* [Qemu-devel] Question on cpu_interrupt()
@ 2010-04-29 16:22 Jiaqing Du
0 siblings, 0 replies; only message in thread
From: Jiaqing Du @ 2010-04-29 16:22 UTC (permalink / raw)
To: qemu-devel
Hi,
I am trying to inject NMIs to a guest running in QEMU by using
cpu_interrupt(). I notice that QEMU slows down significantly when NMIs
are being injected.
The injected NMIs per second is around 10. QEMU is pined to one core.
A computation intensive application runs in the guest. When no NMIs
are being injected, the physical CPU utilization is 100%; while NMIs
are injected by calling cpu_interrupt(), the physical CPU utilization
rate drops to around 30%. As far as I know from reading the code,
cpu_interrupt() unchains the translation cache. So when the current TB
is executed over, QEMU code is executed to handle the interrupt. I
also notice that cpu_interrupt() is called very frequently normally.
Why QEMU's performance drops so much when NMIs are being injected?
Please CC me your reply.
Thanks,
Jiaqing
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