From: Joel Fernandes <joel@joelfernandes.org>
To: Uladzislau Rezki <urezki@gmail.com>
Cc: rcu@vger.kernel.org, linux-kernel@vger.kernel.org,
rushikesh.s.kadam@intel.com, neeraj.iitr10@gmail.com,
frederic@kernel.org, paulmck@kernel.org, rostedt@goodmis.org
Subject: Re: [PATCH v6 1/4] rcu: Make call_rcu() lazy to save power
Date: Tue, 27 Sep 2022 15:14:14 +0000 [thread overview]
Message-ID: <YzMTRrMKCnEMl/ov@google.com> (raw)
In-Reply-To: <YzMP4LaIUY8Dh9Nw@pc636>
On Tue, Sep 27, 2022 at 04:59:44PM +0200, Uladzislau Rezki wrote:
[...]
> > > systemd-udevd-642 [050] ..... 17.349832: __call_rcu_common: -> ____fput+0x0/0x10: task_work_run+0x5c/0x90 <- 0x0
> > > systemd-udevd-665 [061] ..... 17.349834: __call_rcu_common: -> ____fput+0x0/0x10: task_work_run+0x5c/0x90 <- 0x0
> > > systemd-udevd-675 [012] ..... 17.349835: __call_rcu_common: -> ____fput+0x0/0x10: task_work_run+0x5c/0x90 <- 0x0
> > > systemd-udevd-675 [012] ..... 17.349853: __call_rcu_common: -> ____fput+0x0/0x10: task_work_run+0x5c/0x90 <- 0x0
> > > systemd-udevd-642 [050] ..... 17.349861: __call_rcu_common: -> 0x0: __dentry_kill+0x140/0x180 <- 0x2
> > > systemd-udevd-675 [012] ..... 17.349873: __call_rcu_common: -> ____fput+0x0/0x10: task_work_run+0x5c/0x90 <- 0x0
> > > systemd-udevd-665 [061] ..... 17.349879: __call_rcu_common: -> ____fput+0x0/0x10: task_work_run+0x5c/0x90 <- 0x0
> > > systemd-udevd-665 [061] ..... 17.350007: __call_rcu_common: -> ____fput+0x0/0x10: task_work_run+0x5c/0x90 <- 0x0
> > > systemd-udevd-665 [061] ..... 17.350011: __call_rcu_common: -> ____fput+0x0/0x10: task_work_run+0x5c/0x90 <- 0x0
> > > systemd-udevd-665 [061] ..... 17.350080: __call_rcu_common: -> ____fput+0x0/0x10: task_work_run+0x5c/0x90 <- 0x0
> > > systemd-udevd-665 [061] ..... 17.350175: __call_rcu_common: -> ____fput+0x0/0x10: task_work_run+0x5c/0x90 <- 0x0
> > > systemd-udevd-665 [061] ..... 17.350362: dev_change_name: --> renamed from eth0
> > > <snip>
> > >
> > > First delay:
> > >
> > > <snip>
> > > systemd-udevd-645 [053] ..... 2.339024: __call_rcu_common: -> 0x0: __dentry_kill+0x140/0x180 <- 0x2
> > > kworker/0:3-546 [000] d..1. 6.329516: __call_rcu_common: -> 0x0: queue_rcu_work+0x2b/0x40 <- 0xffff8c70effe40a0
> > > <snip>
> > >
> > > __dentry_kill() function and after 4 seconds there is another one queue_rcu_work().
> > > I have checked the __dentry_kill() if it can do any sync talk with RCU but from the
> > > first glance i do not see anything critical. But more attention is required.
> >
> > Can you log rcu_barrier() as well? It could be that the print is just a side
> > effect of something else that is not being printed.
> >
> It has nothing to do with rcu_barrier() in my case. Also i have checked
> the synchronize_rcu() it also works as expected, i.e. it is not a
> blocking reason.
>
> Have you tried my config?
Yes I am in the process of trying it.
thanks,
- Joel
next prev parent reply other threads:[~2022-09-27 15:14 UTC|newest]
Thread overview: 62+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-09-22 22:01 [PATCH v6 0/4] rcu: call_rcu() power improvements Joel Fernandes (Google)
2022-09-22 22:01 ` [PATCH v6 1/4] rcu: Make call_rcu() lazy to save power Joel Fernandes (Google)
2022-09-23 21:44 ` Paul E. McKenney
2022-09-24 16:20 ` Joel Fernandes
2022-09-24 21:11 ` Paul E. McKenney
2022-09-24 22:56 ` Joel Fernandes
2022-09-25 17:31 ` Joel Fernandes
2022-09-26 17:42 ` Paul E. McKenney
2022-09-26 21:07 ` Joel Fernandes
2022-09-26 22:37 ` Paul E. McKenney
2022-09-26 23:33 ` Joel Fernandes
2022-09-26 23:53 ` Paul E. McKenney
2022-10-03 19:33 ` Joel Fernandes
2022-10-03 19:49 ` Paul E. McKenney
2022-09-24 22:46 ` Frederic Weisbecker
2022-09-24 23:28 ` Joel Fernandes
2022-09-25 1:00 ` Joel Fernandes
2022-09-25 22:00 ` Frederic Weisbecker
2022-09-26 15:04 ` Joel Fernandes
2022-09-26 17:33 ` Paul E. McKenney
2022-09-26 23:37 ` Joel Fernandes
2022-09-25 22:09 ` Frederic Weisbecker
2022-09-26 17:45 ` Paul E. McKenney
2022-09-25 8:57 ` Uladzislau Rezki
2022-09-25 17:46 ` Joel Fernandes
2022-09-26 17:48 ` Paul E. McKenney
2022-09-26 19:32 ` Uladzislau Rezki
2022-09-26 21:02 ` Joel Fernandes
2022-09-26 22:32 ` Paul E. McKenney
2022-09-26 23:47 ` Joel Fernandes
2022-09-26 23:59 ` Paul E. McKenney
2022-09-27 1:49 ` Joel Fernandes
2022-09-27 3:22 ` Paul E. McKenney
2022-09-27 13:05 ` Joel Fernandes
2022-09-27 14:14 ` Paul E. McKenney
2022-09-27 14:22 ` Joel Fernandes
2022-09-27 14:30 ` Paul E. McKenney
2022-09-27 15:25 ` Joel Fernandes
2022-09-27 15:59 ` Paul E. McKenney
[not found] ` <CAEXW_YRpAjvmBPzRA-hRQpuaDuZUzfndLb3q+e3BUyWprg5wkQ@mail.gmail.com>
2022-09-27 3:21 ` Paul E. McKenney
2022-09-26 22:27 ` Paul E. McKenney
2022-09-26 19:39 ` Uladzislau Rezki
2022-09-26 20:54 ` Joel Fernandes
2022-09-26 22:35 ` Paul E. McKenney
2022-09-26 23:44 ` Joel Fernandes
2022-09-26 23:57 ` Paul E. McKenney
2022-09-27 1:16 ` Joel Fernandes
2022-09-27 3:20 ` Paul E. McKenney
2022-09-27 14:08 ` Uladzislau Rezki
2022-09-27 14:30 ` Joel Fernandes
2022-09-27 14:59 ` Uladzislau Rezki
2022-09-27 15:13 ` Uladzislau Rezki
2022-09-27 21:31 ` Uladzislau Rezki
2022-09-27 22:05 ` Joel Fernandes
2022-09-27 22:29 ` Joel Fernandes
2022-09-30 16:11 ` Uladzislau Rezki
2022-10-04 11:35 ` Uladzislau Rezki
2022-10-04 18:06 ` Joel Fernandes
2022-09-27 15:14 ` Joel Fernandes [this message]
2022-09-22 22:01 ` [PATCH v6 2/4] rcu: shrinker for lazy rcu Joel Fernandes (Google)
2022-09-22 22:01 ` [PATCH v6 3/4] rcuscale: Add laziness and kfree tests Joel Fernandes (Google)
2022-09-22 22:01 ` [PATCH v6 4/4] percpu-refcount: Use call_rcu_flush() for atomic switch Joel Fernandes (Google)
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