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From: Frederic Weisbecker <frederic@kernel.org>
To: Joel Fernandes <joel@joelfernandes.org>
Cc: linux-kernel@vger.kernel.org, Qiuxu Zhuo <qiuxu.zhuo@intel.com>,
	Lai Jiangshan <jiangshanlai@gmail.com>,
	linux-doc@vger.kernel.org,
	"Paul E. McKenney" <paulmck@kernel.org>,
	rcu@vger.kernel.org, urezki@gmail.com
Subject: Re: [PATCH v3] rcu: Add a minimum time for marking boot as completed
Date: Wed, 8 Mar 2023 16:01:12 +0100	[thread overview]
Message-ID: <ZAijOO0vEiiDn+Ex@lothringen> (raw)
In-Reply-To: <FF43EB74-026D-4863-8926-8DB40FED5930@joelfernandes.org>

On Wed, Mar 08, 2023 at 05:52:50AM -0800, Joel Fernandes wrote:
> Just to add to previous reply:
> 
> One thing to consider is that it is more of a performance improvement for
> booting in expedited mode to fallback to normal later, than a bug
> fix. Repeated synchronize_rcu() can easily add 100s of milliseconds and to
> remedy that — a conversion of the call from normal API to the expedited API
> will not help.

2 things to consider:

1) Is it this about specific calls to synchronize_rcu() that repeat a lot
   and thus create such measurable impact? If so the specific callsites should
   be considered for a conversion.

2) Is it about lots of different calls to synchronize_rcu() that gather a big
   noise? Then the solution is different.

Again without proper analysis, what do we know?

Thanks.

  reply	other threads:[~2023-03-08 15:01 UTC|newest]

Thread overview: 55+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2023-03-03 21:38 [PATCH v3] rcu: Add a minimum time for marking boot as completed Joel Fernandes (Google)
2023-03-04  1:02 ` Paul E. McKenney
2023-03-04  4:51   ` Joel Fernandes
2023-03-11 20:44     ` Paul E. McKenney
2023-03-11 22:23       ` Joel Fernandes
2023-03-11 22:57         ` Paul E. McKenney
2023-03-06  8:24   ` Zhuo, Qiuxu
2023-03-06 14:49     ` Paul E. McKenney
2023-03-07  7:49       ` Zhuo, Qiuxu
2023-03-07 15:22         ` Paul E. McKenney
2023-03-09 15:17           ` Zhuo, Qiuxu
2023-03-09 21:53             ` Paul E. McKenney
2023-03-10  0:11               ` Akira Yokosawa
2023-03-10  1:47                 ` Paul E. McKenney
2023-03-10  2:35                 ` Zhuo, Qiuxu
2023-03-05 11:39 ` Uladzislau Rezki
2023-03-05 15:03   ` Joel Fernandes
2023-03-06  8:37     ` Zhuo, Qiuxu
2023-03-05 20:34   ` Paul E. McKenney
2023-03-07 13:01 ` Frederic Weisbecker
2023-03-07 13:40   ` Uladzislau Rezki
2023-03-07 13:48     ` Joel Fernandes
2023-03-07 17:33       ` Paul E. McKenney
2023-03-07 18:54         ` Joel Fernandes
2023-03-07 19:27           ` Paul E. McKenney
2023-03-08  9:41             ` Uladzislau Rezki
2023-03-08 14:45               ` Paul E. McKenney
2023-03-09 12:57                 ` Uladzislau Rezki
2023-03-09 22:10                   ` Joel Fernandes
2023-03-10  8:55                     ` Uladzislau Rezki
2023-03-11  6:24                       ` Paul E. McKenney
2023-03-11 17:19                         ` Joel Fernandes
2023-03-13  9:51                         ` Uladzislau Rezki
2023-03-13 12:27                           ` Uladzislau Rezki
2023-03-13 13:48                             ` Zhuo, Qiuxu
2023-03-13 15:28                               ` Uladzislau Rezki
2023-03-13 13:58                           ` Joel Fernandes
2023-03-13 15:32                             ` Uladzislau Rezki
2023-03-13 15:49                               ` Joel Fernandes
2023-03-13 18:12                                 ` Uladzislau Rezki
2023-03-13 18:56                                   ` Paul E. McKenney
2023-03-14 11:16                                     ` Uladzislau Rezki
2023-03-14 13:49                                       ` Paul E. McKenney
2023-03-14 22:44                               ` Joel Fernandes
2023-03-15 17:12                                 ` Uladzislau Rezki
2023-03-15 12:21                       ` Joel Fernandes
2023-03-15 16:12                         ` Paul E. McKenney
2023-03-08 10:14       ` Uladzislau Rezki
2023-03-15 12:18         ` Joel Fernandes
2023-03-07 13:41   ` Joel Fernandes
2023-03-07 17:19     ` Frederic Weisbecker
2023-03-07 18:19       ` Joel Fernandes
2023-03-08 13:52       ` Joel Fernandes
2023-03-08 15:01         ` Frederic Weisbecker [this message]
2023-03-08 15:09           ` Joel Fernandes

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