Il 02/02/2014 03:08, Xin Tong ha scritto:
I am getting very weird profile results by running operf on linux on
the host and profiling the a kvm virtual machine running dacapo
eclipse benchmark. I am expecting a lot of time should be spent in
the qemu-system-x86_64 as the instructions from the eclipse benchmark
would be treated as part of the qemu-system-x86_64 process, but the
results tell different. any suggestions ?
Most of the time should be spent running the guest. This is in the
context of process qemu-system-x86_64, but it is not running code from
the qemu executable.
What likely happens is that when the profiling counter expires, it
causes the VM to exit before the profiling interrupt is delivered. The
sample should then be associated to the kvm_intel module.
31.5% in the KVM module seems like a lot. Can you detail the results
further, so that I can see the function names for kvm and kvm_intel?
Paolo
CPU_CLK_UNHALTED % Module
Symbol/Functions
1054 31.49 /kvm
/kvm
645 19.27 /kvm_intel
/kvm_intel
248 7.41
/home/xtong/qemu-kvm-1.2.0/install/bin/qemu-system-x86_64
/home/xtong/qemu-kvm-1.2.0/install/bin/qemu-system-x86_64
215 6.42 /usr/lib/debug/boot/vmlinux-3.11.0-13-generic
native_write_msr_safe
101 3.02 /usr/lib/debug/boot/vmlinux-3.11.0-13-generic
native_read_msr_safe
93 2.78 /lib/x86_64-linux-gnu/libc-2.15.so
/lib/x86_64-linux-gnu/libc-2.15.so
77 2.30 /lib/x86_64-linux-gnu/libglib-2.0.so.0.3200.4
/lib/x86_64-linux-gnu/libglib-2.0.so.0.3200.4
65 1.94 /usr/lib/debug/boot/vmlinux-3.11.0-13-generic
__srcu_read_lock
48 1.43 /usr/lib/debug/boot/vmlinux-3.11.0-13-generic
__srcu_read_unlock
40 1.20 /usr/lib/debug/boot/vmlinux-3.11.0-13-generic
native_load_tr_desc
29 0.87 /usr/lib/debug/boot/vmlinux-3.11.0-13-generic
__ticket_spin_lock
25 0.75 /usr/lib/debug/boot/vmlinux-3.11.0-13-generic
guest_exit
21 0.63 /usr/lib/debug/boot/vmlinux-3.11.0-13-generic
native_load_gdt
...
Thank you.
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