From: Uladzislau Rezki <urezki@gmail.com>
To: "Paul E. McKenney" <paulmck@kernel.org>
Cc: Uladzislau Rezki <urezki@gmail.com>, RCU <rcu@vger.kernel.org>,
Neeraj upadhyay <Neeraj.Upadhyay@amd.com>,
Boqun Feng <boqun.feng@gmail.com>,
Hillf Danton <hdanton@sina.com>,
Joel Fernandes <joel@joelfernandes.org>,
LKML <linux-kernel@vger.kernel.org>,
Oleksiy Avramchenko <oleksiy.avramchenko@sony.com>,
Frederic Weisbecker <frederic@kernel.org>
Subject: Re: [PATCH v4 0/4] Reduce synchronize_rcu() latency(v4)
Date: Mon, 29 Jan 2024 21:36:40 +0100 [thread overview]
Message-ID: <ZbgMWGmG3g-IvOw6@pc636> (raw)
In-Reply-To: <adb813a3-e24e-4fb3-b1cf-fad5a571fe9a@paulmck-laptop>
On Mon, Jan 29, 2024 at 11:43:43AM -0800, Paul E. McKenney wrote:
> On Mon, Jan 29, 2024 at 05:23:01PM +0100, Uladzislau Rezki wrote:
> > On Fri, Jan 26, 2024 at 11:07:18PM -0800, Paul E. McKenney wrote:
> > > On Thu, Jan 04, 2024 at 05:25:06PM +0100, Uladzislau Rezki (Sony) wrote:
> > > > This is a v4 that tends to improve synchronize_rcu() call. To be more
> > > > specific it is about reducing a waiting time(especially worst cases)
> > > > of caller that blocks until a grace period is elapsed.
> > > >
> > > > In general, this series separates synchronize_rcu() callers from other
> > > > callbacks. We keep a dedicated an independent queue, thus the processing
> > > > of it starts as soon as grace period is over, so there is no need to wait
> > > > until other callbacks are processed one by one. Please note, a number of
> > > > callbacks can be 10K, 20K, 60K and so on. That is why this series maintain
> > > > a separate track for this call that blocks a context.
> > >
> > > And before I forget (again), a possible follow-on to this work is to
> > > reduce cond_synchronize_rcu() and cond_synchronize_rcu_full() latency.
> > > Right now, these wait for a full additional grace period (and maybe
> > > more) when the required grace period has not elapsed. In contrast,
> > > this work might enable waiting only for the needed portion of a grace
> > > period to elapse.
> > >
> > Thanks. I see it. Probably we also need to move "sync" related
> > functionality out of tree.c file to the sync.c or something similar
> > to that name. IMO.
>
> I would prioritize moving the kfree_rcu() code out of tree.c quite
> a ways over moving out the synchronous-wait code. ;-)
>
Indeed. But i am not about priority :)
--
Uladzislau Rezki
prev parent reply other threads:[~2024-01-29 20:36 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-04 16:25 [PATCH v4 0/4] Reduce synchronize_rcu() latency(v4) Uladzislau Rezki (Sony)
2024-01-04 16:25 ` [PATCH v4 1/4] rcu: Reduce synchronize_rcu() latency Uladzislau Rezki (Sony)
2024-01-09 19:16 ` Kalesh Singh
2024-01-10 9:21 ` Uladzislau Rezki
2024-01-11 16:37 ` Kalesh Singh
2024-01-11 17:35 ` Uladzislau Rezki
2024-01-12 23:09 ` Frederic Weisbecker
2024-01-18 10:37 ` Uladzislau Rezki
2024-01-16 16:18 ` Paul E. McKenney
2024-01-17 12:26 ` Uladzislau Rezki
2024-01-19 15:24 ` Paul E. McKenney
2024-01-22 17:35 ` Uladzislau Rezki
2024-01-23 11:21 ` Paul E. McKenney
2024-01-04 16:25 ` [PATCH v4 2/4] rcu: Add a trace event for synchronize_rcu_normal() Uladzislau Rezki (Sony)
2024-01-12 23:20 ` Frederic Weisbecker
2024-01-15 12:14 ` Uladzislau Rezki
2024-01-04 16:25 ` [PATCH v4 3/4] rcu: Improve handling of synchronize_rcu() users Uladzislau Rezki (Sony)
2024-01-16 16:32 ` Paul E. McKenney
2024-01-04 16:25 ` [PATCH v4 4/4] rcu: Support direct wake-up " Uladzislau Rezki (Sony)
2024-01-13 9:19 ` Z qiang
2024-01-15 10:46 ` Uladzislau Rezki
2024-01-15 10:57 ` Uladzislau Rezki
2024-01-16 6:19 ` Z qiang
2024-01-27 7:07 ` [PATCH v4 0/4] Reduce synchronize_rcu() latency(v4) Paul E. McKenney
2024-01-29 16:23 ` Uladzislau Rezki
2024-01-29 19:43 ` Paul E. McKenney
2024-01-29 20:36 ` Uladzislau Rezki [this message]
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