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author | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-18 08:27:54 -0700 |
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committer | Linus Torvalds <torvalds@linux-foundation.org> | 2010-05-18 08:27:54 -0700 |
commit | b8ae30ee26d379db436b0b8c8c3ff1b52f69e5d1 (patch) | |
tree | 506aa0b4bdbf90f61e7e9261c7db90aa1452dcce /drivers | |
parent | 4d7b4ac22fbec1a03206c6cde353f2fd6942f828 (diff) | |
parent | 9c6f7e43b4e02c161b53e97ba913855246876c61 (diff) |
Merge branch 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip
* 'sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/linux-2.6-tip: (49 commits)
stop_machine: Move local variable closer to the usage site in cpu_stop_cpu_callback()
sched, wait: Use wrapper functions
sched: Remove a stale comment
ondemand: Make the iowait-is-busy time a sysfs tunable
ondemand: Solve a big performance issue by counting IOWAIT time as busy
sched: Intoduce get_cpu_iowait_time_us()
sched: Eliminate the ts->idle_lastupdate field
sched: Fold updating of the last_update_time_info into update_ts_time_stats()
sched: Update the idle statistics in get_cpu_idle_time_us()
sched: Introduce a function to update the idle statistics
sched: Add a comment to get_cpu_idle_time_us()
cpu_stop: add dummy implementation for UP
sched: Remove rq argument to the tracepoints
rcu: need barrier() in UP synchronize_sched_expedited()
sched: correctly place paranioa memory barriers in synchronize_sched_expedited()
sched: kill paranoia check in synchronize_sched_expedited()
sched: replace migration_thread with cpu_stop
stop_machine: reimplement using cpu_stop
cpu_stop: implement stop_cpu[s]()
sched: Fix select_idle_sibling() logic in select_task_rq_fair()
...
Diffstat (limited to 'drivers')
-rw-r--r-- | drivers/cpufreq/cpufreq_ondemand.c | 75 | ||||
-rw-r--r-- | drivers/xen/manage.c | 14 |
2 files changed, 75 insertions, 14 deletions
diff --git a/drivers/cpufreq/cpufreq_ondemand.c b/drivers/cpufreq/cpufreq_ondemand.c index bd444dc93cf2..8e9dbdc6c700 100644 --- a/drivers/cpufreq/cpufreq_ondemand.c +++ b/drivers/cpufreq/cpufreq_ondemand.c @@ -73,6 +73,7 @@ enum {DBS_NORMAL_SAMPLE, DBS_SUB_SAMPLE}; struct cpu_dbs_info_s { cputime64_t prev_cpu_idle; + cputime64_t prev_cpu_iowait; cputime64_t prev_cpu_wall; cputime64_t prev_cpu_nice; struct cpufreq_policy *cur_policy; @@ -108,6 +109,7 @@ static struct dbs_tuners { unsigned int down_differential; unsigned int ignore_nice; unsigned int powersave_bias; + unsigned int io_is_busy; } dbs_tuners_ins = { .up_threshold = DEF_FREQUENCY_UP_THRESHOLD, .down_differential = DEF_FREQUENCY_DOWN_DIFFERENTIAL, @@ -148,6 +150,16 @@ static inline cputime64_t get_cpu_idle_time(unsigned int cpu, cputime64_t *wall) return idle_time; } +static inline cputime64_t get_cpu_iowait_time(unsigned int cpu, cputime64_t *wall) +{ + u64 iowait_time = get_cpu_iowait_time_us(cpu, wall); + + if (iowait_time == -1ULL) + return 0; + + return iowait_time; +} + /* * Find right freq to be set now with powersave_bias on. * Returns the freq_hi to be used right now and will set freq_hi_jiffies, @@ -249,6 +261,7 @@ static ssize_t show_##file_name \ return sprintf(buf, "%u\n", dbs_tuners_ins.object); \ } show_one(sampling_rate, sampling_rate); +show_one(io_is_busy, io_is_busy); show_one(up_threshold, up_threshold); show_one(ignore_nice_load, ignore_nice); show_one(powersave_bias, powersave_bias); @@ -299,6 +312,23 @@ static ssize_t store_sampling_rate(struct kobject *a, struct attribute *b, return count; } +static ssize_t store_io_is_busy(struct kobject *a, struct attribute *b, + const char *buf, size_t count) +{ + unsigned int input; + int ret; + + ret = sscanf(buf, "%u", &input); + if (ret != 1) + return -EINVAL; + + mutex_lock(&dbs_mutex); + dbs_tuners_ins.io_is_busy = !!input; + mutex_unlock(&dbs_mutex); + + return count; +} + static ssize_t store_up_threshold(struct kobject *a, struct attribute *b, const char *buf, size_t count) { @@ -381,6 +411,7 @@ static struct global_attr _name = \ __ATTR(_name, 0644, show_##_name, store_##_name) define_one_rw(sampling_rate); +define_one_rw(io_is_busy); define_one_rw(up_threshold); define_one_rw(ignore_nice_load); define_one_rw(powersave_bias); @@ -392,6 +423,7 @@ static struct attribute *dbs_attributes[] = { &up_threshold.attr, &ignore_nice_load.attr, &powersave_bias.attr, + &io_is_busy.attr, NULL }; @@ -470,14 +502,15 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info) for_each_cpu(j, policy->cpus) { struct cpu_dbs_info_s *j_dbs_info; - cputime64_t cur_wall_time, cur_idle_time; - unsigned int idle_time, wall_time; + cputime64_t cur_wall_time, cur_idle_time, cur_iowait_time; + unsigned int idle_time, wall_time, iowait_time; unsigned int load, load_freq; int freq_avg; j_dbs_info = &per_cpu(od_cpu_dbs_info, j); cur_idle_time = get_cpu_idle_time(j, &cur_wall_time); + cur_iowait_time = get_cpu_iowait_time(j, &cur_wall_time); wall_time = (unsigned int) cputime64_sub(cur_wall_time, j_dbs_info->prev_cpu_wall); @@ -487,6 +520,10 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info) j_dbs_info->prev_cpu_idle); j_dbs_info->prev_cpu_idle = cur_idle_time; + iowait_time = (unsigned int) cputime64_sub(cur_iowait_time, + j_dbs_info->prev_cpu_iowait); + j_dbs_info->prev_cpu_iowait = cur_iowait_time; + if (dbs_tuners_ins.ignore_nice) { cputime64_t cur_nice; unsigned long cur_nice_jiffies; @@ -504,6 +541,16 @@ static void dbs_check_cpu(struct cpu_dbs_info_s *this_dbs_info) idle_time += jiffies_to_usecs(cur_nice_jiffies); } + /* + * For the purpose of ondemand, waiting for disk IO is an + * indication that you're performance critical, and not that + * the system is actually idle. So subtract the iowait time + * from the cpu idle time. + */ + + if (dbs_tuners_ins.io_is_busy && idle_time >= iowait_time) + idle_time -= iowait_time; + if (unlikely(!wall_time || wall_time < idle_time)) continue; @@ -617,6 +664,29 @@ static inline void dbs_timer_exit(struct cpu_dbs_info_s *dbs_info) cancel_delayed_work_sync(&dbs_info->work); } +/* + * Not all CPUs want IO time to be accounted as busy; this dependson how + * efficient idling at a higher frequency/voltage is. + * Pavel Machek says this is not so for various generations of AMD and old + * Intel systems. + * Mike Chan (androidlcom) calis this is also not true for ARM. + * Because of this, whitelist specific known (series) of CPUs by default, and + * leave all others up to the user. + */ +static int should_io_be_busy(void) +{ +#if defined(CONFIG_X86) + /* + * For Intel, Core 2 (model 15) andl later have an efficient idle. + */ + if (boot_cpu_data.x86_vendor == X86_VENDOR_INTEL && + boot_cpu_data.x86 == 6 && + boot_cpu_data.x86_model >= 15) + return 1; +#endif + return 0; +} + static int cpufreq_governor_dbs(struct cpufreq_policy *policy, unsigned int event) { @@ -679,6 +749,7 @@ static int cpufreq_governor_dbs(struct cpufreq_policy *policy, dbs_tuners_ins.sampling_rate = max(min_sampling_rate, latency * LATENCY_MULTIPLIER); + dbs_tuners_ins.io_is_busy = should_io_be_busy(); } mutex_unlock(&dbs_mutex); diff --git a/drivers/xen/manage.c b/drivers/xen/manage.c index 2ac4440e7b08..8943b8ccee1a 100644 --- a/drivers/xen/manage.c +++ b/drivers/xen/manage.c @@ -80,12 +80,6 @@ static void do_suspend(void) shutting_down = SHUTDOWN_SUSPEND; - err = stop_machine_create(); - if (err) { - printk(KERN_ERR "xen suspend: failed to setup stop_machine %d\n", err); - goto out; - } - #ifdef CONFIG_PREEMPT /* If the kernel is preemptible, we need to freeze all the processes to prevent them from being in the middle of a pagetable update @@ -93,7 +87,7 @@ static void do_suspend(void) err = freeze_processes(); if (err) { printk(KERN_ERR "xen suspend: freeze failed %d\n", err); - goto out_destroy_sm; + goto out; } #endif @@ -136,12 +130,8 @@ out_resume: out_thaw: #ifdef CONFIG_PREEMPT thaw_processes(); - -out_destroy_sm: -#endif - stop_machine_destroy(); - out: +#endif shutting_down = SHUTDOWN_INVALID; } #endif /* CONFIG_PM_SLEEP */ |