Messages in this thread |  | | Date | Sun, 6 Apr 2008 01:10:41 +0530 | From | Dhaval Giani <> | Subject | Re: [RFC][-mm] [1/2] Simple stats for cpu resource controller |
| |
On Sat, Apr 05, 2008 at 11:39:46PM +0530, Balaji Rao wrote: > This patch implements some trivial statistics for the CPU controller. > > As per our current requirements, we have decided to keep the stats tick based as opposed to using CFS precise accounting. > > Signed-off-by: Balaji Rao <balajirrao@gmail.com> > CC: Balbir Singh <balbir@linux.vnet.ibm.com> > CC: Dhaval Giani <dhaval@linux.vnet.ibm.com> > > diff --git a/kernel/sched.c b/kernel/sched.c > index 8206fda..e2acf06 100644 > --- a/kernel/sched.c > +++ b/kernel/sched.c > @@ -164,10 +164,38 @@ struct cfs_rq; > > static LIST_HEAD(task_groups); > > +#ifdef CONFIG_CGROUP_SCHED > +enum cpu_cgroup_stat_index { > + CPU_CGROUP_STAT_UTIME, /* Usertime of the task group */ > + CPU_CGROUP_STAT_STIME, /* Kerneltime of the task group */ > + > + CPU_CGROUP_STAT_NSTATS,
why the extra space?
> +}; > + > +struct cpu_cgroup_stat_cpu { > + s64 count[CPU_CGROUP_STAT_NSTATS];
u64? time does not go negative :) count also is not very clear? Can you give a more descriptive name?
> +} ____cacheline_aligned_in_smp; > + > +struct cpu_cgroup_stat { > + struct cpu_cgroup_stat_cpu cpustat[NR_CPUS]; > +}; > + > +/* Called under irq disable. */ > +static void __cpu_cgroup_stat_add(struct cpu_cgroup_stat *stat, > + enum cpu_cgroup_stat_index idx, int val) > +{ > + int cpu = smp_processor_id(); > + > + BUG_ON(!irqs_disabled()); > + stat->cpustat[cpu].count[idx] += val; > +} > +#endif > + > /* task group related information */ > struct task_group { > #ifdef CONFIG_CGROUP_SCHED > struct cgroup_subsys_state css; > + struct cpu_cgroup_stat stat; > #endif > > #ifdef CONFIG_FAIR_GROUP_SCHED > @@ -3733,6 +3761,16 @@ void account_user_time(struct task_struct *p, cputime_t cputime) > cpustat->nice = cputime64_add(cpustat->nice, tmp); > else > cpustat->user = cputime64_add(cpustat->user, tmp); > + > + /* Charge the task's group */ > +#ifdef CONFIG_CGROUP_SCHED > + { > + struct task_group *tg; > + tg = task_group(p); > + __cpu_cgroup_stat_add(&tg->stat, CPU_CGROUP_STAT_UTIME, > + cputime_to_msecs(cputime)); > + } > +#endif > } > > /* > @@ -3796,6 +3834,15 @@ void account_system_time(struct task_struct *p, int hardirq_offset, > cpustat->idle = cputime64_add(cpustat->idle, tmp); > /* Account for system time used */ > acct_update_integrals(p); > + > +#ifdef CONFIG_CGROUP_SCHED > + { > + struct task_group *tg; > + tg = task_group(p); > + __cpu_cgroup_stat_add(&tg->stat, CPU_CGROUP_STAT_STIME, > + cputime_to_msecs(cputime)); > + } > +#endif > } > > /* > @@ -8004,6 +8051,45 @@ static u64 cpu_shares_read_u64(struct cgroup *cgrp, struct cftype *cft) > > return (u64) tg->shares; > } > + > +static s64 cpu_cgroup_read_stat(struct cpu_cgroup_stat *stat, > + enum cpu_cgroup_stat_index idx) > +{ > + int cpu; > + s64 ret = 0; > + unsigned long flags;
> + > + local_irq_save(flags);
I am just wondering. Is local_irq_save() enough?
> + for_each_possible_cpu(cpu) > + ret += stat->cpustat[cpu].count[idx]; > + local_irq_restore(flags); > + > + return ret; > +} > + > +static const struct cpu_cgroup_stat_desc { > + const char *msg; > + u64 unit; > +} cpu_cgroup_stat_desc[] = { > + [CPU_CGROUP_STAT_UTIME] = { "utime", 1, }, > + [CPU_CGROUP_STAT_STIME] = { "stime", 1, }, > +}; > + > +static int cpu_cgroup_stats_show(struct cgroup *cgrp, struct cftype *cft, > + struct cgroup_map_cb *cb) > +{ > + struct task_group *tg = cgroup_tg(cgrp); > + struct cpu_cgroup_stat *stat = &tg->stat; > + int i; > + > + for (i = 0; i < ARRAY_SIZE(stat->cpustat[0].count); i++) { > + s64 val; > + val = cpu_cgroup_read_stat(stat, i); > + val *= cpu_cgroup_stat_desc[i].unit; > + cb->fill(cb, cpu_cgroup_stat_desc[i].msg, val); > + } > + return 0; > +} > #endif > > #ifdef CONFIG_RT_GROUP_SCHED > @@ -8026,6 +8112,11 @@ static struct cftype cpu_files[] = { > .read_u64 = cpu_shares_read_u64, > .write_u64 = cpu_shares_write_u64, > }, > + > + { > + .name = "stat", > + .read_map = cpu_cgroup_stats_show, > + }, > #endif > #ifdef CONFIG_RT_GROUP_SCHED > { >
-- regards, Dhaval
|  |