From: Namhyung Kim <namhyung@kernel.org>
To: Sam James <sam@gentoo.org>
Cc: fweimer@redhat.com, akpm@linux-foundation.org, andrii@kernel.org,
axboe@kernel.dk, beaub@linux.microsoft.com, bpf@vger.kernel.org,
indu.bhagat@oracle.com, jemarch@gnu.org, jolsa@kernel.org,
jpoimboe@kernel.org, jremus@linux.ibm.com,
linux-kernel@vger.kernel.org, linux-trace-kernel@vger.kernel.org,
mathieu.desnoyers@efficios.com, mhiramat@kernel.org,
mingo@kernel.org, peterz@infradead.org, rostedt@goodmis.org,
tglx@linutronix.de, torvalds@linux-foundation.org,
x86@kernel.org
Subject: Re: [PATCH v11 00/14] unwind_user: x86: Deferred unwinding infrastructure
Date: Wed, 2 Jul 2025 10:10:25 -0700 [thread overview]
Message-ID: <aGVoAT6asYLUx4He@google.com> (raw)
In-Reply-To: <87wm8qlsuk.fsf@gentoo.org>
Hello,
On Wed, Jul 02, 2025 at 12:44:51PM +0100, Sam James wrote:
> I started to play around with this properly last night and it was
> straightforward, fortunately.
>
> Did initially attempt to backport to 6.15 but it was a victim of some
> mm refactoring and didn't seem worth to carry on w/ that route.
>
> Started a rough page with notes for myself (but corrections & such
> welcome) at https://wiki.gentoo.org/wiki/Project:Toolchain/SFrame but
> honestly, it's immediately obvious (and beautiful) when it's working
> correctly. I've used Namhyung Kim's example from this thread but you can
> see it easily with `perf top -g` too.
I've looked at the page but it doesn't seem to work well unfortunately.
The working case has the symbols correct but the overheads are same.
It should have more 'Children' overhead than 'Self' like in the broken
case because 'children = self + callchain'.
Thanks,
Namhyung
>
> In one of the commit messages in the perf series, Steven also gave `perf
> record -g -vv true` which was convenient for making sure it's correctly
> discovered deferred unwinding support.
>
> I plan on doing measurements next and doing some more playing once I've
> built more userland with it.
prev parent reply other threads:[~2025-07-02 17:10 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-06-25 22:56 [PATCH v11 00/14] unwind_user: x86: Deferred unwinding infrastructure Steven Rostedt
2025-06-25 22:56 ` [PATCH v11 01/14] unwind_user: Add user space unwinding API Steven Rostedt
2025-06-25 22:56 ` [PATCH v11 02/14] unwind_user: Add frame pointer support Steven Rostedt
2025-06-25 22:56 ` [PATCH v11 03/14] unwind_user: Add compat mode " Steven Rostedt
2025-06-25 22:56 ` [PATCH v11 04/14] unwind_user/deferred: Add unwind_user_faultable() Steven Rostedt
2025-06-25 22:56 ` [PATCH v11 05/14] unwind_user/deferred: Add unwind cache Steven Rostedt
2025-06-25 22:56 ` [PATCH v11 06/14] unwind_user/deferred: Add deferred unwinding interface Steven Rostedt
2025-06-26 16:48 ` Steven Rostedt
2025-06-26 20:34 ` Steven Rostedt
2025-06-25 22:56 ` [PATCH v11 07/14] unwind_user/deferred: Make unwind deferral requests NMI-safe Steven Rostedt
2025-06-25 22:56 ` [PATCH v11 08/14] unwind deferred: Use bitmask to determine which callbacks to call Steven Rostedt
2025-06-25 22:56 ` [PATCH v11 09/14] unwind deferred: Use SRCU unwind_deferred_task_work() Steven Rostedt
2025-06-25 22:56 ` [PATCH v11 10/14] unwind: Clear unwind_mask on exit back to user space Steven Rostedt
2025-06-25 22:56 ` [PATCH v11 11/14] unwind: Finish up unwind when a task exits Steven Rostedt
2025-06-25 22:56 ` [PATCH v11 12/14] unwind_user/x86: Enable frame pointer unwinding on x86 Steven Rostedt
2025-06-25 22:56 ` [PATCH v11 13/14] perf/x86: Rename and move get_segment_base() and make it global Steven Rostedt
2025-06-26 8:44 ` Ingo Molnar
2025-06-26 12:13 ` Steven Rostedt
2025-06-26 13:07 ` Peter Zijlstra
2025-06-26 15:13 ` Steven Rostedt
2025-06-25 22:56 ` [PATCH v11 14/14] unwind_user/x86: Enable compat mode frame pointer unwinding on x86 Steven Rostedt
2025-06-26 8:33 ` Ingo Molnar
2025-06-26 12:12 ` Steven Rostedt
2025-06-27 14:01 ` Steven Rostedt
2025-06-27 16:23 ` Linus Torvalds
2025-06-30 12:50 ` [PATCH v11 00/14] unwind_user: x86: Deferred unwinding infrastructure Florian Weimer
2025-06-30 16:35 ` Namhyung Kim
2025-06-30 17:30 ` Steven Rostedt
2025-07-02 11:44 ` Sam James
2025-07-02 16:15 ` Steven Rostedt
2025-07-02 17:14 ` Namhyung Kim
2025-07-03 4:01 ` Sam James
2025-07-02 17:10 ` Namhyung Kim [this message]
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