From: Michael Jeanson <mjeanson@efficios.com>
To: Steven Rostedt <rostedt@goodmis.org>
Cc: linux-kernel@vger.kernel.org,
Peter Zijlstra <peterz@infradead.org>,
Alexei Starovoitov <ast@kernel.org>, Yonghong Song <yhs@fb.com>,
"Paul E . McKenney" <paulmck@kernel.org>,
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>,
Joel Fernandes <joel@joelfernandes.org>,
bpf@vger.kernel.org,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Subject: Re: [RFC PATCH 0/6] [RFC] Faultable tracepoints (v2)
Date: Wed, 24 Feb 2021 11:22:03 -0500 [thread overview]
Message-ID: <083bce0f-bd66-ab83-1211-be9838499b45@efficios.com> (raw)
In-Reply-To: <20210223211639.670db85c@gandalf.local.home>
[ Adding Mathieu Desnoyers in CC ]
On 2021-02-23 21 h 16, Steven Rostedt wrote:
> On Thu, 18 Feb 2021 17:21:19 -0500
> Michael Jeanson <mjeanson@efficios.com> wrote:
>
>> This series only implements the tracepoint infrastructure required to
>> allow tracers to handle page faults. Modifying each tracer to handle
>> those page faults would be a next step after we all agree on this piece
>> of instrumentation infrastructure.
>
> I started taking a quick look at this, and came up with the question: how
> do you allow preemption when dealing with per-cpu buffers or storage to
> record the data?
>
> That is, perf, bpf and ftrace are all using some kind of per-cpu data, and
> this is the reason for the need to disable preemption. What's the solution
> that LTTng is using for this? I know it has a per cpu buffers too, but does
> it have some kind of "per task" buffer that is being used to extract the
> data that can fault?
>
> -- Steve
>
next prev parent reply other threads:[~2021-02-24 16:22 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-02-18 22:21 [RFC PATCH 0/6] [RFC] Faultable tracepoints (v2) Michael Jeanson
2021-02-18 22:21 ` [RFC PATCH 1/6] tracing: introduce faultable " Michael Jeanson
2021-02-18 22:21 ` [RFC PATCH 2/6] tracing: ftrace: add support for faultable tracepoints Michael Jeanson
2021-02-18 22:21 ` [RFC PATCH 3/6] tracing: bpf-trace: " Michael Jeanson
2021-02-18 22:21 ` [RFC PATCH 4/6] tracing: perf: " Michael Jeanson
2021-02-18 22:21 ` [RFC PATCH 5/6] tracing: convert sys_enter/exit to " Michael Jeanson
2021-02-18 22:21 ` [RFC PATCH 6/6] tracing: use Tasks Trace RCU instead of SRCU for rcuidle tracepoints Michael Jeanson
2021-02-24 2:16 ` [RFC PATCH 0/6] [RFC] Faultable tracepoints (v2) Steven Rostedt
2021-02-24 16:22 ` Michael Jeanson [this message]
2021-02-24 16:59 ` Mathieu Desnoyers
2021-02-24 18:14 ` Steven Rostedt
2021-02-25 21:46 ` Mathieu Desnoyers
2021-02-24 23:54 ` Mathieu Desnoyers
2021-02-26 5:28 ` Lai Jiangshan
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