Every event in the perf-kvm has a 'stats' structure, which contains
max/min/average/etc times of handling this event.
The problem is that the 'perf-kvm stat report' command always shows
that 'min time' is 0us for every event. Example:
# perf kvm stat report
Analyze events for all VCPUs:
VM-EXIT Samples Samples% Time% Min Time Max Time Avg time
[..]
0xB2 MSCH 12 0.07% 0.00% 0us 8us 7.31us ( +- 2.11% )
0xB2 CHSC 12 0.07% 0.00% 0us 18us 9.39us ( +- 9.49% )
0xB2 STPX 8 0.05% 0.00% 0us 2us 1.88us ( +- 7.18% )
0xB2 STSI 7 0.04% 0.00% 0us 44us 16.49us ( +- 38.20% )
[..]
This happens because the 'stats' structure is not initialized and
stats->min equals to 0. Lets initialize the structure for every
event after its allocation using init_stats() function. This initializes
stats->min to -1 and makes 'Min time' statistics counting work:
# perf kvm stat report
Analyze events for all VCPUs:
VM-EXIT Samples Samples% Time% Min Time Max Time Avg time
[..]
0xB2 MSCH 12 0.07% 0.00% 6us 8us 7.31us ( +- 2.11% )
0xB2 CHSC 12 0.07% 0.00% 7us 18us 9.39us ( +- 9.49% )
0xB2 STPX 8 0.05% 0.00% 1us 2us 1.88us ( +- 7.18% )
0xB2 STSI 7 0.04% 0.00% 1us 44us 16.49us ( +- 38.20% )
[..]
Signed-off-by: Alexander Yarygin <yarygin@linux.vnet.ibm.com>
Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Reviewed-by: David Ahern <dsahern@gmail.com>
Link: http://lkml.kernel.org/r/1397053319-2130-3-git-send-email-borntraeger@de.ibm.com
[ Fixing the perf examples changelog output ]
Signed-off-by: Jiri Olsa <jolsa@redhat.com>
acb61fc8ed