new syntax for perf event

From: Jiri Olsa
Date: Wed Dec 21 2011 - 11:16:41 EST


On Tue, Dec 20, 2011 at 12:39:21PM +0100, Peter Zijlstra wrote:
> On Tue, 2011-12-20 at 12:30 +0100, Peter Zijlstra wrote:
> > event config-0:7
> > umask config-8:15
> > usr config-16
> > os config-17
> > edge config-18
> > any config-21
> > inv config-23
> > cmask config-24:31
> >
> > nhm-dmnd_data_rd config1-0
> > nhm-dmnd_rfo config1-1
> > nhm-dmnd_ifetch config1-2
> > ...
> >
> > (the real syntax will likely be a little more complex in order to be
> > able to express the various other architectures their raw input format).
>
> for instance AMD would need:
>
> event config-0:7,32-35
> guest config-40
> host config-41
>
> (assuming you read that as a mask from LSB to MSB)
>
> And I still haven't actually read how the P4 works so I can't help out
> there.


ok first try ;) description + grammar attached

- event has a general format:
pmu/event_def[:modifier] [ ',' pmu/event_def[:modifier] ] ...

where event_def depends on the chosen pmu:
'cpu' 'tracepoint' 'breakpoint'


- to keep some of the old interface, symbolic and cache events stays,
since they are recognizable by keywords (event_symbol, event_cache)


- raw events are defined with the help of event keywords like:
cpu/raw,config=1,config1=0,config2=0
cpu/hw,config=1,config1=0

* first symbol after '/' defines the type: raw/hw/cache
which match PERF_TYPE_RAW/PERF_TYPE_HARDWARE/PERF_TYPE_HW_CACHE

* the rest consists assignments for 'config/config1/config1' keywords
that match with the perf_event_attr:config/config1/config values
(possibly extended once we have sysfs events representation)


- tracepoint events are defined like:
tracepoint/system:tracepoint

where tracepoint could contain '*?'


- breakpoint events are defined like:
breakpoint/addr:type


- each event could be followed by modifier definition


- I think pmu names should match registered pmu names,
but we could make some shortcuts so we dont need to type 'tracepoint/',
but just 'tp/' or smth..


- as for tracepoints it looks like the old format does not clash with the new one
and we could add shortcut (omit the 'tracepoint/') like:
event: event_tracepoint


- not sure I should include 'software' pmu, as it seems to covered by
event_symbol events


thanks for comments,
jirka



grammar
-------
events:
event_mod ',' event_mod | event_mod

event_mod:
event | event ':' modifier

event:
event_symbol |
event_cache |
'cpu' '/' event_cpu |
'tracepoint' '/' event_tracepoint
'breakpoint' '/' event_breakpoint

event_symbol:
cpu-cycles|cycles
stalled-cycles-frontend|idle-cycles-frontend
stalled-cycles-backend|idle-cycles-backend
instructions
cache-references
cache-misses
branch-instructions|branches
branch-misses
bus-cycles
cpu-clock
task-clock
page-faults|faults
minor-faults
major-faults
context-switches|cs
cpu-migrations|migrations
alignment-faults
emulation-faults

event_cache:
cache_type
cache_type '-' cache_result_op
cache_type '-' cache_result_op '-' cache_result_op

cache_type:
L1-dcache|l1-d|l1d|L1-data
L1-icache|l1-i|l1i|L1-instruction
LLC|L2
dTLB|d-tlb|Data-TLB
iTLB|i-tlb|Instruction-TLB
branch|branches|bpu|btb|bpc
node

cache_result_op:
load|loads|read
store|stores|write
prefetch|prefetches
speculative-read|speculative-load
refs|Reference|ops|access
misses|miss

event_cpu:
'raw' ',' event_cpu_def
'hw' ',' event_cpu_def
'cache' ',' event_cpu_def

event_cpu_def:
event_cpu_ass ',' event_cpu_ass |
event_cpu_ass

event_cpu_ass:
event_cpu_elem '=' value

event_cpu_elem:
'config' | 'config1' | 'config2'

event_tracepoint:
system ':' tracepoint

event_breakpoint:
addr ':' type

modifier:
[ukhp]{1,4}
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