From: Yury Norov <yury.norov@gmail.com>
To: "Andy Shevchenko" <andriy.shevchenko@linux.intel.com>,
"David Laight" <David.Laight@ACULAB.COM>,
"Greg Kroah-Hartman" <gregkh@linuxfoundation.org>,
"Joe Perches" <joe@perches.com>,
"Julia Lawall" <Julia.Lawall@inria.fr>,
"Michał Mirosław" <mirq-linux@rere.qmqm.pl>,
"Nicholas Piggin" <npiggin@gmail.com>,
"Nicolas Palix" <nicolas.palix@imag.fr>,
"Peter Zijlstra" <peterz@infradead.org>,
"Rasmus Villemoes" <linux@rasmusvillemoes.dk>,
"Matti Vaittinen" <Matti.Vaittinen@fi.rohmeurope.com>,
linux-kernel@vger.kernel.org
Cc: Yury Norov <yury.norov@gmail.com>,
Balbir Singh <sblbir@amazon.com>,
Boris Ostrovsky <boris.ostrovsky@oracle.com>,
Borislav Petkov <bp@alien8.de>,
Dave Hansen <dave.hansen@linux.intel.com>,
"H . Peter Anvin" <hpa@zytor.com>, Huang Rui <ray.huang@amd.com>,
Ingo Molnar <mingo@redhat.com>,
"Paul E . McKenney" <paulmck@kernel.org>,
"Rafael J . Wysocki" <rafael.j.wysocki@intel.com>,
Sean Christopherson <seanjc@google.com>,
Thomas Gleixner <tglx@linutronix.de>,
Tim Chen <tim.c.chen@linux.intel.com>,
x86@kernel.org
Subject: [PATCH 13/22] x86: smp: move cpumask_weight() out of for-loop in remove_siblinginfo
Date: Tue, 10 May 2022 08:47:41 -0700 [thread overview]
Message-ID: <20220510154750.212913-14-yury.norov@gmail.com> (raw)
In-Reply-To: <20220510154750.212913-1-yury.norov@gmail.com>
Because argument of the function is constant inside for_each_cpu()
loop, the cpumask_weight() does the same work O(NR_CPUS) times, while
it may be calculated only once.
This patch moves cpumask_weight() out of the loop and replaces it
with cpumask_weight_eq(). While here, fix comment format.
CC: Balbir Singh <sblbir@amazon.com>
CC: Boris Ostrovsky <boris.ostrovsky@oracle.com>
CC: Borislav Petkov <bp@alien8.de>
CC: Dave Hansen <dave.hansen@linux.intel.com>
CC: H. Peter Anvin <hpa@zytor.com>
CC: Huang Rui <ray.huang@amd.com>
CC: Ingo Molnar <mingo@redhat.com>
CC: Paul E. McKenney <paulmck@kernel.org>
CC: Peter Zijlstra <peterz@infradead.org>
CC: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
CC: Sean Christopherson <seanjc@google.com>
CC: Thomas Gleixner <tglx@linutronix.de>
CC: Tim Chen <tim.c.chen@linux.intel.com>
CC: x86@kernel.org
CC: linux-kernel@vger.kernel.org
Signed-off-by: Yury Norov <yury.norov@gmail.com>
---
arch/x86/kernel/smpboot.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kernel/smpboot.c b/arch/x86/kernel/smpboot.c
index 5e7f9532a10d..7d948f79ef31 100644
--- a/arch/x86/kernel/smpboot.c
+++ b/arch/x86/kernel/smpboot.c
@@ -1605,13 +1605,14 @@ static void remove_siblinginfo(int cpu)
{
int sibling;
struct cpuinfo_x86 *c = &cpu_data(cpu);
+ bool last_thread_sibling = cpumask_weight_eq(topology_sibling_cpumask(cpu), 1);
for_each_cpu(sibling, topology_core_cpumask(cpu)) {
cpumask_clear_cpu(cpu, topology_core_cpumask(sibling));
- /*/
+ /*
* last thread sibling in this cpu core going down
*/
- if (cpumask_weight(topology_sibling_cpumask(cpu)) == 1)
+ if (last_thread_sibling)
cpu_data(sibling).booted_cores--;
}
--
2.32.0
next prev parent reply other threads:[~2022-05-10 15:58 UTC|newest]
Thread overview: 44+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-10 15:47 [PATCH 00/21] add coccinelle scripts for {bitmap,cpumask,nodes}_empty() Yury Norov
2022-05-10 15:47 ` [PATCH 01/22] introduce bitmap.cocci Yury Norov
2022-05-10 15:47 ` [PATCH 02/22] introduce cpumask.cocci Yury Norov
2022-05-10 15:47 ` [PATCH 03/22] introduce nodemask.cocci Yury Norov
2022-05-10 15:47 ` [PATCH 04/22] ice: use bitmap_empty() in ice_vf_has_no_qs_ena() Yury Norov
2022-05-10 15:47 ` [PATCH 05/22] iio: replace bitmap_weight with bitmap_weitght_{eq,le} where appropriate Yury Norov
2022-05-14 15:53 ` Jonathan Cameron
2022-05-14 16:31 ` Joe Perches
2022-05-15 16:40 ` Jonathan Cameron
2022-05-10 15:47 ` [PATCH 06/22] octeontx2: use bitmap_empty() instead of bitmap_weight() Yury Norov
2022-05-10 21:31 ` Jakub Kicinski
2022-05-10 15:47 ` [PATCH 07/22] risc-v: replace bitmap_weight with bitmap_empty in riscv_fill_hwcap() Yury Norov
2022-05-10 16:31 ` Anup Patel
2022-05-10 15:47 ` [PATCH 08/22] bitops: introduce MANY_BITS() macro Yury Norov
2022-05-10 16:50 ` Alexei Starovoitov
2022-05-10 17:54 ` David Laight
2022-05-10 19:11 ` Yury Norov
2022-05-11 10:59 ` Rasmus Villemoes
2022-05-10 17:57 ` Max Filippov
2022-05-10 19:16 ` Yury Norov
2022-05-11 4:55 ` Max Filippov
2022-05-10 15:47 ` [PATCH 09/22] qed: replace bitmap_weight() with MANY_BITS() Yury Norov
2022-05-10 15:47 ` [PATCH 10/22] net/mlx5e: simplify mlx5e_set_fecparam() Yury Norov
2022-05-10 15:47 ` [PATCH 11/22] KVM: x86: hyper-v: replace bitmap_weight() with hweight64() Yury Norov
2022-05-16 13:08 ` Vitaly Kuznetsov
2022-05-22 14:53 ` Guenter Roeck
2022-05-22 17:39 ` Yury Norov
2022-05-10 15:47 ` [PATCH 12/22] ia64: cleanup remove_siblinginfo() Yury Norov
2022-05-10 22:33 ` Andrew Morton
2022-05-10 15:47 ` Yury Norov [this message]
2022-05-11 9:47 ` [PATCH 13/22] x86: smp: move cpumask_weight() out of for-loop in remove_siblinginfo Thomas Gleixner
2022-05-10 15:47 ` [PATCH 14/22] x86: smp: use cpumask_weight_eq() " Yury Norov
2022-05-10 15:47 ` [PATCH 15/22] net/mlx5: use cpumask_weight_gt() in irq_pool_request_irq() Yury Norov
2022-05-10 15:47 ` [PATCH 16/22] x86/tsc: use cpumask_weight_gt() in loop_timeout() Yury Norov
2022-05-10 15:47 ` [PATCH 17/22] sched/core: fix opencoded cpumask_any_but() Yury Norov
2022-05-10 16:37 ` Peter Zijlstra
2022-05-10 17:21 ` Valentin Schneider
2022-05-10 15:47 ` [PATCH 18/22] sched/core: remove unneeded cpumask_weight() in sched_core_cpu_{starting,deactivate} Yury Norov
2022-05-10 15:47 ` [PATCH 19/22] sched/core: replace cpumask_weight() with cpumask_weight_eq() where appropriate Yury Norov
2022-05-10 15:47 ` [PATCH 20/22] sched/topology: " Yury Norov
2022-05-10 15:47 ` [PATCH 21/22] cpufreq: use cpumask_weight_gt() in policy_is_shared() Yury Norov
2022-05-11 3:16 ` Viresh Kumar
2022-05-10 15:47 ` [PATCH 22/22] clockevents: use cpumask_weight_eq() in tick_cleanup_dead_cpu() Yury Norov
2022-05-11 8:18 ` Thomas Gleixner
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