[lttng-ust.git] / TODO

- remove libustconsumers dependency on libustsnprintf (usterr_signal_safe.h)
- correctly destroy buffers at trace destroy
- add multi-threaded test program
- add dlopen() based test program
- add automatic valgrind test of libust
- fix FIXME's in the code
- support multiple simultaneous traces
- add compilation tests
- fix the case where a lib is unloaded while markers are being connected with the auto probe connector. the marker mutex needs to be held to prevend the lib from being unloaded at that time. also, the library unregister function in marker.c should remove the markers from the hash table and call synchronize_rcu before returning
- add option to usttrace to select subbuffer size/count
- add option to see subbuffer size and count (need to test it)
- performance testing tool (in progress by Douglas Santos)
- profile with oprofile or similar to check for perf bottlenecks
- improve support for combined kernel/userspace tracing
- document API
- make sure the proper structures are cacheline aligned, and test performance, including multi-threaded
- fix header/lib priority problem at compilation
- port changes from recent versions of lttng kernel
- make cli interface for flight recorder
- save_registers: save them only when the marker is active (complicated because we need to know their value at the address that is put in struct marker)
- make streaming work, including periodical flush
- make a system (signal-based?) that allow the listener thread to not be started initially
- ust-consumerd should work as a pool of threads
- support more than one marker with the same channel and name on the same line?
- make a mode where the listener thread can poll buffers to check if they are ready to be collected
  This is to guarantee there will never be a system call in the tracing path. Currently there is a system
  call when the buffer is full to notify the listener it can be collected.
- In early tracing mode, the only channels that can be used reliably are "metadata" and "ust". The "usttrace" tool always uses early tracing and is hence subject to this limitation. Traces setup with the "ustctl" tool ("manual mode") are not subject to this limitation and can contain channels that have any name. Also, when loading a library with dlopen(), in order for markers in the library to generate events in the trace, these markers must be in the same channel as an event that was in the executable or its dynamically linked libraries that were loaded at start time. If using early tracing, only the "ust" channel can be used. Fix this. (RCU locking of channel structures in progress by Mathieu Desnoyers)
Commit	Line	Data
30ffe279	1	- remove libustconsumers dependency on libustsnprintf (usterr_signal_safe.h)
b6416778 PMF	2	- correctly destroy buffers at trace destroy
b6416778 PMF	3	- add multi-threaded test program
f50e9615 PMF	4	- add dlopen() based test program
f50e9615 PMF	5	- add automatic valgrind test of libust
5a5151f4	6	- fix FIXME's in the code
b6416778	7	- support multiple simultaneous traces
27a4f279	8	- add compilation tests
f50e9615	9	- fix the case where a lib is unloaded while markers are being connected with the auto probe connector. the marker mutex needs to be held to prevend the lib from being unloaded at that time. also, the library unregister function in marker.c should remove the markers from the hash table and call synchronize_rcu before returning
d9ba7a59	10	- add option to usttrace to select subbuffer size/count
b6416778 PMF	11	- add option to see subbuffer size and count (need to test it)
b6416778 PMF	12	- performance testing tool (in progress by Douglas Santos)
92b339a9	13	- profile with oprofile or similar to check for perf bottlenecks
3b74716b	14	- improve support for combined kernel/userspace tracing
972af454	15	- document API
1e066c2d	16	- make sure the proper structures are cacheline aligned, and test performance, including multi-threaded
eb4870e6	17	- fix header/lib priority problem at compilation
5a5151f4	18	- port changes from recent versions of lttng kernel
eb4870e6	19	- make cli interface for flight recorder
eb4870e6	20	- save_registers: save them only when the marker is active (complicated because we need to know their value at the address that is put in struct marker)
a0c822d0	21	- make streaming work, including periodical flush
5a5151f4	22	- make a system (signal-based?) that allow the listener thread to not be started initially
9dc7b7ff	23	- ust-consumerd should work as a pool of threads
a0c822d0	24	- support more than one marker with the same channel and name on the same line?
1808a771 PMF	25	- make a mode where the listener thread can poll buffers to check if they are ready to be collected
	26	This is to guarantee there will never be a system call in the tracing path. Currently there is a system
	27	call when the buffer is full to notify the listener it can be collected.
a0c822d0	28	- In early tracing mode, the only channels that can be used reliably are "metadata" and "ust". The "usttrace" tool always uses early tracing and is hence subject to this limitation. Traces setup with the "ustctl" tool ("manual mode") are not subject to this limitation and can contain channels that have any name. Also, when loading a library with dlopen(), in order for markers in the library to generate events in the trace, these markers must be in the same channel as an event that was in the executable or its dynamically linked libraries that were loaded at start time. If using early tracing, only the "ust" channel can be used. Fix this. (RCU locking of channel structures in progress by Mathieu Desnoyers)