[ Adding Vince...]
On 2017/07/12 12:48PM, Jiri Olsa wrote: > On Mon, Jun 19, 2017 at 08:01:06PM +0530, Naveen N. Rao wrote: > > Currently, there is no way to ask for signals to be delivered when a > > certain number of sideband events have been logged into the ring buffer. > > This is problematic if we are only interested in, say, context switch > > events. Furthermore, signals are more useful (rather than polling) for > > self-profiling. This series provides for a way to achieve this. > > > > We ride on top of the existing support for ring buffer wakeup to > > generate signals as desired. Counting sideband events still requires > > some changes in the output path, but in normal cases, it ends up being > > just a comparison. > > > > The test program below demonstrates how a process can profile itself for > > context switch events and how it can control notification through > > signals. The key changes include the below perf_event_attr settings as > > well as use of IOC_ENABLE: > > pe.signal_on_wakeup = 1; > > pe.count_sb_events = 1; > > pe.wakeup_events = 2; > > Vince, > could you please check on this? thanks > > Naveen, > have you run Vince's test suite on this? > http://github.com/deater/perf_event_tests.git I just tried this and I see quite a few failures even without these patches. The behavior is similar with/without these patches and all the ioctl tests pass, but I see some failures with the overflow tests. I'll look into those tests in detail tomorrow. I may be missing something. Thanks, Naveen
