From: Rik van Riel <riel@surriel.com>
To: linux-kernel@vger.kernel.org
Cc: kernel-team@fb.com, peterz@infradead.org, luto@kernel.org,
x86@kernel.org, vkuznets@redhat.com, mingo@kernel.org,
efault@gmx.de, dave.hansen@intel.com, will.daecon@arm.com,
catalin.marinas@arm.com, benh@kernel.crashing.org,
Rik van Riel <riel@surriel.com>
Subject: [PATCH 02/10] smp: use __cpumask_set_cpu in on_each_cpu_cond
Date: Sat, 28 Jul 2018 17:53:49 -0400 [thread overview]
Message-ID: <20180728215357.3249-3-riel@surriel.com> (raw)
In-Reply-To: <20180728215357.3249-1-riel@surriel.com>
The code in on_each_cpu_cond sets CPUs in a locally allocated bitmask,
which should never be used by other CPUs simultaneously. There is no
need to use locked memory accesses to set the bits in this bitmap.
Switch to __cpumask_set_cpu.
Suggested-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Rik van Riel <riel@surriel.com>
---
kernel/smp.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/kernel/smp.c b/kernel/smp.c
index 084c8b3a2681..2dbc842dd385 100644
--- a/kernel/smp.c
+++ b/kernel/smp.c
@@ -680,7 +680,7 @@ void on_each_cpu_cond(bool (*cond_func)(int cpu, void *info),
preempt_disable();
for_each_online_cpu(cpu)
if (cond_func(cpu, info))
- cpumask_set_cpu(cpu, cpus);
+ __cpumask_set_cpu(cpu, cpus);
on_each_cpu_mask(cpus, func, info, wait);
preempt_enable();
free_cpumask_var(cpus);
--
2.14.4
next prev parent reply other threads:[~2018-07-28 21:54 UTC|newest]
Thread overview: 43+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-07-28 21:53 [PATCH 0/10] x86,tlb,mm: more lazy TLB cleanups & optimizations Rik van Riel
2018-07-28 21:53 ` [PATCH 01/10] x86,tlb: clarify memory barrier in switch_mm_irqs_off Rik van Riel
2018-07-29 2:59 ` Andy Lutomirski
2018-07-28 21:53 ` Rik van Riel [this message]
2018-07-29 2:59 ` [PATCH 02/10] smp: use __cpumask_set_cpu in on_each_cpu_cond Andy Lutomirski
2018-07-28 21:53 ` [PATCH 03/10] smp,cpumask: introduce on_each_cpu_cond_mask Rik van Riel
2018-07-29 2:57 ` Andy Lutomirski
2018-07-29 12:00 ` Rik van Riel
[not found] ` <E710FBA5-CC5E-4941-ACBF-4AB3424F1F68@amacapital.net>
2018-07-29 17:39 ` Rik van Riel
2018-07-29 17:51 ` Rik van Riel
2018-07-29 18:55 ` Andy Lutomirski
2018-07-29 19:56 ` Linus Torvalds
2018-07-28 21:53 ` [PATCH 04/10] x86,mm: use on_each_cpu_cond for TLB flushes Rik van Riel
2018-07-29 2:58 ` Andy Lutomirski
2018-07-29 12:02 ` Rik van Riel
2018-07-28 21:53 ` [PATCH 05/10] mm,tlb: turn dummy defines into inline functions Rik van Riel
2018-07-28 21:53 ` [PATCH 06/10] mm,x86: skip cr4 and ldt reload when mm stays the same Rik van Riel
2018-07-29 4:21 ` Andy Lutomirski
2018-07-28 21:53 ` [PATCH 07/10] x86,mm: remove leave_mm cpu argument Rik van Riel
2018-07-28 21:53 ` [PATCH 08/10] arch,mm: add config variable to skip lazy TLB mm refcounting Rik van Riel
2018-07-28 21:53 ` [PATCH 09/10] mm,x86: shoot down lazy TLB references at exit_mmap time Rik van Riel
2018-07-28 21:53 ` [PATCH 10/10] mm,sched: conditionally skip lazy TLB mm refcounting Rik van Riel
2018-07-29 4:21 ` Andy Lutomirski
2018-07-29 12:11 ` Rik van Riel
2018-07-29 15:29 ` Andy Lutomirski
2018-07-29 16:55 ` Rik van Riel
2018-07-29 19:54 ` [PATCH v2 10/11] x86,tlb: really leave mm on shootdown Rik van Riel
2018-07-29 19:54 ` [PATCH v2 11/11] mm,sched: conditionally skip lazy TLB mm refcounting Rik van Riel
2018-07-30 9:55 ` Peter Zijlstra
2018-07-30 14:30 ` Rik van Riel
2018-07-30 16:26 ` Peter Zijlstra
2018-07-30 19:15 ` Rik van Riel
2018-07-30 19:30 ` Andy Lutomirski
2018-07-30 19:36 ` Rik van Riel
2018-07-30 19:49 ` Andy Lutomirski
2018-07-30 21:46 ` Rik van Riel
2018-07-30 22:00 ` Andy Lutomirski
2018-07-31 1:05 ` Rik van Riel
2018-07-31 9:12 ` Peter Zijlstra
2018-07-31 14:29 ` Andy Lutomirski
2018-07-31 15:03 ` Rik van Riel
2018-07-31 15:12 ` Peter Zijlstra
2018-07-30 11:32 ` [PATCH 0/10] x86,tlb,mm: more lazy TLB cleanups & optimizations Ingo Molnar
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