| Message ID | 1528340317-5251-2-git-send-email-gavin.guo@canonical.com |
|---|---|
| State | New |
| Headers | show |
| Series | [SRU,Xenial] sched/cpuacct: Simplify the cpuacct code | expand |
On 06/06/18 19:58, Gavin Guo wrote: > From: Zhao Lei <zhaolei@cn.fujitsu.com> > > BugLink: https://bugs.launchpad.net/bugs/1775326 > > - 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 <peterz@infradead.org> > Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> > Cc: Linus Torvalds <torvalds@linux-foundation.org> > Cc: Tejun Heo <htejun@gmail.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Link: http://lkml.kernel.org/r/d8a7ef9592f55224630cb26dea239f05b6398a4e.1458187654.git.zhaolei@cn.fujitsu.com > Signed-off-by: Ingo Molnar <mingo@kernel.org> > (cherry picked from commit 73e6aafd9ea81498d31361f01db84a0118da2d1c) > Signed-off-by: Gavin Guo <gavin.guo@canonical.com> Acked-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com> > --- > 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 dd7cbb55bbf2..e14cfd0e8f20 100644 > --- a/kernel/sched/cpuacct.c > +++ b/kernel/sched/cpuacct.c > @@ -235,23 +235,10 @@ 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(); > } > > @@ -260,18 +247,13 @@ 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 ed605624a5e7..ba72807c73d4 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) > { > } > >
On 06.06.2018 19:58, Gavin Guo wrote: > From: Zhao Lei <zhaolei@cn.fujitsu.com> > > BugLink: https://bugs.launchpad.net/bugs/1775326 > > - 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 <peterz@infradead.org> > Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> > Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> > Cc: Linus Torvalds <torvalds@linux-foundation.org> > Cc: Tejun Heo <htejun@gmail.com> > Cc: Thomas Gleixner <tglx@linutronix.de> > Link: http://lkml.kernel.org/r/d8a7ef9592f55224630cb26dea239f05b6398a4e.1458187654.git.zhaolei@cn.fujitsu.com > Signed-off-by: Ingo Molnar <mingo@kernel.org> > (cherry picked from commit 73e6aafd9ea81498d31361f01db84a0118da2d1c) > Signed-off-by: Gavin Guo <gavin.guo@canonical.com> Acked-by: Stefan Bader <stefan.bader@canonical.com> > --- > 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 dd7cbb55bbf2..e14cfd0e8f20 100644 > --- a/kernel/sched/cpuacct.c > +++ b/kernel/sched/cpuacct.c > @@ -235,23 +235,10 @@ 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(); > } > > @@ -260,18 +247,13 @@ 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 ed605624a5e7..ba72807c73d4 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) > { > } > >
diff --git a/kernel/sched/cpuacct.c b/kernel/sched/cpuacct.c index dd7cbb55bbf2..e14cfd0e8f20 100644 --- a/kernel/sched/cpuacct.c +++ b/kernel/sched/cpuacct.c @@ -235,23 +235,10 @@ 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(); } @@ -260,18 +247,13 @@ 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 ed605624a5e7..ba72807c73d4 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) { }