From: Peter Zijlstra <peterz@infradead.org>
To: Dmitry Ilvokhin <d@ilvokhin.com>
Cc: Ingo Molnar <mingo@redhat.com>, Will Deacon <will@kernel.org>,
Boqun Feng <boqun@kernel.org>, Waiman Long <longman@redhat.com>,
Thomas Bogendoerfer <tsbogend@alpha.franken.de>,
Juergen Gross <jgross@suse.com>,
Ajay Kaher <ajay.kaher@broadcom.com>,
Alexey Makhalov <alexey.makhalov@broadcom.com>,
Broadcom internal kernel review list
<bcm-kernel-feedback-list@broadcom.com>,
Thomas Gleixner <tglx@kernel.org>, Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
x86@kernel.org, "H. Peter Anvin" <hpa@zytor.com>,
Arnd Bergmann <arnd@arndb.de>, Dennis Zhou <dennis@kernel.org>,
Tejun Heo <tj@kernel.org>, Christoph Lameter <cl@gentwo.org>,
Steven Rostedt <rostedt@goodmis.org>,
Masami Hiramatsu <mhiramat@kernel.org>,
Mathieu Desnoyers <mathieu.desnoyers@efficios.com>,
linux-kernel@vger.kernel.org, linux-mips@vger.kernel.org,
virtualization@lists.linux.dev, linux-arch@vger.kernel.org,
linux-mm@kvack.org, linux-trace-kernel@vger.kernel.org,
kernel-team@meta.com
Subject: Re: [PATCH v6 0/7] locking: contended_release tracepoint instrumentation
Date: Wed, 13 May 2026 21:26:05 +0200 [thread overview]
Message-ID: <20260513192605.GA2545104@noisy.programming.kicks-ass.net> (raw)
In-Reply-To: <cover.1777999826.git.d@ilvokhin.com>
On Tue, May 05, 2026 at 05:09:29PM +0000, Dmitry Ilvokhin wrote:
> This series adds a contended_release tracepoint that fires on the
> holder side when a lock with waiters is released. This provides:
>
> - Hold time estimation: when the holder's own acquisition was
> contended, its contention_end (acquisition) and contended_release
> can be correlated to measure how long the lock was held under
> contention.
>
> - The holder's stack at release time, which may differ from what perf lock
> contention --lock-owner captures if the holder does significant work between
> the waiter's arrival and the unlock.
>
> Note: for reader/writer locks, the tracepoint fires for every reader
> releasing while a writer is waiting, not only for the last reader.
And for qspinlock.
I am really not sure this is worth the overhead for qspinlock / rwlock.
prev parent reply other threads:[~2026-05-13 19:26 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-05 17:09 [PATCH v6 0/7] locking: contended_release tracepoint instrumentation Dmitry Ilvokhin
2026-05-05 17:09 ` [PATCH v6 1/7] tracing/lock: Remove unnecessary linux/sched.h include Dmitry Ilvokhin
2026-05-05 17:09 ` [PATCH v6 2/7] locking/percpu-rwsem: Extract __percpu_up_read() Dmitry Ilvokhin
2026-05-05 17:09 ` [PATCH v6 3/7] locking: Add contended_release tracepoint to sleepable locks Dmitry Ilvokhin
2026-05-05 17:09 ` [PATCH v6 4/7] locking: Factor out queued_spin_release() Dmitry Ilvokhin
2026-05-13 15:37 ` Steven Rostedt
2026-05-05 17:09 ` [PATCH v6 5/7] locking: Add contended_release tracepoint to qspinlock Dmitry Ilvokhin
2026-05-13 15:41 ` Steven Rostedt
2026-05-14 14:13 ` Dmitry Ilvokhin
2026-05-14 16:03 ` Steven Rostedt
2026-05-15 14:40 ` Dmitry Ilvokhin
2026-05-13 19:33 ` Peter Zijlstra
2026-05-14 12:34 ` Dmitry Ilvokhin
2026-05-05 17:09 ` [PATCH v6 6/7] locking: Factor out __queued_read_unlock()/__queued_write_unlock() Dmitry Ilvokhin
2026-05-13 15:41 ` Steven Rostedt
2026-05-05 17:09 ` [PATCH v6 7/7] locking: Add contended_release tracepoint to qrwlock Dmitry Ilvokhin
2026-05-13 15:43 ` Steven Rostedt
2026-05-13 19:26 ` Peter Zijlstra [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260513192605.GA2545104@noisy.programming.kicks-ass.net \
--to=peterz@infradead.org \
--cc=ajay.kaher@broadcom.com \
--cc=alexey.makhalov@broadcom.com \
--cc=arnd@arndb.de \
--cc=bcm-kernel-feedback-list@broadcom.com \
--cc=boqun@kernel.org \
--cc=bp@alien8.de \
--cc=cl@gentwo.org \
--cc=d@ilvokhin.com \
--cc=dave.hansen@linux.intel.com \
--cc=dennis@kernel.org \
--cc=hpa@zytor.com \
--cc=jgross@suse.com \
--cc=kernel-team@meta.com \
--cc=linux-arch@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mips@vger.kernel.org \
--cc=linux-mm@kvack.org \
--cc=linux-trace-kernel@vger.kernel.org \
--cc=longman@redhat.com \
--cc=mathieu.desnoyers@efficios.com \
--cc=mhiramat@kernel.org \
--cc=mingo@redhat.com \
--cc=rostedt@goodmis.org \
--cc=tglx@kernel.org \
--cc=tj@kernel.org \
--cc=tsbogend@alpha.franken.de \
--cc=virtualization@lists.linux.dev \
--cc=will@kernel.org \
--cc=x86@kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.