From: Peter Zijlstra <peterz@infradead.org>
To: Namhyung Kim <namhyung@kernel.org>
Cc: rcu@vger.kernel.org, intel-gfx@lists.freedesktop.org,
Boqun Feng <boqun.feng@gmail.com>,
LKML <linux-kernel@vger.kernel.org>,
Steven Rostedt <rostedt@goodmis.org>,
Radoslaw Burny <rburny@google.com>,
Byungchul Park <byungchul.park@lge.com>,
"Paul E. McKenney" <paul.mckenney@linaro.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
cgroups@vger.kernel.org, Tejun Heo <tj@kernel.org>,
Waiman Long <longman@redhat.com>,
Thomas Gleixner <tglx@linutronix.de>,
Will Deacon <will@kernel.org>, Ingo Molnar <mingo@kernel.org>,
linux-btrfs@vger.kernel.org
Subject: Re: [RFC 00/12] locking: Separate lock tracepoints from lockdep/lock_stat (v1)
Date: Wed, 9 Feb 2022 10:09:08 +0100 [thread overview]
Message-ID: <20220209090908.GK23216@worktop.programming.kicks-ass.net> (raw)
In-Reply-To: <20220208184208.79303-1-namhyung@kernel.org>
On Tue, Feb 08, 2022 at 10:41:56AM -0800, Namhyung Kim wrote:
> Eventually I'm mostly interested in the contended locks only and I
> want to reduce the overhead in the fast path. By moving that, it'd be
> easy to track contended locks with timing by using two tracepoints.
So why not put in two new tracepoints and call it a day?
Why muck about with all that lockdep stuff just to preserve the name
(and in the process continue to blow up data structures etc..). This
leaves distros in a bind, will they enable this config and provide
tracepoints while bloating the data structures and destroying things
like lockref (which relies on sizeof(spinlock_t)), or not provide this
at all.
Yes, the name is convenient, but it's just not worth it IMO. It makes
the whole proposition too much of a trade-off.
Would it not be possible to reconstruct enough useful information from
the lock callsite?
next prev parent reply other threads:[~2022-02-09 9:09 UTC|newest]
Thread overview: 28+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-02-08 18:41 [RFC 00/12] locking: Separate lock tracepoints from lockdep/lock_stat (v1) Namhyung Kim
[not found] ` <20220208184208.79303-1-namhyung-DgEjT+Ai2ygdnm+yROfE0A@public.gmane.org>
2022-02-08 18:41 ` [PATCH 02/12] cgroup: rstat: Make cgroup_rstat_cpu_lock name readable Namhyung Kim
2022-02-08 18:46 ` Tejun Heo
[not found] ` <YgK6k4TXnRbm02dh-NiLfg/pYEd1N0TnZuCh8vA@public.gmane.org>
2022-02-08 19:16 ` Namhyung Kim
[not found] ` <CAM9d7cgKLycpFuXq0VgC=ADtAipXtKdfRcDqvZwMrNBz7hXd7A-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2022-02-08 23:51 ` Namhyung Kim
2022-02-08 19:14 ` [RFC 00/12] locking: Separate lock tracepoints from lockdep/lock_stat (v1) Namhyung Kim
2022-02-09 9:09 ` Peter Zijlstra [this message]
2022-02-09 18:19 ` Waiman Long
[not found] ` <24fe6a08-5931-8e8d-8d77-459388c4654e-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2022-02-09 18:29 ` Mathieu Desnoyers
2022-02-09 19:02 ` Waiman Long
[not found] ` <69e5f778-8715-4acf-c027-58b6ec4a9e77-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2022-02-09 19:17 ` Mathieu Desnoyers
2022-02-09 19:37 ` Waiman Long
2022-02-09 19:22 ` Namhyung Kim
[not found] ` <CAM9d7ci=N2NVj57k=W0ebqBzfW+ThBqYSrx-CZbgwGcbOSrEGA-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2022-02-09 19:28 ` Mathieu Desnoyers
2022-02-09 19:45 ` Namhyung Kim
[not found] ` <CAM9d7cj=tj6pA48q_wkQOGn-2vUc9FRj63bMBOm5R7OukmMbTQ-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2022-02-09 19:56 ` Mathieu Desnoyers
2022-02-09 20:17 ` Waiman Long
2022-02-10 0:27 ` Namhyung Kim
2022-02-10 2:12 ` Waiman Long
2022-02-10 9:33 ` Peter Zijlstra
2022-02-10 0:32 ` Namhyung Kim
[not found] ` <CAM9d7cgq+jxu6FJuKhZkprn7dO4DiG5pDjmYZzneQYTfKOM85g-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org>
2022-02-10 9:13 ` Peter Zijlstra
[not found] ` <YgTXUQ9CBoo3+A+c-Nxj+rRp3nVydTX5a5knrm8zTDFooKrT+cvkQGrU6aU0@public.gmane.org>
2022-02-10 19:14 ` Paul E. McKenney
2022-02-10 19:27 ` Waiman Long
[not found] ` <52de2e14-33d9-bdda-4b37-3e72ae9954c7-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
2022-02-10 20:10 ` Paul E. McKenney
2022-02-11 5:57 ` Namhyung Kim
2022-02-11 5:55 ` Namhyung Kim
2022-02-11 10:39 ` Peter Zijlstra
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