perf tools: Add attr<num> syntax to event parser
The event parser is limited to update only a subset of all fields in
struct perf_event_attr (config*, period, branch_type). We are not able
to set other attr fields, esp. flags.
Introducing a new syntax to set any field of the event attribute by
using an index to the u64 value to be used within struct
perf_event_attr. The new syntax attr<num> is similar to config<num>,
but <num> specifies the index to be used. E.g. attr5:23 sets bit 23 of
the flag field of attr.
The persistent event implementation is a use case of the above. In
this case sysfs provides:
/sys/bus/event_source/devices/persistent/events/mce_record:persistent,config=106
/sys/bus/event_source/devices/persistent/format/persistent:attr5:23
Persistent events are exposed via sysfs and need to set the persistent
flag (bit 23 of the flag field). With the sysfs entry above we are
able to define the persistent flag format and then may setup a
mce_record event with that flag set.
In general we are now flexible to describe with sysfs any event to be
setup by perf tools.
Signed-off-by: Robert Richter <robert.richter@linaro.org>
Signed-off-by: Robert Richter <rric@kernel.org>
5 files changed
