Re: high power consumption in recent kernels
From: Norbert Preining
Date: Wed Sep 22 2010 - 11:45:13 EST
Hi Alex, hi all,
sorry for the long silence, I was on business travel and mountaineering
for some weeks.
On Mo, 13 Sep 2010, Alex,Shi wrote:
> > - revert the nohz patch (can you send me a patch for that)
I am now running 2.6.36-rc5 with this patch:
> diff --git a/include/linux/sched.h b/include/linux/sched.h
> index 1e2a6db..e66c52e 100644
> --- a/include/linux/sched.h
> +++ b/include/linux/sched.h
> @@ -274,8 +274,14 @@ extern cpumask_var_t nohz_cpu_mask;
> #if defined(CONFIG_SMP) && defined(CONFIG_NO_HZ)
> extern void select_nohz_load_balancer(int stop_tick);
> extern int get_nohz_timer_target(void);
> +extern int nohz_ratelimit(int cpu);
> #else
> static inline void select_nohz_load_balancer(int stop_tick) { }
> +static inline int nohz_ratelimit(int cpu)
> +{
> + return 0;
> +}
> +
> #endif
>
> /*
> diff --git a/kernel/sched.c b/kernel/sched.c
> index ed09d4f..25399e7 100644
> --- a/kernel/sched.c
> +++ b/kernel/sched.c
> @@ -1182,6 +1182,17 @@ static void resched_task(struct task_struct *p)
> smp_send_reschedule(cpu);
> }
>
> +int nohz_ratelimit(int cpu)
> +{
> + struct rq *rq = cpu_rq(cpu);
> + u64 diff = rq->clock - rq->nohz_stamp;
> +
> + rq->nohz_stamp = rq->clock;
> +
> + return diff < (NSEC_PER_SEC / HZ) >> 1;
> +}
> +
> +
> static void resched_cpu(int cpu)
> {
> struct rq *rq = cpu_rq(cpu);
> diff --git a/kernel/time/tick-sched.c b/kernel/time/tick-sched.c
> index 3e216e0..d6bca17 100644
> --- a/kernel/time/tick-sched.c
> +++ b/kernel/time/tick-sched.c
> @@ -325,7 +325,7 @@ void tick_nohz_stop_sched_tick(int inidle)
> } while (read_seqretry(&xtime_lock, seq));
>
> if (rcu_needs_cpu(cpu) || printk_needs_cpu(cpu) ||
> - arch_needs_cpu(cpu)) {
> + arch_needs_cpu(cpu)|| nohz_ratelimit(cpu)) {
> next_jiffies = last_jiffies + 1;
> delta_jiffies = 1;
> } else {
and it seems that still works nicely. I am now running on battery power,
connected to the internet over bluetooth to my mobile, and get:
Wakeups-from-idle per second : 452.2 interval: 10.0s
Power usage (ACPI estimate): 12.4W (3.6 hours) (long term: 8.0W,/5.6h)
Top causes for wakeups:
16.1% ( 79.5) [yenta, ehci_hcd:usb2, uhci_hcd:usb6, uhci_hcd:usb7, uhci_hcd:
14.3% ( 70.7) [kernel scheduler] Load balancing tick
14.1% ( 69.8) [extra timer interrupt]
13.1% ( 64.9) kworker/0:0
10.7% ( 53.0) USB device 8-2 : BCM2046 Bluetooth Device (Broadcom Corp)
8.4% ( 41.8) [kernel core] hrtimer_start (tick_sched_timer)
3.8% ( 19.0) gnome-terminal
2.9% ( 14.6) icedove-bin
2.2% ( 10.7) PS/2 keyboard/mouse/touchpad interrupt
Which shows that the "Load balancing tick" and "extra timer interrupt" are
down to halfway normal levels. I guess when I shutdown the usb/bluetooth
connection both of them will drop even further.
> > - how to reduce the "extra timer interrupt"?
> The timer was listed in /proc/timer_stats, you can post its contents,
> and let's see what is abnormal here.
Here is the output of /proc/timer_stats:
Timer Stats Version: v0.2
Sample period: 7.828 s
66, 4378 firefox-bin hrtimer_start_range_ns (hrtimer_wakeup)
15, 12527 aptitude hrtimer_start_range_ns (hrtimer_wakeup)
8, 3629 cpufreq-applet hrtimer_start_range_ns (hrtimer_wakeup)
612, 0 swapper hrtimer_start_range_ns (tick_sched_timer)
483D, 6082 kworker/0:0 do_dbs_timer (delayed_work_timer_fn)
17, 12527 aptitude queue_delayed_work (delayed_work_timer_fn)
376, 0 kworker/0:0 hrtimer_start_range_ns (tick_sched_timer)
237D, 6810 kworker/1:1 do_dbs_timer (delayed_work_timer_fn)
51, 7843 sakura hrtimer_start_range_ns (hrtimer_wakeup)
8, 2665 Xorg queue_delayed_work (delayed_work_timer_fn)
387, 0 swapper hrtimer_start (tick_sched_timer)
39, 3510 syndaemon hrtimer_start_range_ns (hrtimer_wakeup)
8, 2705 gpsd hrtimer_start_range_ns (hrtimer_wakeup)
32, 0 swapper __mod_timer (rh_timer_func)
8, 7572 icedove-bin hrtimer_start_range_ns (hrtimer_wakeup)
8, 12916 icedove-bin hrtimer_start_range_ns (hrtimer_wakeup)
8, 12949 icedove-bin hrtimer_start_range_ns (hrtimer_wakeup)
8, 2080 apache2 hrtimer_start_range_ns (hrtimer_wakeup)
8, 2795 ntpd hrtimer_start_range_ns (posix_timer_fn)
26, 3555 yarssr hrtimer_start_range_ns (hrtimer_wakeup)
91, 12790 sakura hrtimer_start_range_ns (hrtimer_wakeup)
15, 3583 multiload-apple hrtimer_start_range_ns (hrtimer_wakeup)
8, 4376 firefox-bin hrtimer_start_range_ns (hrtimer_wakeup)
8, 7579 icedove-bin hrtimer_start_range_ns (hrtimer_wakeup)
8D, 6810 kworker/1:1 queue_delayed_work (delayed_work_timer_fn)
4D, 6810 kworker/1:1 queue_delayed_work (delayed_work_timer_fn)
8D, 6082 kworker/0:0 queue_delayed_work (delayed_work_timer_fn)
4D, 6082 kworker/0:0 queue_delayed_work (delayed_work_timer_fn)
8, 12895 icedove-bin hrtimer_start_range_ns (hrtimer_wakeup)
4, 3516 udisks-daemon hrtimer_start_range_ns (hrtimer_wakeup)
4, 2642 hald-addon-stor hrtimer_start_range_ns (hrtimer_wakeup)
8, 7540 icedove-bin hrtimer_start_range_ns (hrtimer_wakeup)
8, 7777 icedove-bin hrtimer_start_range_ns (hrtimer_wakeup)
9, 0 kworker/0:0 hrtimer_start (tick_sched_timer)
6, 2665 Xorg __mod_timer (i915_hangcheck_elapsed)
8, 7550 icedove-bin hrtimer_start_range_ns (hrtimer_wakeup)
8, 3531 gvfs-afc-volume hrtimer_start_range_ns (hrtimer_wakeup)
7, 7551 icedove-bin hrtimer_start_range_ns (hrtimer_wakeup)
7, 7549 icedove-bin hrtimer_start_range_ns (hrtimer_wakeup)
7, 7578 icedove-bin hrtimer_start_range_ns (hrtimer_wakeup)
1, 0 swapper __mod_timer (uhci_fsbr_timeout)
7, 7527 icedove-bin hrtimer_start_range_ns (hrtimer_wakeup)
7, 12890 icedove-bin hrtimer_start_range_ns (hrtimer_wakeup)
7, 7536 icedove-bin hrtimer_start_range_ns (hrtimer_wakeup)
18, 12790 sakura hrtimer_start_range_ns (hrtimer_wakeup)
4, 3582 sensors-applet hrtimer_start_range_ns (hrtimer_wakeup)
4, 0 swapper __mod_timer (laptop_mode_timer_fn)
4, 0 swapper __mod_timer (dev_watchdog)
11, 2868 tor __mod_timer (process_timeout)
5, 7528 icedove-bin hrtimer_start_range_ns (hrtimer_wakeup)
4, 4807 dropbox hrtimer_start_range_ns (hrtimer_wakeup)
1, 12537 http __mod_timer (tcp_write_timer)
5, 2825 nmbd hrtimer_start_range_ns (hrtimer_wakeup)
1, 3439 gconfd-2 hrtimer_start_range_ns (hrtimer_wakeup)
4, 7403 kbnepd bnep0 __mod_timer (tcp_delack_timer)
1, 3422 ssh-agent hrtimer_start_range_ns (hrtimer_wakeup)
1, 2195 hald hrtimer_start_range_ns (hrtimer_wakeup)
1, 2195 hald __mod_timer (process_timeout)
1, 7 watchdog/0 hrtimer_start (watchdog_timer_fn)
1, 3444 gnome-power-man hrtimer_start_range_ns (hrtimer_wakeup)
3, 816 flush-8:0 __mod_timer (blk_unplug_timeout)
1, 1 init hrtimer_start_range_ns (hrtimer_wakeup)
1, 1 swapper enqueue_task_rt (sched_rt_period_timer)
16, 12790 sakura queue_delayed_work (delayed_work_timer_fn)
14, 12791 bash queue_delayed_work (delayed_work_timer_fn)
5, 2665 Xorg hrtimer_start_range_ns (hrtimer_wakeup)
2, 3582 sensors-applet __mod_timer (process_timeout)
1, 3569 gnome-volume-ma hrtimer_start_range_ns (hrtimer_wakeup)
1, 2247 NetworkManager hrtimer_start_range_ns (hrtimer_wakeup)
1D, 6082 kworker/0:0 queue_delayed_work (delayed_work_timer_fn)
1, 7403 kbnepd bnep0 __mod_timer (tcp_delack_timer)
1, 2642 hald-addon-stor __mod_timer (blk_rq_timed_out_timer)
1, 4804 dropbox __mod_timer (tcp_write_timer)
1, 3511 gnome-panel hrtimer_start_range_ns (hrtimer_wakeup)
2772 total events, 354.113 events/sec
Hope you can do something with it!
Let me know if I should do more testing.
Best wishes
Norbert
------------------------------------------------------------------------
Norbert Preining preining@{jaist.ac.jp, logic.at, debian.org}
JAIST, Japan TeX Live & Debian Developer
DSA: 0x09C5B094 fp: 14DF 2E6C 0307 BE6D AD76 A9C0 D2BF 4AA3 09C5 B094
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