[OM2008/testing] "HZ" is wrong?

[Vasco Névoa]

Just a note: yesterday, when I started debugging this, the system WAS  
pretty much idle while unzipping.
Today's 30% CPU usage by "events/0" definitely looks like #1587.

Citando Vasco Névoa <vasco.nevoa at sapo.pt>:

>
> Hi.
> I've started unzipping the "Hackable:1" tarball inside the GTA02  
> about 20 hours ago, and it is still going on.
> It's sitting on an ext2 uSD partition and extracting into another.
> The funny thing is, when I pull up "top", it mostly shows an idle  
> system (see below). The CPU is mostly idle, and in fact I can do  
> everything else at the same time very easily.
> So the big question is: what the heck is locking up the tar process?
> One thing that makes me suspicious of the kernel is the warning  
> printed by "top": "Unknown HZ value! (6) Assume 100." (and yesterday  
> it reported (5) instead of (6)...)
>
> How can I debug this further?
>
> root at om-gta02:~# uname -a
> Linux om-gta02 2.6.24 #1 PREEMPT Wed Dec 10 09:19:15 CST 2008 armv4tl unknown
>
> root at om-gta02:~# top
> Unknown HZ value! (6) Assume 100.
> top - 08:24:55 up 19:57,  3 users,  load average: 2.66, 2.53, 2.54
> Tasks:  71 total,   2 running,  69 sleeping,   0 stopped,   0 zombie
> Cpu(s):  5.4%us, 27.7%sy,  0.0%ni,  0.0%id, 66.1%wa,  0.9%hi,   
> 0.0%si,  0.0%st
> Mem:    126260k total,   124132k used,     2128k free,      792k buffers
> Swap:        0k total,        0k used,        0k free,    54952k cached
>
>   PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+  COMMAND
>     5 root      15  -5     0    0    0 R 21.3  0.0  22:38.62 events/0
> 25150 root      20   0  2252 1112  892 R  8.0  0.9   0:00.82 top
>   259 root      15  -5     0    0    0 D  1.8  0.0   1:23.08 SDIO Helper
>   276 root      15  -5     0    0    0 D  1.8  0.0   6:45.12 mmcqd
>  1206 root      19  -1 18260  10m 1936 S  0.9  8.8  21:25.39 Xglamo
> 25141 root      20   0  2264 1048  724 S  0.9  0.8   0:00.71 dropbear
>     1 root      20   0  1524  564  500 S  0.0  0.4   0:05.41 init
>     2 root      15  -5     0    0    0 S  0.0  0.0   0:00.00 kthreadd
>     3 root      15  -5     0    0    0 S  0.0  0.0   0:00.00 ksoftirqd/0
>     4 root      RT  -5     0    0    0 S  0.0  0.0   0:00.00 watchdog/0
>     6 root      15  -5     0    0    0 S  0.0  0.0   0:00.06 khelper
>    70 root      15  -5     0    0    0 S  0.0  0.0   0:00.00 kblockd/0
>    76 root      15  -5     0    0    0 S  0.0  0.0   0:00.00 ksuspend_usbd
>    82 root      15  -5     0    0    0 S  0.0  0.0   0:00.00 khubd
>    85 root      15  -5     0    0    0 S  0.0  0.0   0:00.00 kseriod
>    91 root      15  -5     0    0    0 S  0.0  0.0   0:00.01 kmmcd
>   123 root      20   0     0    0    0 S  0.0  0.0   0:00.00 pdflush
>   124 root      20   0     0    0    0 S  0.0  0.0   0:00.26 pdflush
>   125 root      15  -5     0    0    0 S  0.0  0.0   0:02.18 kswapd0
>   126 root      15  -5     0    0    0 S  0.0  0.0   0:00.00 aio/0
>   142 root      15  -5     0    0    0 S  0.0  0.0   0:00.00 kapmd
>   174 root      15  -5     0    0    0 S  0.0  0.0   0:00.00 glamo-spi-gpio.
>   184 root      15  -5     0    0    0 S  0.0  0.0   0:00.00 mtdblockd
>   255 root      15  -5     0    0    0 S  0.0  0.0   0:00.21 SDIO Helper
>   270 root      15  -5     0    0    0 S  0.0  0.0   0:00.00 rpciod/0
>   275 root      30  10     0    0    0 S  0.0  0.0   0:25.48 jffs2_gcd_mtd6
>   345 root      16  -4  1860  612  388 S  0.0  0.5   0:01.16 udevd
>  1092 root      10 -10     0    0    0 S  0.0  0.0   0:00.00 krfcommd
>
> Thanks,
> Vasco.