Re: [ANNOUNCE] 4.4-rc6-rt1

[Mike Galbraith]

On Thu, 2015-12-31 at 10:24 -0600, Clark Williams wrote:

> I pulled this update and tried it on my laptop (i7 quad-core with HT)
> and an Atom testbox. I'm seeing a change in the cpu utilization of
> ksoftirqd between 4.1.15-rt17 and 4.4-rc2-rt1, where the per-cpu
> ksoftirqd threads are running at between 25-40% utilization:
> 
> top - 10:15:57 up 13:46,  2 users,  load average: 9.44, 9.30, 8.93
> Tasks: 188 total,   2 running, 186 sleeping,   0 stopped,   0 zombie
> %Cpu(s):  4.7 us, 53.6 sy,  0.0 ni, 37.4 id,  0.1 wa,  0.0 hi,  4.2 si,  0.0 st
> KiB Mem :  4046064 total,   480548 free,   179528 used,  3385988 buff/cache
> KiB Swap:  5177340 total,  5169908 free,     7432 used.  3785624 avail Mem 
> 
>   PID USER      PR  NI    VIRT    RES    SHR S  %CPU %MEM     TIME+ COMMAND                      
>     3 root      -2   0       0      0      0 S  37.3  0.0 307:52.44 ksoftirqd/0                  
>    32 root      -2   0       0      0      0 S  37.3  0.0 308:08.72 ksoftirqd/2                  
>    42 root      -2   0       0      0      0 R  37.3  0.0 308:32.84 ksoftirqd/3                  
>    22 root      -2   0       0      0      0 S  26.9  0.0 222:29.82 ksoftirqd/1                  
>     1 root      20   0   46628   6980   4976 S   1.3  0.2   0:13.98 systemd                      
> 22358 williams  20   0  159980   4552   3780 R   1.0  0.1   0:00.39 top       

Heh, I didn't notice immediately because I throttle nohz, am seeing
only tiny utilization (but nohz idle isn't working).  With throttle
patch removed, box is screaming, expires=4294990471 pokes eyeball.

         swapper     0 [003]   392.708321: timer:hrtimer_cancel: hrtimer=0xffff88041ecce720
         swapper     0 [003]   392.708321: timer:hrtimer_start: hrtimer=0xffff88041ecce720 function=tick_sched_timer/0x0 expires=4294990471 softexpires=4294990471
         swapper     0 [003]   392.708323: timer:hrtimer_cancel: hrtimer=0xffff88041ecce720
         swapper     0 [003]   392.708324: timer:hrtimer_expire_entry: hrtimer=0xffff88041ecce720 now=392697118535 function=tick_sched_timer/0x0
         swapper     0 [003]   392.708325: timer:hrtimer_expire_exit: hrtimer=0xffff88041ecce720
         swapper     0 [003]   392.708326: timer:hrtimer_start: hrtimer=0xffff88041ecce720 function=tick_sched_timer/0x0 expires=392700750000 softexpires=392700750000
         swapper     0 [003]   392.708328: timer:tick_stop: success=yes msg=
         swapper     0 [003]   392.708329: timer:hrtimer_cancel: hrtimer=0xffff88041ecce720
         swapper     0 [003]   392.708329: timer:hrtimer_start: hrtimer=0xffff88041ecce720 function=tick_sched_timer/0x0 expires=4294990471 softexpires=4294990471
         swapper     0 [003]   392.708331: timer:hrtimer_cancel: hrtimer=0xffff88041ecce720
         swapper     0 [003]   392.708332: timer:hrtimer_expire_entry: hrtimer=0xffff88041ecce720 now=392697126313 function=tick_sched_timer/0x0
         swapper     0 [003]   392.708333: timer:hrtimer_expire_exit: hrtimer=0xffff88041ecce720
         swapper     0 [003]   392.708334: timer:hrtimer_start: hrtimer=0xffff88041ecce720 function=tick_sched_timer/0x0 expires=392700750000 softexpires=392700750000
         swapper     0 [003]   392.708336: timer:tick_stop: success=yes msg=

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/