new syntax for perf event

[Jiri Olsa <jolsa@redhat.com>]

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}