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From: Joel Fernandes <joelaf@google.com>
To: rcu@vger.kernel.org,
	"Cc: Frederic Weisbecker" <fweisbec@gmail.com>,
	 "Paul E. McKenney" <paulmck@kernel.org>
Subject: Observation on NOHZ_FULL
Date: Mon, 29 Jan 2024 17:47:39 +0000	[thread overview]
Message-ID: <CAJWu+oo8w6zc=m7f9vkz66xYZnoCqs1FrgmLtcWxEpE5QCJgig@mail.gmail.com> (raw)

Hi Guys,
Something caught my eye in [1] which a colleague pointed me to
 - CONFIG_HZ=1000 : 14866.05 bogo ops/s
 - CONFIG_HZ=1000+nohz_full : 18505.52 bogo ops/s

The test in concern is:
stress-ng --matrix $(getconf _NPROCESSORS_ONLN) --timeout 5m --metrics-brief

which is a CPU intensive test.

Any thoughts on what else can attribute a 30% performance increase
versus non-nohz_full ? (Confession: No idea if the baseline is
nohz_idle or no nohz at all). If it is 30%, I may want to evaluate
nohz_full on some of our limited-CPU devices :)

Cheers,

 - Joel

[1] https://bugs.launchpad.net/ubuntu/+source/linux/+bug/2051342

             reply	other threads:[~2024-01-29 17:47 UTC|newest]

Thread overview: 35+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2024-01-29 17:47 Joel Fernandes [this message]
2024-01-29 20:41 ` Observation on NOHZ_FULL Paul E. McKenney
2024-01-29 22:16   ` Joel Fernandes
2024-01-30  6:58     ` Andrea Righi
2024-01-30 10:17       ` Paul E. McKenney
2024-01-30 11:06         ` Uladzislau Rezki
2024-01-30 11:27           ` Andrea Righi
2024-01-30 11:41             ` Uladzislau Rezki
2024-01-30 13:39             ` Paul E. McKenney
2024-02-06 17:51               ` Andrea Righi
2024-02-06 18:44                 ` Paul E. McKenney
2024-02-07 13:04                   ` Uladzislau Rezki
2024-02-07 15:12                     ` Andrea Righi
2024-02-07 15:49                       ` Joel Fernandes
2024-02-15  7:51                   ` Andrea Righi
2024-02-15 13:15                     ` Uladzislau Rezki
2024-02-15 14:02                       ` Joel Fernandes
2024-02-07 15:48                 ` Joel Fernandes
2024-02-07 16:31                   ` Andrea Righi
2024-02-07 16:52                     ` Joel Fernandes
2024-02-07 17:05                       ` Andrea Righi
2024-02-08  5:54                         ` Joel Fernandes
2024-02-08  6:55                           ` Andrea Righi
2024-02-08 12:53                             ` Uladzislau Rezki
2024-02-08 14:51                               ` Uladzislau Rezki
2024-02-12  0:22                                 ` Joel Fernandes
2024-02-12  9:05                                   ` Uladzislau Rezki
2024-02-12  9:44                                   ` Uladzislau Rezki
2024-01-29 20:48 ` Uladzislau Rezki
2024-01-29 22:20   ` Joel Fernandes
2024-01-29 22:43     ` Frederic Weisbecker
2024-01-29 22:53       ` Joel Fernandes
2024-01-29 23:11         ` Frederic Weisbecker
2024-01-29 23:36           ` Joel Fernandes
2024-01-30  0:40       ` Paul E. McKenney

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