Hello
I have 2.8 GHz Pentium IV with 1GB RAM and 250GB ATA-133 IDE disk
on /dev/hdb.
I did cat /dev/hdb > /dev/null and after a while (5 minutes),
the system went totally unresponsive:
1) man top takes 3 minutes to display man page
2) Switching between console and X takes also a couple of minutes
3) top shows this:
Cpu(s): 1.4% us, 1.4% sy, 0.0% ni, 0.0% id, 0.0% wa, 97.3% hi, 0.0% si
/dev/hdb is auxilliary disk that is not used, is not mounted and the
root filesystem doesn't reside on it (of course). Kernel version is 2.6.3.
Is this behaviour normal?
Cl<
> I did cat /dev/hdb > /dev/null and after a while (5 minutes),
> the system went totally unresponsive:
>
> 1) man top takes 3 minutes to display man page
> 2) Switching between console and X takes also a couple of minutes
> 3) top shows this:
>
> Cpu(s): 1.4% us, 1.4% sy, 0.0% ni, 0.0% id, 0.0% wa, 97.3% hi, 0.0% si
i guess you have DMA enabled on /dev/hdb. I would expect, that the
system is at least 50% idle
> i guess you have DMA enabled on /dev/hdb. I would expect, that the
> system is at least 50% idle
i did
dd if=/dev/hda of=/dev/null bs=1M
and noticed, that top shows 0% idle, but 95% wa - what ever that means.
Since i've got DMA turned on, i would expect the CPU to be 95% idle,
instead 95% wa? what does "wa" stand for?
On Friday 09 April 2004 03:10, Sven K?hler wrote:
> > i guess you have DMA enabled on /dev/hdb. I would expect, that the
> > system is at least 50% idle
>
> i did
> dd if=/dev/hda of=/dev/null bs=1M
> and noticed, that top shows 0% idle, but 95% wa - what ever that means.
>
> Since i've got DMA turned on, i would expect the CPU to be 95% idle,
> instead 95% wa? what does "wa" stand for?
top version? Mine is 2.0.18, looks like this:
09:47:25 up 1 day, 17:07, 2 users, load average: 0.42, 0.27, 0.24
116 processes: 114 sleeping, 2 running, 0 zombie, 0 stopped
CPU states: 4.2% user 52.1% system 0.0% nice 43.6% iowait 0.0% idle
Mem: 122736k av, 121088k used, 1648k free, 0k shrd, 22968k buff
76324k active, 21000k inactive
Swap: 76792k av, 67004k used, 9788k free 25748k cached
PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME CPU COMMAND
15022 root 18 0 2280 1460 1200 R 38.6 1.1 0:05 0 dd
--
vda