From mboxrd@z Thu Jan  1 00:00:00 1970
From: Alexei Starovoitov <ast@plumgrid.com>
Subject: Re: [PATCH V5 1/1] bpf: control events stored in PERF_EVENT_ARRAY
 maps trace data output when perf sampling
Date: Wed, 21 Oct 2015 20:09:19 -0700
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Cc: xiakaixu <xiakaixu@huawei.com>, davem@davemloft.net,
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To: "Wangnan (F)" <wangnan0@huawei.com>,
	Peter Zijlstra <peterz@infradead.org>
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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?