Hi Jiri,
On 3/17/2021 6:06 PM, Jiri Olsa wrote:
On Wed, Mar 17, 2021 at 10:12:03AM +0800, Jin, Yao wrote:
On 3/16/2021 10:04 PM, Jiri Olsa wrote:
On Tue, Mar 16, 2021 at 09:49:42AM +0800, Jin, Yao wrote:
SNIP
Performance counter stats for 'system wide':
136,655,302 cpu_core/branch-instructions/
1.003171561 seconds time elapsed
So we need special rules for both cycles and branches.
The worse thing is, we also need to process the hardware cache events.
# ./perf stat -e cpu_core/LLC-loads/
event syntax error: 'cpu_core/LLC-loads/'
\___ unknown term 'LLC-loads' for pmu 'cpu_core'
valid terms:
event,pc,edge,offcore_rsp,ldlat,inv,umask,frontend,cmask,config,config1,config2,name,period,percore
Initial error:
event syntax error: 'cpu_core/LLC-loads/'
\___ unknown term 'LLC-loads' for pmu 'cpu_core'
If we use special rules for establishing all event mapping, that looks too
much. :(
hmmm but wait, currently we do not support events like this:
'cpu/cycles/'
'cpu/branches/'
the pmu style accepts only 'events' or 'format' terms within //
we made hw events like 'cycles','instructions','branches' special
to be used without the pmu
so why do we need to support cpu_code/cycles/ ?
jirka
Actually we have to support pmu style event for hybrid platform.
User may want to enable the events from specified pmus and also with flexible
grouping.
For example,
perf stat -e '{cpu_core/cycles/,cpu_core/instructions/}' -e
'{cpu_atom/cycles/,cpu_atom/instructions/}'
This usage is common and reasonable. So I think we may need to support pmu
style events.
sure, but we don't support 'cpu/cycles/' but we support 'cpu/cpu-cycles/'
why do you insist on supporting cpu_core/cycles/ ?
jirka
I'm OK to only support 'cpu_core/cpu-cycles/' or 'cpu_atom/cpu-cycles/'. But what would we do for
cache event?
'perf stat -e LLC-loads' is OK, but 'perf stat -e cpu/LLC-loads/' is not
supported currently.
For hybrid platform, user may only want to enable the LLC-loads on core CPUs or on atom CPUs. That's
reasonable. While if we don't support the pmu style event, how to satisfy this requirement?
If we can support the pmu style event, we can also use the same way for cpu_core/cycles/. At least
it's not a bad thing, right? :)
Thanks
Jin Yao
