On Tue, 13 Mar 2018 11:14:01 +0100 Jiri Olsa <jo...@redhat.com> wrote:
> > Jiri, If you apply the below, does it fix it for you? > > yes, the crash is gone and I can set filter ftrace/function, Great! > but I'm still having some issues put that filter through perf > > # perf record -e ftrace:function --filter "ip == 0xffffffffa41e8490" ls > > but I might be just missing something.. it's been a while ;-) I'm looking to > that I have to ask. Did that work with the old code? The ftrace filter was special in the old code and I tried to simulate it in the new code. I'm not sure I checked if ip can take an address, but from what the code looked like, it wouldn't. It looked like it required a name of a function. Something that gets passed into "set_ftrace_filter" which is not an address. So instead of doing something like: perf record -e ftrace:function --filter "ip == 0xffffffff810ccfa0" ls You would need to do perf record -e ftrace:function --filter "ip == schedule_tail" ls because perf doesn't use the filter for the function, it uses the ftrace_ops->hash tables. If it would simply take the address, we could just use the trace_events_filter logic, and not make it a special case. -- Steve