Re: [RFC perf,bpf 1/5] perf, bpf: Introduce PERF_RECORD_BPF_EVENT

[Song Liu]

Hi David,

> On Nov 8, 2018, at 10:26 AM, David Ahern <dsahern@xxxxxxxxx> wrote:
> 
> On 11/8/18 11:04 AM, Song Liu wrote:
>> On the other hand, processing BPF load/unload events synchronously should
>> not introduce too much overhead for meaningful use cases. If many BPF progs
>> are being loaded/unloaded within short period of time, it is not the steady
>> state that profiling works care about. 
> 
> but, profiling is not the only use case, and perf-record is common with
> those other use cases.
> 
> I think that answers why your RFC set does not fork a thread for the bpf
> events. You are focused on profiling and for already loaded programs or
> for a small number of programs loaded by a specific workload started by
> perf.

We sure can fork a thread for the BPF event. But I guess that's not Peter's
main concern here...

Could you please point me to more information about the use cases you worry 
about? I am more than happy to optimize the logic for those use cases. 

Thanks,
Song