From: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
To: Leonardo Bras <leobras.c@gmail.com>
Cc: "Jonathan Corbet" <corbet@lwn.net>,
"Shuah Khan" <skhan@linuxfoundation.org>,
"Peter Zijlstra" <peterz@infradead.org>,
"Ingo Molnar" <mingo@redhat.com>, "Will Deacon" <will@kernel.org>,
"Boqun Feng" <boqun@kernel.org>,
"Waiman Long" <longman@redhat.com>,
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"Lorenzo Stoakes" <ljs@kernel.org>,
"Liam R. Howlett" <liam@infradead.org>,
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"David Rientjes" <rientjes@google.com>,
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"Chris Li" <chrisl@kernel.org>,
"Kairui Song" <kasong@tencent.com>,
"Kemeng Shi" <shikemeng@huaweicloud.com>,
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"Qi Zheng" <qi.zheng@linux.dev>,
"Shakeel Butt" <shakeel.butt@linux.dev>,
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"Randy Dunlap" <rdunlap@infradead.org>,
"Thomas Gleixner" <tglx@kernel.org>,
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"Nathan Chancellor" <nathan@kernel.org>,
"Miguel Ojeda" <ojeda@kernel.org>,
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"Douglas Anderson" <dianders@chromium.org>,
"Gary Guo" <gary@garyguo.net>,
"Christian Brauner" <brauner@kernel.org>,
"Pasha Tatashin" <pasha.tatashin@soleen.com>,
"Masahiro Yamada" <masahiroy@kernel.org>,
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linux-mm@kvack.org, linux-rt-devel@lists.linux.dev
Subject: Re: [PATCH v4 0/4] Introduce Per-CPU Work helpers (was QPW)
Date: Tue, 14 Jul 2026 12:12:48 +0200 [thread overview]
Message-ID: <20260714101248.hV06z2cr@linutronix.de> (raw)
In-Reply-To: <alVV44RO_SolaqMW@WindFlash>
On 2026-07-13 18:17:23 [-0300], Leonardo Bras wrote:
> IIRC there are multiple users of this mechanism around the kernel. I
> remember picking the first three (swap, slub and memcontrol) as examples of
> how to use pwlocks (QPW at the time). With the concept proven, I could then
> proceed to work with other potential users to replace it. (We ended up
> dropping memcontrol in the process)
>
> The main idea is to replace as many potential users as possible to reduce
> as much as possible the amount of IPIs in isolated cpus, and allow Linux
> to run workloads which require much lower latency.
Right. I am not entirely opposed to this idea. If you can't improve the
situation by other means I would consider this as the last resort. If
the mm folks are on board with this, then even better.
> This idea came as a general solution to a bunch of latency violations
> Marcelo and I were coming across.
>
> Thanks!
> Leo
Sebastian
prev parent reply other threads:[~2026-07-14 10:12 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-05-19 1:27 [PATCH v4 0/4] Introduce Per-CPU Work helpers (was QPW) Leonardo Bras
2026-05-19 1:27 ` [PATCH v4 1/4] Introducing pw_lock() and per-cpu queue & flush work Leonardo Bras
2026-05-20 10:08 ` Frederic Weisbecker
2026-07-12 20:49 ` Leonardo Bras
2026-05-20 13:48 ` Sebastian Andrzej Siewior
2026-05-20 14:47 ` Frederic Weisbecker
2026-07-12 21:17 ` Leonardo Bras
2026-07-12 21:17 ` Leonardo Bras
2026-05-20 22:06 ` Randy Dunlap
2026-07-12 21:23 ` Leonardo Bras
2026-05-26 19:15 ` Jonathan Corbet
2026-07-12 21:32 ` Leonardo Bras
2026-05-19 1:27 ` [PATCH v4 2/4] mm/swap: move bh draining into a separate workqueue Leonardo Bras
2026-05-19 1:27 ` [PATCH v4 3/4] swap: apply new pw_queue_on() interface Leonardo Bras
2026-05-20 15:07 ` Sebastian Andrzej Siewior
2026-07-12 21:43 ` Leonardo Bras
2026-07-13 7:31 ` Sebastian Andrzej Siewior
2026-07-13 21:28 ` Leonardo Bras
2026-05-19 1:27 ` [PATCH v4 4/4] slub: " Leonardo Bras
2026-05-19 10:21 ` kernel test robot
2026-05-20 14:53 ` Sebastian Andrzej Siewior
2026-07-12 22:35 ` Leonardo Bras
2026-07-13 7:36 ` Sebastian Andrzej Siewior
2026-07-13 10:55 ` Vlastimil Babka (SUSE)
2026-07-13 21:44 ` Leonardo Bras
2026-07-13 21:40 ` Leonardo Bras
2026-07-14 9:47 ` Sebastian Andrzej Siewior
2026-05-19 6:58 ` [syzbot ci] Re: Introduce Per-CPU Work helpers (was QPW) syzbot ci
2026-05-20 13:09 ` [PATCH v4 0/4] " Sebastian Andrzej Siewior
2026-07-12 20:32 ` Leonardo Bras
2026-07-13 8:07 ` Sebastian Andrzej Siewior
2026-07-13 21:17 ` Leonardo Bras
2026-07-14 10:12 ` Sebastian Andrzej Siewior [this message]
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