Hi
Why is it that my DMA performance under the kernel 2.4.x is worse than the
one under 2.2? I have attached the stats below the mail- information and test
results under both kernels.
I use the following option under rc to set dma ;
/sbin/hdparm -c1 -d1 -m16 -X66 /dev/hda
I use resierfs, Iam disappointed that 2.4 results are about 1/3rd and need to
know if I have to tune something or add some kernel compilation option.
I only know that I have not turned on Raid on kernel 2.4 which is on in 2.2.
I thought it was not reqd with one hdd - could it be the cause. Any other
option relating to HDDs?
Anybody with similair results?
Thanks for your time.
Ashwin
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TEST RESULTS
___________________________
a) Kernel 2.2
(i) hdpartm -i:
/dev/hda:
Model=ST38420A, FwRev=3.07, SerialNo=7AZ0PTZT
Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs RotSpdTol>.5% }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=0
BuffType=unknown, BuffSize=512kB, MaxMultSect=16, MultSect=16
CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=16841664
IORDY=on/off, tPIO={min:240,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes: pio0 pio1 pio2 pio3 pio4
DMA modes: mdma0 mdma1 mdma2 udma0 udma1 *udma2
(ii) hdpartm -t:
/dev/hda:
Timing buffered disk reads: 64 MB in 4.38 seconds = 14.61 MB/sec
b) Kernel 2.4.1
(i) hdparm -i
/dev/hda:
Model=ST38420A, FwRev=3.07, SerialNo=7AZ0PTZT
Config={ HardSect NotMFM HdSw>15uSec Fixed DTR>10Mbs RotSpdTol>.5% }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=0
BuffType=unknown, BuffSize=512kB, MaxMultSect=16, MultSect=16
CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=16841664
IORDY=on/off, tPIO={min:240,w/IORDY:120}, tDMA={min:120,rec:120}
PIO modes: pio0 pio1 pio2 pio3 pio4
DMA modes: mdma0 mdma1 mdma2 udma0 udma1 *udma2
(ii) hdparm -t
/dev/hda:
Timing buffered disk reads: 64 MB in 11.61 seconds = 5.51 MB/sec
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