On Wed, Sep 05, 2001 at 04:13:00PM -0400, Norbert Veber wrote:
> On Sat, Sep 01, 2001 at 12:12:46PM +1000, Craig Sanders wrote:
> > On Sat, Sep 01, 2001 at 11:35:05AM +1000, Brian May wrote:
> > > Also, if a computer is running slowly, but top says the CPU has plenty
> > > of idle time and free RAM, is there anyway I can find out what is
> > > wrong?
> >
> > most likely slow disks.
>
> Your system is supposed to multitask regardless if your disks are slow or
> not. Unfortunatelly the default settings are quite conservative and give
> very bad performance via older disks.
>
> Try reading man hdparm. The most useful setting is enabling DMA (which
> needs additional kernel support for your chipset), there is also the unmask
> irq setting which lets your machine (somehow) process other interrupts while
> waiting for disk IO, and the 32-bit access.
>
> This however can lead to data corruption on crappy hardware, so test
> thoughtly before making the change long-term..
Thanks for the tip. It sounds exactly like my problem: system runs extremely
slowly
while find runs in the background. This was when find was searching
/usr/src/kernel-source-2.2.8,
which is not NFS
Unfortunately, this system already has DMA enabled by default:
/dev/hda:
multcount = 16 (on)
I/O support = 0 (default 16-bit)
unmaskirq = 0 (off)
using_dma = 1 (on)
keepsettings = 0 (off)
nowerr = 0 (off)
readonly = 0 (off)
readahead = 8 (on)
geometry = 1247/255/63, sectors = 20044080, start = 0
pluto:~# hdparm /dev/hdb
/dev/hdb:
multcount = 16 (on)
I/O support = 0 (default 16-bit)
unmaskirq = 0 (off)
using_dma = 1 (on)
keepsettings = 0 (off)
nowerr = 0 (off)
readonly = 0 (off)
readahead = 8 (on)
geometry = 1871/255/63, sectors = 30064608, start = 0
top says:
16:38:03 up 13 min, 1 user, load average: 1.71, 1.40, 0.70
91 processes: 88 sleeping, 2 running, 1 zombie, 0 stopped
CPU states: 7.8% user, 34.0% system, 2.9% nice, 55.3% idle
Mem: 126564K total, 123764K used, 2800K free, 38828K buffers
Swap: 497972K total, 59796K used, 438176K free, 11732K cached
PID USER PRI NI SIZE RSS SHARE STAT %CPU %MEM TIME COMMAND
2170 root 19 10 224 132 132 R N 10.0 0.1 0:04 find
2193 root 17 0 920 912 700 R 6.7 0.7 0:00 top
632 jan 15 0 17460 11M 11168 S 5.8 9.0 0:10 mozilla-bin
and I don't think you can really say that this is a slow computer either:
pluto:/proc/2170# cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 6
model name : Celeron (Mendocino)
stepping : 5
cpu MHz : 434.327
cache size : 128 KB
fdiv_bug : no
hlt_bug : no
f00f_bug : no
coma_bug : no
fpu : yes
fpu_exception : yes
cpuid level : 2
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pat
pse36 mmx fxsr
bogomips : 865.07
Bootup harddisk information:
Uniform Multi-Platform E-IDE driver Revision: 6.31
ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
PIIX4: IDE controller on PCI bus 00 dev f9
PIIX4: chipset revision 1
PIIX4: not 100% native mode: will probe irqs later
ide0: BM-DMA at 0xf000-0xf007, BIOS settings: hda:DMA, hdb:DMA
ide1: BM-DMA at 0xf008-0xf00f, BIOS settings: hdc:pio, hdd:DMA
hda: WDC WD102AA, ATA DISK drive
hdb: WDC WD153AA, ATA DISK drive
hdd: MATSHITADVD-ROM SR-8583A, ATAPI CD/DVD-ROM drive
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
ide1 at 0x170-0x177,0x376 on irq 15
hda: 20044080 sectors (10263 MB) w/2048KiB Cache, CHS=1247/255/63, UDMA(66)
hdb: 30064608 sectors (15393 MB) w/2048KiB Cache, CHS=1871/255/63, UDMA(66)
Partition check:
/dev/ide/host0/bus0/target0/lun0: p1 p2 < p5 p6 p7 >
/dev/ide/host0/bus0/target1/lun0: p1 p2 < p5 p6 p7 >
8139too Fast Ethernet driver 0.9.18
So I can only conclude that something is very odd with this computer, but I
don't know
what.
--
Brian May <[EMAIL PROTECTED]>
