Powerpc provides hcall events that also provides insights into guest
behaviour. Enhance perf kvm stat to record and analyze hcall events.
- To trace hcall events :
perf kvm stat record
- To show the results :
perf kvm stat report --event=hcall
The result shows the number of hypervisor calls from the guest grouped
by their respective reasons displayed with the frequency.
This patch makes use of two additional tracepoints
"kvm_hv:kvm_hcall_enter" and "kvm_hv:kvm_hcall_exit". To map the hcall
codes to their respective names, it needs a mapping. Such mapping is
added in this patch in book3s_hcalls.h.
# pgrep qemu
A sample output :
19378
60515
2 VMs running.
# perf kvm stat record -a
^C[ perf record: Woken up 1 times to write data ]
[ perf record: Captured and wrote 4.153 MB perf.data.guest (39624
samples) ]
# perf kvm stat report -p 60515 --event=hcall
Analyze events for all VMs, all VCPUs:
HCALL-EVENT Samples Samples% Time% MinTime MaxTime AvgTime
H_IPI 822 66.08% 88.10% 0.63us 11.38us 2.05us (+- 1.42%)
H_SEND_CRQ 144 11.58% 3.77% 0.41us 0.88us 0.50us (+- 1.47%)
H_VIO_SIGNAL 118 9.49% 2.86% 0.37us 0.83us 0.47us (+- 1.43%)
H_PUT_TERM_CHAR 76 6.11% 2.07% 0.37us 0.90us 0.52us (+- 2.43%)
H_GET_TERM_CHAR 74 5.95% 2.23% 0.37us 1.70us 0.58us (+- 4.77%)
H_RTAS 6 0.48% 0.85% 1.10us 9.25us 2.70us (+-48.57%)
H_PERFMON 4 0.32% 0.12% 0.41us 0.96us 0.59us (+-20.92%)
Total Samples:1244, Total events handled time:1916.69us.
Signed-off-by: Hemant Kumar <hemant@linux.vnet.ibm.com>
Cc: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Cc: David Ahern <dsahern@gmail.com>
Cc: Michael Ellerman <mpe@ellerman.id.au>
Cc: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Scott Wood <scottwood@freescale.com>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/1453962787-15376-4-git-send-email-hemant@linux.vnet.ibm.com
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>
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