linux-kernel - [tip: sched/core] sched/cpuacct: Use __this_cpu_add() instead of this_cpu

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Message-ID: <158991385587.17951.10383414133329155280.tip-bot2@tip-bot2>
Date:   Tue, 19 May 2020 18:44:15 -0000
From:   "tip-bot2 for Muchun Song" <tip-bot2@...utronix.de>
To:     linux-tip-commits@...r.kernel.org
Cc:     Muchun Song <songmuchun@...edance.com>,
        "Peter Zijlstra (Intel)" <peterz@...radead.org>,
        x86 <x86@...nel.org>, LKML <linux-kernel@...r.kernel.org>
Subject: [tip: sched/core] sched/cpuacct: Use __this_cpu_add() instead of
 this_cpu_ptr()

The following commit has been merged into the sched/core branch of tip:

Commit-ID:     12aa2587388de6697fd2e585ae6a90f70249540b
Gitweb:        https://git.kernel.org/tip/12aa2587388de6697fd2e585ae6a90f70249540b
Author:        Muchun Song <songmuchun@...edance.com>
AuthorDate:    Thu, 07 May 2020 11:10:39 +08:00
Committer:     Peter Zijlstra <peterz@...radead.org>
CommitterDate: Tue, 19 May 2020 20:34:13 +02:00

sched/cpuacct: Use __this_cpu_add() instead of this_cpu_ptr()

The cpuacct_charge() and cpuacct_account_field() are called with
rq->lock held, and this means preemption(and IRQs) are indeed
disabled, so it is safe to use __this_cpu_*() to allow for better
code-generation.

Signed-off-by: Muchun Song <songmuchun@...edance.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@...radead.org>
Link: https://lkml.kernel.org/r/20200507031039.32615-1-songmuchun@bytedance.com
---
 kernel/sched/cpuacct.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c
index 9fbb103..6448b04 100644
--- a/kernel/sched/cpuacct.c
+++ b/kernel/sched/cpuacct.c
@@ -347,7 +347,7 @@ void cpuacct_charge(struct task_struct *tsk, u64 cputime)
 	rcu_read_lock();
 
 	for (ca = task_ca(tsk); ca; ca = parent_ca(ca))
-		this_cpu_ptr(ca->cpuusage)->usages[index] += cputime;
+		__this_cpu_add(ca->cpuusage->usages[index], cputime);
 
 	rcu_read_unlock();
 }
@@ -363,7 +363,7 @@ void cpuacct_account_field(struct task_struct *tsk, int index, u64 val)
 
 	rcu_read_lock();
 	for (ca = task_ca(tsk); ca != &root_cpuacct; ca = parent_ca(ca))
-		this_cpu_ptr(ca->cpustat)->cpustat[index] += val;
+		__this_cpu_add(ca->cpustat->cpustat[index], val);
 	rcu_read_unlock();
 }