From: Steven Rostedt <rostedt@goodmis.org>
To: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>,
Peter Zijlstra <peterz@infradead.org>,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
bpf@vger.kernel.org, x86@kernel.org,
Masami Hiramatsu <mhiramat@kernel.org>,
Josh Poimboeuf <jpoimboe@kernel.org>,
Ingo Molnar <mingo@kernel.org>, Jiri Olsa <jolsa@kernel.org>,
Namhyung Kim <namhyung@kernel.org>,
Thomas Gleixner <tglx@linutronix.de>,
Andrii Nakryiko <andrii@kernel.org>,
Indu Bhagat <indu.bhagat@oracle.com>,
"Jose E. Marchesi" <jemarch@gnu.org>,
Beau Belgrave <beaub@linux.microsoft.com>,
Jens Remus <jremus@linux.ibm.com>,
Andrew Morton <akpm@linux-foundation.org>,
Jens Axboe <axboe@kernel.dk>, Florian Weimer <fweimer@redhat.com>
Subject: Re: [PATCH v12 06/14] unwind_user/deferred: Add deferred unwinding interface
Date: Wed, 2 Jul 2025 15:51:22 -0400 [thread overview]
Message-ID: <20250702155122.46db0cdc@batman.local.home> (raw)
In-Reply-To: <707898da-a3d4-4cdb-816a-6a2e5a3cb03d@efficios.com>
On Wed, 2 Jul 2025 15:43:08 -0400
Mathieu Desnoyers <mathieu.desnoyers@efficios.com> wrote:
> From my perspective, making trace analysis results reliable is the most
> basic guarantee tooling should provide in order to make it trusted by
> users. So I am tempted to err towards robustness rather than take
> shortcuts because "it does not happen often".
Another solution which I'm thinking of doing for perf is to simply
state: a deferred stack trace does not go to any event before events
were dropped.
That is, even if the stack trace is associated, if events are dropped
before getting out of the kernel, just say, "Sorry, the events before
the dropped events lost its user stack trace".
That may better, as having no data is better than incorrect data.
-- Steve
next prev parent reply other threads:[~2025-07-02 19:51 UTC|newest]
Thread overview: 53+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-07-01 0:53 [PATCH v12 00/14] unwind_user: x86: Deferred unwinding infrastructure Steven Rostedt
2025-07-01 0:53 ` [PATCH v12 01/14] unwind_user: Add user space unwinding API Steven Rostedt
2025-07-04 17:58 ` Mathieu Desnoyers
2025-07-04 18:20 ` Mathieu Desnoyers
2025-07-07 19:42 ` Steven Rostedt
2025-07-07 21:01 ` Steven Rostedt
2025-07-01 0:53 ` [PATCH v12 02/14] unwind_user: Add frame pointer support Steven Rostedt
2025-07-01 2:10 ` Linus Torvalds
2025-07-01 2:56 ` Steven Rostedt
2025-07-01 3:05 ` Steven Rostedt
2025-07-01 15:36 ` Jens Remus
2025-07-02 23:50 ` Steven Rostedt
2025-07-03 16:21 ` Jens Remus
2025-07-07 21:28 ` Steven Rostedt
2025-07-01 4:46 ` Florian Weimer
2025-07-01 12:14 ` Steven Rostedt
2025-07-01 0:53 ` [PATCH v12 03/14] unwind_user: Add compat mode " Steven Rostedt
2025-07-01 0:53 ` [PATCH v12 04/14] unwind_user/deferred: Add unwind_user_faultable() Steven Rostedt
2025-07-01 0:53 ` [PATCH v12 05/14] unwind_user/deferred: Add unwind cache Steven Rostedt
2025-07-01 0:53 ` [PATCH v12 06/14] unwind_user/deferred: Add deferred unwinding interface Steven Rostedt
2025-07-02 16:36 ` Peter Zijlstra
2025-07-02 16:42 ` Steven Rostedt
2025-07-02 16:56 ` Linus Torvalds
2025-07-02 17:26 ` Steven Rostedt
2025-07-02 17:48 ` Steven Rostedt
2025-07-02 18:21 ` Linus Torvalds
2025-07-02 18:47 ` Mathieu Desnoyers
2025-07-02 19:05 ` Steven Rostedt
2025-07-02 19:12 ` Mathieu Desnoyers
2025-07-02 19:21 ` Steven Rostedt
2025-07-02 19:36 ` Steven Rostedt
2025-07-02 19:40 ` Steven Rostedt
2025-07-02 19:48 ` Mathieu Desnoyers
2025-07-02 20:10 ` Steven Rostedt
2025-07-02 19:43 ` Mathieu Desnoyers
2025-07-02 19:51 ` Steven Rostedt [this message]
2025-07-02 18:57 ` Steven Rostedt
2025-07-01 0:53 ` [PATCH v12 07/14] unwind_user/deferred: Make unwind deferral requests NMI-safe Steven Rostedt
2025-07-02 15:53 ` Jens Remus
2025-07-02 19:11 ` Steven Rostedt
2025-07-01 0:53 ` [PATCH v12 08/14] unwind deferred: Use bitmask to determine which callbacks to call Steven Rostedt
2025-07-01 0:53 ` [PATCH v12 09/14] unwind deferred: Use SRCU unwind_deferred_task_work() Steven Rostedt
2025-07-01 0:53 ` [PATCH v12 10/14] unwind: Clear unwind_mask on exit back to user space Steven Rostedt
2025-07-01 0:53 ` [PATCH v12 11/14] unwind: Add USED bit to only have one conditional on way " Steven Rostedt
2025-07-01 0:53 ` [PATCH v12 12/14] unwind: Finish up unwind when a task exits Steven Rostedt
2025-07-01 0:53 ` [PATCH v12 13/14] unwind_user/x86: Enable frame pointer unwinding on x86 Steven Rostedt
2025-07-01 0:53 ` [PATCH v12 14/14] unwind_user/x86: Enable compat mode " Steven Rostedt
2025-07-01 2:06 ` [PATCH v12 00/14] unwind_user: x86: Deferred unwinding infrastructure Linus Torvalds
2025-07-01 2:45 ` Steven Rostedt
2025-07-01 22:49 ` Kees Cook
2025-07-01 23:26 ` Steven Rostedt
2025-07-02 14:56 ` Kees Cook
2025-07-02 16:20 ` Mathieu Desnoyers
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