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From: Rik van Riel <riel@surriel.com>
To: linux-kernel@vger.kernel.org
Cc: kernel-team@fb.com, mingo@kernel.org, peterz@infradead.org,
	luto@kernel.org, x86@kernel.org, efault@gmx.de,
	dave.hansen@intel.com, Rik van Riel <riel@surriel.com>
Subject: [PATCH 02/11] smp: use __cpumask_set_cpu in on_each_cpu_cond
Date: Wed,  1 Aug 2018 06:02:46 -0400	[thread overview]
Message-ID: <20180801100255.4278-3-riel@surriel.com> (raw)
In-Reply-To: <20180801100255.4278-1-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>
Reviewed-by: Andy Lutomirski <luto@kernel.org>
---
 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


  parent reply	other threads:[~2018-08-01 10:03 UTC|newest]

Thread overview: 17+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-08-01 10:02 [PATCH v2 0/11] x86,tlb,mm: more lazy TLB cleanups & optimizations Rik van Riel
2018-08-01 10:02 ` [PATCH 01/11] x86,tlb: clarify memory barrier in switch_mm_irqs_off Rik van Riel
2018-08-01 10:02 ` Rik van Riel [this message]
2018-08-01 10:02 ` [PATCH 03/11] smp,cpumask: introduce on_each_cpu_cond_mask Rik van Riel
2018-08-01 10:02 ` [PATCH 04/11] x86,mm: use on_each_cpu_cond for TLB flushes Rik van Riel
2018-08-01 10:02 ` [PATCH 05/11] mm,tlb: turn dummy defines into inline functions Rik van Riel
2018-08-01 10:02 ` [PATCH 06/11] mm,x86: skip cr4 and ldt reload when mm stays the same Rik van Riel
2018-08-01 10:02 ` [PATCH 07/11] x86,mm: remove leave_mm cpu argument Rik van Riel
2018-08-01 10:02 ` [PATCH 08/11] arch,mm: add config variable to skip lazy TLB mm refcounting Rik van Riel
2018-08-01 10:02 ` [PATCH 09/11] mm,x86: shoot down lazy TLB references at exit_mmap time Rik van Riel
2018-08-01 10:02 ` [PATCH 10/11] x86,tlb: really leave mm on shootdown Rik van Riel
2018-08-01 10:02 ` [PATCH 11/11] mm,sched: conditionally skip lazy TLB mm refcounting Rik van Riel
2018-08-03 15:56   ` Peter Zijlstra
2018-08-03 16:40     ` Rik van Riel
2018-08-03 17:25       ` Peter Zijlstra
2018-08-03 17:39         ` Rik van Riel
2018-08-06 17:50           ` Peter Zijlstra

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