Re: [PATCH v3 bpf-next 1/4] tracing/probe: Add PERF_EVENT_IOC_QUERY_PROBE ioctl

From: Yonghong Song
Date: Wed Aug 21 2019 - 18:12:16 EST

On 8/21/19 1:07 PM, Arnaldo Carvalho de Melo wrote:
> Em Wed, Aug 21, 2019 at 04:54:47PM +0000, Yonghong Song escreveu:
>> Arnaldo has a question on bcc mailing list about the hit/miss
>> counting of bpf program missed to process events.
> PERF_FORMAT_LOST seems to be a good answer to that? See my other reply
> to this thread.

Just checked. indeed adding PERF_FORMAT_LOST to perf read_format
seems a reasonable approach. ioctl with perf_event_open fd can do the
same thing, but ioctl should be avoided if we have alternatives.

Thanks for the pointer!

> - Arnaldo