13782074 671689
exits 24071297 45751
insn_emulation 21707073 45353
io_exits 6900215 288
mmio_exits 20057 226
irq_injections 6533 223
pf_fixed 9801 176
mmu_pte_write 17781 111
irq_exits 6490 20
fpu_reload 133 1
halt_exits 422 0
mmu_cache_miss 333 0
halt_wakeup 30 0
mmu_shadow_zapped 358 0
remote_tlb_flush 3 0
signal_exits 1 0
After booting, idle guest sitting at login: prompt:
host_state_reload 28675531 44171
exits 25184108 3379
insn_emulation 22784490 3266
irq_injections 54139 200
mmio_exits 52748 122
mmu_pte_write 41584 100
halt_exits 22731 99
irq_exits 9220 12
io_exits 6912620 9
fpu_reload 765 1
pf_fixed 12419 0
mmu_shadow_zapped 358 0
mmu_cache_miss 339 0
halt_wakeup 38 0
remote_tlb_flush 3 0
signal_exits 1 0
So I played with various options for a bit and found that:
o 0.14 -no-kvm-irqchip gets rid of host_state_reloads, making
them to be the same (+/-100) as insn_emulations, and speeds
up guest significantly (and lowers CPU usage on host during
guest idle time).
o 0.14 -no-kvm makes the guest *faster* than w/o any additional
options, reducing boot time for about 50% (but increasing host
CPU usage to maximum)
o 0.12 without any options is the fastest, and it keeps number
of reloads to be within 3k/sec range during all time. here's
typical kvm_stats of idle guest with 0.12:
kvm 0.12 and idle guest:
exits 25975600 3329
insn_emulation 23555272 3229
host_state_reload 1898575 3117
irq_injections 13125 200
mmio_exits 26603 122
mmu_pte_write 61515 100
halt_exits 5173 100
irq_exits 6927 1
fpu_reload 499 1
io_exits 7058999 1
pf_fixed 11902 0
mmu_shadow_zapped 634 0
mmu_cache_miss 558 0
halt_wakeup 166 0
remote_tlb_flush 2 0
signal_exits 1 0
Again, running on the same AthlonII machine with 2.6.37 host
kernel, freshly installed openbsd 4.3 32bit guest (with all
defaults).
FreeBSD does not show this behavour.
What it can be?
Thanks!
/mjt
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: *insane* amount of host_state_reloads for openbsd guest in 0.14
2011-03-11 12:02 *insane* amount of host_state_reloads for openbsd guest in 0.14 Michael Tokarev
@ 2011-03-14 10:00 ` Daniel Bareiro
2011-03-16 19:48 ` Marcelo Tosatti
1 sibling, 0 replies; 5+ messages in thread
From: Daniel Bareiro @ 2011-03-14 10:00 UTC (permalink / raw)
To: KVM list
[-- Attachment #1: Type: text/plain, Size: 849 bytes --]
Hi, Michael.
On Friday, 11 March 2011 15:02:33 +0300,
Michael Tokarev wrote:
> I tried Openbsd 4.8 in kvm today and immediately noticed
> that it is running _very_ slow, boot takes several minutes
> to complete to the "login:" prompt. After investigating
> I found that kvm does really insane amount of host_state_reloads.
> Here are typical kvm_stats:
>
> [...]
Some time ago I commented [1] on the list a substance difference observed in
the network transfer rate in a virtual machine with OpenBSD 4.8
regarding virtual machines with Debian GNU/Linux. Could this be related
to the same problem you mentioned?
Regards,
Daniel
[1] http://thread.gmane.org/gmane.comp.emulators.kvm.devel/65876
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^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: *insane* amount of host_state_reloads for openbsd guest in 0.14
2011-03-11 12:02 *insane* amount of host_state_reloads for openbsd guest in 0.14 Michael Tokarev
2011-03-14 10:00 ` Daniel Bareiro
@ 2011-03-16 19:48 ` Marcelo Tosatti
2011-03-16 19:55 ` Michael Tokarev
1 sibling, 1 reply; 5+ messages in thread
From: Marcelo Tosatti @ 2011-03-16 19:48 UTC (permalink / raw)
To: Michael Tokarev; +Cc: KVM list
On Fri, Mar 11, 2011 at 03:02:33PM +0300, Michael Tokarev wrote:
> I tried Openbsd 4.8 in kvm today and immediately noticed
> that it is running _very_ slow, boot takes several minutes
> to complete to the "login:" prompt. After investigating
> I found that kvm does really insane amount of host_state_reloads.
> Here are typical kvm_stats:
>
> During bootup while checking/mounting filesystems etc:
>
> host_state_reload 13782074 671689
> exits 24071297 45751
> insn_emulation 21707073 45353
> io_exits 6900215 288
> mmio_exits 20057 226
> irq_injections 6533 223
> pf_fixed 9801 176
> mmu_pte_write 17781 111
> irq_exits 6490 20
> fpu_reload 133 1
> halt_exits 422 0
> mmu_cache_miss 333 0
> halt_wakeup 30 0
> mmu_shadow_zapped 358 0
> remote_tlb_flush 3 0
> signal_exits 1 0
>
>
> After booting, idle guest sitting at login: prompt:
>
> host_state_reload 28675531 44171
> exits 25184108 3379
> insn_emulation 22784490 3266
> irq_injections 54139 200
> mmio_exits 52748 122
> mmu_pte_write 41584 100
> halt_exits 22731 99
> irq_exits 9220 12
> io_exits 6912620 9
> fpu_reload 765 1
> pf_fixed 12419 0
> mmu_shadow_zapped 358 0
> mmu_cache_miss 339 0
> halt_wakeup 38 0
> remote_tlb_flush 3 0
> signal_exits 1 0
>
>
> So I played with various options for a bit and found that:
>
> o 0.14 -no-kvm-irqchip gets rid of host_state_reloads, making
> them to be the same (+/-100) as insn_emulations, and speeds
> up guest significantly (and lowers CPU usage on host during
> guest idle time).
>
> o 0.14 -no-kvm makes the guest *faster* than w/o any additional
> options, reducing boot time for about 50% (but increasing host
> CPU usage to maximum)
>
> o 0.12 without any options is the fastest, and it keeps number
> of reloads to be within 3k/sec range during all time. here's
> typical kvm_stats of idle guest with 0.12:
>
> kvm 0.12 and idle guest:
>
> exits 25975600 3329
> insn_emulation 23555272 3229
> host_state_reload 1898575 3117
> irq_injections 13125 200
> mmio_exits 26603 122
> mmu_pte_write 61515 100
> halt_exits 5173 100
> irq_exits 6927 1
> fpu_reload 499 1
> io_exits 7058999 1
> pf_fixed 11902 0
> mmu_shadow_zapped 634 0
> mmu_cache_miss 558 0
> halt_wakeup 166 0
> remote_tlb_flush 2 0
> signal_exits 1 0
>
>
> Again, running on the same AthlonII machine with 2.6.37 host
> kernel, freshly installed openbsd 4.3 32bit guest (with all
> defaults).
>
> FreeBSD does not show this behavour.
>
> What it can be?
Perhaps OpenBSD is accessing the HPET frequently, which is emulated
in userspace. Try disabling it with "-no-hpet".
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: *insane* amount of host_state_reloads for openbsd guest in 0.14
2011-03-16 19:48 ` Marcelo Tosatti
@ 2011-03-16 19:55 ` Michael Tokarev
2011-03-17 7:24 ` Gleb Natapov
0 siblings, 1 reply; 5+ messages in thread
From: Michael Tokarev @ 2011-03-16 19:55 UTC (permalink / raw)
To: Marcelo Tosatti; +Cc: KVM list
16.03.2011 22:48, Marcelo Tosatti wrote:
> On Fri, Mar 11, 2011 at 03:02:33PM +0300, Michael Tokarev wrote:
>> I tried Openbsd 4.8 in kvm today and immediately noticed
>> that it is running _very_ slow, boot takes several minutes
>> to complete to the "login:" prompt. After investigating
>> I found that kvm does really insane amount of host_state_reloads.
>> Here are typical kvm_stats:
>>
>> During bootup while checking/mounting filesystems etc:
>>
>> host_state_reload 13782074 671689
>> exits 24071297 45751
>> insn_emulation 21707073 45353
>> io_exits 6900215 288
[]
>> After booting, idle guest sitting at login: prompt:
>>
>> host_state_reload 28675531 44171
>> exits 25184108 3379
>> insn_emulation 22784490 3266
>> irq_injections 54139 200
[]
>> So I played with various options for a bit and found that:
>>
>> o 0.14 -no-kvm-irqchip gets rid of host_state_reloads, making
>> them to be the same (+/-100) as insn_emulations, and speeds
>> up guest significantly (and lowers CPU usage on host during
>> guest idle time).
>>
>> o 0.14 -no-kvm makes the guest *faster* than w/o any additional
>> options, reducing boot time for about 50% (but increasing host
>> CPU usage to maximum)
>>
>> o 0.12 without any options is the fastest, and it keeps number
>> of reloads to be within 3k/sec range during all time. here's
>> typical kvm_stats of idle guest with 0.12:
>>
> Perhaps OpenBSD is accessing the HPET frequently, which is emulated
> in userspace. Try disabling it with "-no-hpet".
-no-hpet makes no visible difference, exactly the same thing as above:
host_state_reload 21310655 43968
exits 25007599 3573
insn_emulation 22635201 3469
Thanks!
/mjt
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: *insane* amount of host_state_reloads for openbsd guest in 0.14
2011-03-16 19:55 ` Michael Tokarev
@ 2011-03-17 7:24 ` Gleb Natapov
0 siblings, 0 replies; 5+ messages in thread
From: Gleb Natapov @ 2011-03-17 7:24 UTC (permalink / raw)
To: Michael Tokarev; +Cc: Marcelo Tosatti, KVM list
On Wed, Mar 16, 2011 at 10:55:02PM +0300, Michael Tokarev wrote:
> 16.03.2011 22:48, Marcelo Tosatti wrote:
> > On Fri, Mar 11, 2011 at 03:02:33PM +0300, Michael Tokarev wrote:
> >> I tried Openbsd 4.8 in kvm today and immediately noticed
> >> that it is running _very_ slow, boot takes several minutes
> >> to complete to the "login:" prompt. After investigating
> >> I found that kvm does really insane amount of host_state_reloads.
> >> Here are typical kvm_stats:
> >>
> >> During bootup while checking/mounting filesystems etc:
> >>
> >> host_state_reload 13782074 671689
> >> exits 24071297 45751
> >> insn_emulation 21707073 45353
> >> io_exits 6900215 288
> []
> >> After booting, idle guest sitting at login: prompt:
> >>
> >> host_state_reload 28675531 44171
> >> exits 25184108 3379
> >> insn_emulation 22784490 3266
> >> irq_injections 54139 200
> []
> >> So I played with various options for a bit and found that:
> >>
> >> o 0.14 -no-kvm-irqchip gets rid of host_state_reloads, making
> >> them to be the same (+/-100) as insn_emulations, and speeds
> >> up guest significantly (and lowers CPU usage on host during
> >> guest idle time).
> >>
> >> o 0.14 -no-kvm makes the guest *faster* than w/o any additional
> >> options, reducing boot time for about 50% (but increasing host
> >> CPU usage to maximum)
> >>
> >> o 0.12 without any options is the fastest, and it keeps number
> >> of reloads to be within 3k/sec range during all time. here's
> >> typical kvm_stats of idle guest with 0.12:
> >>
>
> > Perhaps OpenBSD is accessing the HPET frequently, which is emulated
> > in userspace. Try disabling it with "-no-hpet".
>
> -no-hpet makes no visible difference, exactly the same thing as above:
>
> host_state_reload 21310655 43968
> exits 25007599 3573
> insn_emulation 22635201 3469
>
Can you do ftrace of kvm events?
--
Gleb.
^ permalink raw reply [flat|nested] 5+ messages in thread
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2011-03-11 12:02 *insane* amount of host_state_reloads for openbsd guest in 0.14 Michael Tokarev
2011-03-14 10:00 ` Daniel Bareiro
2011-03-16 19:48 ` Marcelo Tosatti
2011-03-16 19:55 ` Michael Tokarev
2011-03-17 7:24 ` Gleb Natapov
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