Re: [PATCH V5 1/1] bpf: control events stored in PERF_EVENT_ARRAY maps trace data output when perf sampling

From: Alexei Starovoitov
Date: Wed Oct 21 2015 - 23:09:26 EST


On 10/21/15 6:56 PM, Wangnan (F) wrote:
One alternative solution I can image is to attach a BPF program
at sampling like kprobe, and return 0 if we don't want sampling
take action. Thought?

Do you think attaching BPF programs to sampling is an acceptable idea?

If you mean to extend 'filter' concept to sampling events?
So instead of soft_disable of non-local events, you'll attach bpf
program to sampling events and use map lookup to decide whether
to filter out or not such sampling event?
What pt_regs would be in such case?

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