Commit-ID: 73e6aafd9ea81498d31361f01db84a0118da2d1c Gitweb: http://git.kernel.org/tip/73e6aafd9ea81498d31361f01db84a0118da2d1c Author: Zhao Lei <[email protected]> AuthorDate: Thu, 17 Mar 2016 12:19:43 +0800 Committer: Ingo Molnar <[email protected]> CommitDate: Mon, 21 Mar 2016 11:00:28 +0100
sched/cpuacct: Simplify the cpuacct code - Use for() instead of while() loop in some functions to make the code simpler. - Use this_cpu_ptr() instead of per_cpu_ptr() to make the code cleaner and a bit faster. Suggested-by: Peter Zijlstra <[email protected]> Signed-off-by: Zhao Lei <[email protected]> Signed-off-by: Peter Zijlstra (Intel) <[email protected]> Cc: Linus Torvalds <[email protected]> Cc: Tejun Heo <[email protected]> Cc: Thomas Gleixner <[email protected]> Link: http://lkml.kernel.org/r/d8a7ef9592f55224630cb26dea239f05b6398a4e.1458187654.git.zhao...@cn.fujitsu.com Signed-off-by: Ingo Molnar <[email protected]> --- kernel/sched/cpuacct.c | 28 +++++----------------------- kernel/sched/cpuacct.h | 4 ++-- 2 files changed, 7 insertions(+), 25 deletions(-) diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c index 9c2bbf7..434c2fa 100644 --- a/kernel/sched/cpuacct.c +++ b/kernel/sched/cpuacct.c @@ -238,23 +238,10 @@ static struct cftype files[] = { void cpuacct_charge(struct task_struct *tsk, u64 cputime) { struct cpuacct *ca; - int cpu; - - cpu = task_cpu(tsk); rcu_read_lock(); - - ca = task_ca(tsk); - - while (true) { - u64 *cpuusage = per_cpu_ptr(ca->cpuusage, cpu); - *cpuusage += cputime; - - ca = parent_ca(ca); - if (!ca) - break; - } - + for (ca = task_ca(tsk); ca; ca = parent_ca(ca)) + *this_cpu_ptr(ca->cpuusage) += cputime; rcu_read_unlock(); } @@ -263,18 +250,13 @@ void cpuacct_charge(struct task_struct *tsk, u64 cputime) * * Note: it's the caller that updates the account of the root cgroup. */ -void cpuacct_account_field(struct task_struct *p, int index, u64 val) +void cpuacct_account_field(struct task_struct *tsk, int index, u64 val) { - struct kernel_cpustat *kcpustat; struct cpuacct *ca; rcu_read_lock(); - ca = task_ca(p); - while (ca != &root_cpuacct) { - kcpustat = this_cpu_ptr(ca->cpustat); - kcpustat->cpustat[index] += val; - ca = parent_ca(ca); - } + for (ca = task_ca(tsk); ca != &root_cpuacct; ca = parent_ca(ca)) + this_cpu_ptr(ca->cpustat)->cpustat[index] += val; rcu_read_unlock(); } diff --git a/kernel/sched/cpuacct.h b/kernel/sched/cpuacct.h index ed60562..ba72807 100644 --- a/kernel/sched/cpuacct.h +++ b/kernel/sched/cpuacct.h @@ -1,7 +1,7 @@ #ifdef CONFIG_CGROUP_CPUACCT extern void cpuacct_charge(struct task_struct *tsk, u64 cputime); -extern void cpuacct_account_field(struct task_struct *p, int index, u64 val); +extern void cpuacct_account_field(struct task_struct *tsk, int index, u64 val); #else @@ -10,7 +10,7 @@ static inline void cpuacct_charge(struct task_struct *tsk, u64 cputime) } static inline void -cpuacct_account_field(struct task_struct *p, int index, u64 val) +cpuacct_account_field(struct task_struct *tsk, int index, u64 val) { }
