From: "Paul E. McKenney" <paulmck@kernel.org>
To: Yury Norov <yury.norov@gmail.com>
Cc: "Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
"Rasmus Villemoes" <linux@rasmusvillemoes.dk>,
"Andrew Morton" <akpm@linux-foundation.org>,
"Michał Mirosław" <mirq-linux@rere.qmqm.pl>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Peter Zijlstra" <peterz@infradead.org>,
"David Laight" <David.Laight@aculab.com>,
"Joe Perches" <joe@perches.com>,
"Dennis Zhou" <dennis@kernel.org>,
"Emil Renner Berthing" <kernel@esmil.dk>,
"Nicholas Piggin" <npiggin@gmail.com>,
"Matti Vaittinen" <matti.vaittinen@fi.rohmeurope.com>,
"Alexey Klimov" <aklimov@redhat.com>,
linux-kernel@vger.kernel.org,
"Josh Triplett" <josh@joshtriplett.org>,
"Steven Rostedt" <rostedt@goodmis.org>,
"Mathieu Desnoyers" <mathieu.desnoyers@efficios.com>,
"Lai Jiangshan" <jiangshanlai@gmail.com>,
"Joel Fernandes" <joel@joelfernandes.org>,
rcu@vger.kernel.org
Subject: Re: [PATCH 22/54] rcu: replace cpumask_weight with cpumask_empty where appropriate
Date: Sun, 23 Jan 2022 16:07:34 -0800 [thread overview]
Message-ID: <20220124000734.GB4285@paulmck-ThinkPad-P17-Gen-1> (raw)
In-Reply-To: <20220123183925.1052919-23-yury.norov@gmail.com>
On Sun, Jan 23, 2022 at 10:38:53AM -0800, Yury Norov wrote:
> In some places, RCU code calls cpumask_weight() to check if any bit of a
> given cpumask is set. We can do it more efficiently with cpumask_empty()
> because cpumask_empty() stops traversing the cpumask as soon as it finds
> first set bit, while cpumask_weight() counts all bits unconditionally.
>
> Signed-off-by: Yury Norov <yury.norov@gmail.com>
Good point! Queued and pushed, thank you!
Thanx, Paul
> ---
> kernel/rcu/tree_nocb.h | 4 ++--
> kernel/rcu/tree_plugin.h | 2 +-
> 2 files changed, 3 insertions(+), 3 deletions(-)
>
> diff --git a/kernel/rcu/tree_nocb.h b/kernel/rcu/tree_nocb.h
> index eeafb546a7a0..f83c7b1d6110 100644
> --- a/kernel/rcu/tree_nocb.h
> +++ b/kernel/rcu/tree_nocb.h
> @@ -1169,7 +1169,7 @@ void __init rcu_init_nohz(void)
> struct rcu_data *rdp;
>
> #if defined(CONFIG_NO_HZ_FULL)
> - if (tick_nohz_full_running && cpumask_weight(tick_nohz_full_mask))
> + if (tick_nohz_full_running && !cpumask_empty(tick_nohz_full_mask))
> need_rcu_nocb_mask = true;
> #endif /* #if defined(CONFIG_NO_HZ_FULL) */
>
> @@ -1348,7 +1348,7 @@ static void __init rcu_organize_nocb_kthreads(void)
> */
> void rcu_bind_current_to_nocb(void)
> {
> - if (cpumask_available(rcu_nocb_mask) && cpumask_weight(rcu_nocb_mask))
> + if (cpumask_available(rcu_nocb_mask) && !cpumask_empty(rcu_nocb_mask))
> WARN_ON(sched_setaffinity(current->pid, rcu_nocb_mask));
> }
> EXPORT_SYMBOL_GPL(rcu_bind_current_to_nocb);
> diff --git a/kernel/rcu/tree_plugin.h b/kernel/rcu/tree_plugin.h
> index c5b45c2f68a1..0dc0c8d6717c 100644
> --- a/kernel/rcu/tree_plugin.h
> +++ b/kernel/rcu/tree_plugin.h
> @@ -1215,7 +1215,7 @@ static void rcu_boost_kthread_setaffinity(struct rcu_node *rnp, int outgoingcpu)
> cpu != outgoingcpu)
> cpumask_set_cpu(cpu, cm);
> cpumask_and(cm, cm, housekeeping_cpumask(HK_FLAG_RCU));
> - if (cpumask_weight(cm) == 0)
> + if (cpumask_empty(cm))
> cpumask_copy(cm, housekeeping_cpumask(HK_FLAG_RCU));
> set_cpus_allowed_ptr(t, cm);
> free_cpumask_var(cm);
> --
> 2.30.2
>
next prev parent reply other threads:[~2022-01-24 0:07 UTC|newest]
Thread overview: 97+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-01-23 18:38 [PATCH v3 00/54] lib/bitmap: optimize bitmap_weight() usage Yury Norov
2022-01-23 18:38 ` [PATCH 01/54] net/dsa: don't use bitmap_weight() in b53_arl_read() Yury Norov
2022-01-24 3:11 ` Florian Fainelli
2022-01-23 18:38 ` [PATCH 02/54] net/ethernet: don't use bitmap_weight() in bcm_sysport_rule_set() Yury Norov
2022-01-24 3:11 ` Florian Fainelli
2022-01-23 18:38 ` [PATCH 03/54] thermal/intel: don't use bitmap_weight() in end_power_clamp() Yury Norov
2022-02-04 18:29 ` Rafael J. Wysocki
2022-01-23 18:38 ` [PATCH 04/54] net: mellanox: fix open-coded for_each_set_bit() Yury Norov
2022-01-26 9:01 ` Tariq Toukan
2022-01-23 18:38 ` [PATCH 05/54] nds32: perf: replace bitmap_weight with bitmap_empty where appropriate Yury Norov
2022-01-23 18:38 ` [PATCH 06/54] x86/kvm: " Yury Norov
2022-01-24 9:11 ` Vitaly Kuznetsov
2022-01-23 18:38 ` [PATCH 07/54] gpu: drm: " Yury Norov
2022-01-23 18:38 ` [PATCH 08/54] net: ethernet: replace bitmap_weight with bitmap_empty for intel Yury Norov
2022-01-23 18:38 ` [PATCH 09/54] net: ethernet: replace bitmap_weight with bitmap_empty for Marvell Yury Norov
2022-01-23 18:38 ` [PATCH 10/54] net: ethernet: replace bitmap_weight with bitmap_empty for qlogic Yury Norov
2022-01-24 12:28 ` Andy Shevchenko
2022-01-25 21:09 ` Yury Norov
2022-01-25 22:14 ` David Laight
2022-01-25 23:10 ` Yury Norov
2022-01-23 18:38 ` [PATCH 11/54] perf: replace bitmap_weight with bitmap_empty where appropriate Yury Norov
2022-01-23 18:38 ` [PATCH 12/54] tools/perf: " Yury Norov
2022-02-15 14:34 ` Arnaldo Carvalho de Melo
2022-01-23 18:38 ` [PATCH 13/54] arch/alpha: replace cpumask_weight with cpumask_empty " Yury Norov
2022-01-23 18:38 ` [PATCH 14/54] arch/ia64: " Yury Norov
2022-01-23 18:38 ` [PATCH 15/54] arch/x86: " Yury Norov
2022-01-27 17:20 ` Steve Wahl
2022-01-23 18:38 ` [PATCH 16/54] cpufreq: " Yury Norov
2022-01-24 10:41 ` Sudeep Holla
2022-02-09 6:15 ` Viresh Kumar
2022-01-23 18:38 ` [PATCH 17/54] gpu: drm: " Yury Norov
2022-01-25 9:28 ` Tvrtko Ursulin
2022-01-25 18:16 ` Yury Norov
2022-01-26 9:43 ` Tvrtko Ursulin
2022-01-23 18:38 ` [PATCH 18/54] drivers/infiniband: " Yury Norov
2022-01-23 19:13 ` Leon Romanovsky
2022-01-23 18:38 ` [PATCH 19/54] drivers/irqchip: " Yury Norov
2022-01-24 3:11 ` Florian Fainelli
2022-01-23 18:38 ` [PATCH 20/54] kernel/irq: " Yury Norov
2022-01-23 18:38 ` [PATCH 21/54] kernel: replace cpumask_weight with cpumask_empty in padata.c Yury Norov
2022-01-28 6:29 ` Herbert Xu
2022-01-23 18:38 ` [PATCH 22/54] rcu: replace cpumask_weight with cpumask_empty where appropriate Yury Norov
2022-01-24 0:07 ` Paul E. McKenney [this message]
2022-01-23 18:38 ` [PATCH 23/54] sched: " Yury Norov
2022-01-23 18:38 ` [PATCH 24/54] time: replace cpumask_weight with cpumask_empty in clocksource.c Yury Norov
2022-01-23 18:38 ` [PATCH 25/54] mm/vmstat: replace cpumask_weight with cpumask_empty where appropriate Yury Norov
2022-01-23 18:38 ` [PATCH 26/54] arch/x86: replace nodes_weight with nodes_empty " Yury Norov
2022-01-23 18:38 ` [PATCH 27/54] lib/bitmap: add bitmap_weight_{cmp, eq, gt, ge, lt, le} functions Yury Norov
2022-01-24 12:41 ` Andy Shevchenko
2022-01-24 12:43 ` Andy Shevchenko
2022-01-24 12:49 ` Peter Zijlstra
2022-01-26 15:56 ` Yury Norov
2022-01-28 6:59 ` Vaittinen, Matti
2022-01-23 18:38 ` [PATCH 28/54] arch/x86: replace bitmap_weight with bitmap_weight_{eq,gt,ge,lt,le} where appropriate Yury Norov
2022-01-23 18:39 ` [PATCH 29/54] drivers/iio: replace bitmap_weight() with bitmap_weight_{eq,gt} " Yury Norov
2022-01-24 12:46 ` Andy Shevchenko
2022-01-30 12:54 ` Jonathan Cameron
2022-01-23 18:39 ` [PATCH 30/54] drivers/memstick: replace bitmap_weight with bitmap_weight_eq " Yury Norov
2022-01-31 16:07 ` Ulf Hansson
2022-01-23 18:39 ` [PATCH 31/54] net: ethernet: replace bitmap_weight with bitmap_weight_eq for intel Yury Norov
2022-01-23 18:39 ` [PATCH 32/54] net: ethernet: replace bitmap_weight with bitmap_weight_{eq,gt} for OcteonTX2 Yury Norov
2022-01-23 18:39 ` [PATCH 33/54] net: ethernet: replace bitmap_weight with bitmap_weight_{eq,gt,ge,lt,le} for mellanox Yury Norov
2022-01-24 12:48 ` Andy Shevchenko
2022-02-09 6:46 ` Yury Norov
2022-01-23 18:39 ` [PATCH 34/54] perf: replace bitmap_weight with bitmap_weight_eq for ThunderX2 Yury Norov
2022-01-23 18:39 ` [PATCH 35/54] drivers/staging: replace bitmap_weight with bitmap_weight_le for tegra-video Yury Norov
2022-01-23 18:39 ` [PATCH 36/54] lib/cpumask: add cpumask_weight_{eq,gt,ge,lt,le} Yury Norov
2022-01-23 18:39 ` [PATCH 37/54] arch/ia64: replace cpumask_weight with cpumask_weight_eq in mm/tlb.c Yury Norov
2022-01-23 18:39 ` [PATCH 38/54] arch/mips: replace cpumask_weight with cpumask_weight_{eq, ...} where appropriate Yury Norov
2022-01-25 19:05 ` Thomas Bogendoerfer
2022-01-23 18:39 ` [PATCH 39/54] arch/powerpc: " Yury Norov
2022-01-23 18:39 ` [PATCH 40/54] arch/s390: replace cpumask_weight with cpumask_weight_eq " Yury Norov
2022-01-23 18:39 ` [PATCH 41/54] arch/x86: " Yury Norov
2022-01-24 8:05 ` Peter Zijlstra
2022-01-24 9:16 ` Vitaly Kuznetsov
2022-01-23 18:39 ` [PATCH 42/54] firmware: pcsi: replace cpumask_weight with cpumask_weight_eq Yury Norov
2022-01-23 18:39 ` [PATCH 43/54] drivers/hv: " Yury Norov
2022-01-23 22:00 ` Wei Liu
2022-01-23 22:02 ` Haiyang Zhang
2022-01-24 9:20 ` Vitaly Kuznetsov
2022-01-27 15:02 ` Michael Kelley (LINUX)
2022-01-28 9:31 ` Vitaly Kuznetsov
2022-01-23 18:39 ` [PATCH 44/54] infiniband: replace cpumask_weight with cpumask_weight_{eq, ...} where appropriate Yury Norov
2022-01-23 18:39 ` [PATCH 45/54] scsi: replace cpumask_weight with cpumask_weight_gt Yury Norov
2022-01-23 18:39 ` [PATCH 46/54] soc: replace cpumask_weight with cpumask_weight_lt Yury Norov
2022-01-23 18:39 ` [PATCH 47/54] sched: replace cpumask_weight with cpumask_weight_eq where appropriate Yury Norov
2022-01-24 8:05 ` Peter Zijlstra
2022-01-23 18:39 ` [PATCH 48/54] kernel/time: " Yury Norov
2022-01-24 8:06 ` Peter Zijlstra
2022-01-23 18:39 ` [PATCH 49/54] lib/nodemask: add nodemask_weight_{eq,gt,ge,lt,le} Yury Norov
2022-01-23 18:39 ` [PATCH 50/54] acpi: replace nodes__weight with nodes_weight_ge for numa Yury Norov
2022-01-23 18:39 ` [PATCH 51/54] mm: replace nodes_weight with nodes_weight_eq in mempolicy Yury Norov
2022-01-23 18:39 ` [PATCH 52/54] lib/nodemask: add num_node_state_eq() Yury Norov
2022-01-23 18:39 ` [PATCH 53/54] tools/bitmap: sync bitmap_weight Yury Norov
2022-01-23 18:39 ` [PATCH 54/54] MAINTAINERS: add cpumask and nodemask files to BITMAP_API Yury Norov
2022-01-26 7:30 ` [PATCH v3 00/54] lib/bitmap: optimize bitmap_weight() usage Vaittinen, Matti
2022-01-27 17:44 ` Yury Norov
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