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Date:   Tue, 20 Aug 2019 16:45:03 +0200
From:   Peter Zijlstra <peterz@infradead.org>
To:     Daniel Xu <dxu@dxuuu.xyz>
Cc:     bpf@vger.kernel.org, songliubraving@fb.com, yhs@fb.com,
        andriin@fb.com, mingo@redhat.com, acme@kernel.org, ast@fb.com,
        alexander.shishkin@linux.intel.com, jolsa@redhat.com,
        namhyung@kernel.org, linux-kernel@vger.kernel.org,
        kernel-team@fb.com
Subject: Re: [PATCH v3 bpf-next 1/4] tracing/probe: Add
 PERF_EVENT_IOC_QUERY_PROBE ioctl
Message-ID: <20190820144503.GV2332@hirez.programming.kicks-ass.net>
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 <20190816223149.5714-2-dxu@dxuuu.xyz>
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On Fri, Aug 16, 2019 at 03:31:46PM -0700, Daniel Xu wrote:
> It's useful to know [uk]probe's nmissed and nhit stats. For example with
> tracing tools, it's important to know when events may have been lost.
> debugfs currently exposes a control file to get this information, but
> it is not compatible with probes registered with the perf API.

What is this nmissed and nhit stuff?