Machine's high load when HIGHMEM is enabled

vasya vasyaev
2002-11-03T14:11:24Z

Hello,

I have some strange kind of problem:
When HIGHMEM-enabled kernel is used, there is too high
CPU load on any task - computer get loaded high while
it is doing some minor, usual jobs (load average grows
significantly).
I don't know how to explain - everything is fine,
computer boots ok, there is no errors (warnings, etc.)
in logs, but as to compare, computer is working slower
that i386...
e.g.: 'gzip some_filename' takes about 5-7 times more
than on HIGHMEM-disabled kernel, ssh login to this
machine takes about 2-3 minutes (computing, disk
operations, network throughput)
I have tried different kernels from RH distro's and
updates:
kernel-2.4.18-17.7
kernel-2.4.18-10
kernel-2.4.18-5

machine has 2 processors, but using SMP/non-SMP
kernels does not matter (I've used both variants)

I have also compiled these kernels from source, and my
results are:
HIGHMEM-disabled kernels works fine, but they can see
only ~900 Mb of memory
the same kernels, but only with HIGHMEM=4G enabled has
such strange effect of high load.

I've also tried following kernels from RH:
kernel-enterprise-2.4.9-34
kernel-enterprise-2.4.9-33
kernel-enterprise-2.4.9-31
and effect is the same...

Any ideas ? need more info?

Here follows this computer configuration:

# lspci
00:00.0 Host bridge: Intel Corp. 440GX - 82443GX Host
bridge
00:01.0 PCI bridge: Intel Corp. 440GX - 82443GX AGP
bridge
00:07.0 ISA bridge: Intel Corp. 82371AB/EB/MB PIIX4
ISA (rev 02)
00:07.1 IDE interface: Intel Corp. 82371AB/EB/MB PIIX4
IDE (rev 01)
00:07.2 USB Controller: Intel Corp. 82371AB/EB/MB
PIIX4 USB (rev 01)
00:07.3 Bridge: Intel Corp. 82371AB/EB/MB PIIX4 ACPI
(rev 02)
00:0f.0 PCI bridge: Intel Corp. 80960RP [i960 RP
Microprocessor/Bridge] (rev 05)
00:0f.1 I2O: Intel Corp. 80960RP [i960RP
Microprocessor] (rev 05)
00:10.0 Ethernet controller: 3Com Corporation 3c905B
100BaseTX [Cyclone] (rev 64)
01:00.0 VGA compatible controller: ATI Technologies
Inc 3D Rage IIC AGP (rev 3a)

# cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 7
model name : Pentium III (Katmai)
stepping : 3
cpu MHz : 551.261
cache size : 32 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 apic sep
mtrr pge mca cmov pat pse36 mmx fxsr sse
bogomips : 1101.00

processor : 1
vendor_id : GenuineIntel
cpu family : 6
model : 7
model name : Pentium III (Katmai)
stepping : 3
cpu MHz : 551.261
cache size : 32 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 apic sep
mtrr pge mca cmov pat pse36 mmx fxsr sse
bogomips : 1101.00

# cat /proc/meminfo
total: used: free: shared: buffers:
cached:
Mem: 2100666368 80003072 2020663296 0 5554176
43016192
Swap: 1069277184 0 1069277184
MemTotal: 2051432 kB
MemFree: 1973304 kB
MemShared: 0 kB
Buffers: 5424 kB
Cached: 42008 kB
SwapCached: 0 kB
Active: 34376 kB
Inact_dirty: 13056 kB
Inact_clean: 0 kB
Inact_target: 522240 kB
HighTotal: 1171456 kB
HighFree: 1124452 kB
LowTotal: 879976 kB
LowFree: 848852 kB
SwapTotal: 1044216 kB
SwapFree: 1044216 kB

# lsmod
Module Size Used by Not tainted
3c59x 31976 1
reiserfs 181312 1
megaraid 27808 2
sd_mod 13756 2
scsi_mod 123524 2 [megaraid sd_mod]

binutils-2.11.93.0.2-11
gcc-2.96-112
glibc-2.2.5-40

Thanks in advance.

__________________________________________________
Do you Yahoo!?
HotJobs - Search new jobs daily now