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Date:   Thu, 4 Feb 2021 15:59:01 +0100
From:   Peter Zijlstra <peterz@infradead.org>
To:     Dmitry Vyukov <dvyukov@google.com>
Cc:     Ingo Molnar <mingo@redhat.com>,
        Arnaldo Carvalho de Melo <acme@kernel.org>,
        Mark Rutland <mark.rutland@arm.com>,
        Alexander Shishkin <alexander.shishkin@linux.intel.com>,
        Jiri Olsa <jolsa@redhat.com>,
        Namhyung Kim <namhyung@kernel.org>,
        Will Deacon <will@kernel.org>,
        LKML <linux-kernel@vger.kernel.org>,
        Matt Morehouse <mascasa@google.com>
Subject: Re: Process-wide watchpoints
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On Thu, Feb 04, 2021 at 02:35:36PM +0100, Dmitry Vyukov wrote:

> I meant that we could restrict synchronous SIGTRAP for (1)
> perf_event_open(pid != 0) and (2) disable it after exec.

Hmm, I think I finally get what you're after. And yes, multi-process or
fork() based thingies are common and might well work too.

disable_on_exec isn't quite right though, it needs to be something that
kills the events entirely. I'll think about it.