On Wed, Aug 12, 2026 at 11:10:22AM +0530, Shrikanth Hegde wrote: > Provide a new helper function which sums up a given type of cpustat > over a specified cpumask. > > This allows the caller's code to be simpler and avoids duplication. > For example, subsequent patch in the steal governor use this exact > same pattern when calculating steal time. > > Suggested-by: Yury Norov <[email protected]> > Signed-off-by: Shrikanth Hegde <[email protected]>
Reviewed-by: Yury Norov <[email protected]> > --- > arch/s390/kernel/hiperdispatch.c | 8 ++------ > fs/proc/uptime.c | 6 +----- > include/linux/kernel_stat.h | 11 +++++++++++ > 3 files changed, 14 insertions(+), 11 deletions(-) > > diff --git a/arch/s390/kernel/hiperdispatch.c > b/arch/s390/kernel/hiperdispatch.c > index 217206522266..e5c7c818c178 100644 > --- a/arch/s390/kernel/hiperdispatch.c > +++ b/arch/s390/kernel/hiperdispatch.c > @@ -210,13 +210,9 @@ static unsigned long hd_calculate_steal_percentage(void) > int cpus, cpu; > ktime_t now; > > - cpus = 0; > - steal = 0; > percentage = 0; > - for_each_cpu(cpu, &hd_vmvl_cpumask) { > - steal += kcpustat_cpu(cpu).cpustat[CPUTIME_STEAL]; > - cpus++; > - } > + steal = kcpustat_field_total(CPUTIME_STEAL, &hd_vmvl_cpumask); > + cpus = cpumask_weight(&hd_vmvl_cpumask); > /* > * If there is no vertical medium and low CPUs steal time > * is 0 as vertical high CPUs shouldn't experience steal time. > diff --git a/fs/proc/uptime.c b/fs/proc/uptime.c > index 433aa947cd57..53143c66cbe1 100644 > --- a/fs/proc/uptime.c > +++ b/fs/proc/uptime.c > @@ -15,12 +15,8 @@ static int uptime_proc_show(struct seq_file *m, void *v) > struct timespec64 idle; > u64 idle_nsec; > u32 rem; > - int i; > - > - idle_nsec = 0; > - for_each_possible_cpu(i) > - idle_nsec += kcpustat_field(CPUTIME_IDLE, i); > > + idle_nsec = kcpustat_field_total(CPUTIME_IDLE, cpu_possible_mask); > ktime_get_boottime_ts64(&uptime); > timens_add_boottime(&uptime); > > diff --git a/include/linux/kernel_stat.h b/include/linux/kernel_stat.h > index 9ca6c2259dfe..c1e85550bf12 100644 > --- a/include/linux/kernel_stat.h > +++ b/include/linux/kernel_stat.h > @@ -196,6 +196,17 @@ static inline void kcpustat_cpu_fetch(struct > kernel_cpustat *dst, int cpu) > } > #endif /* !CONFIG_VIRT_CPU_ACCOUNTING_GEN */ > > +static inline u64 kcpustat_field_total(enum cpu_usage_stat usage, const > struct cpumask *cpus) > +{ > + u64 total = 0; > + int cpu; > + > + for_each_cpu(cpu, cpus) > + total += kcpustat_field(usage, cpu); > + > + return total; > +} > + > extern void account_user_time(struct task_struct *, u64); > extern void account_guest_time(struct task_struct *, u64); > extern void account_system_time(struct task_struct *, int, u64); > -- > 2.47.3
