Dotaz: vysoky iowait

[Martin Ždila]

Nazdar

Pouzival som kernel 2.6.11.12 a nemal som nizsiespominany problem. Potom som skusil 2.6.12, potom 2.6.13 a nakoniec s ck1 patchom. U vsetkych tychto kernelov je pocitac hrozne pomaly, ked pracuje s diskom. Ked dam hdparm -t a hdparm -T tak priepustnost HDD vyzera ok:

root@martin:~# hdparm -t /dev/hda

/dev/hda:
 Timing buffered disk reads:  110 MB in  3.03 seconds =  36.29 MB/sec
root@martin:~# hdparm -T /dev/hda

/dev/hda:
 Timing cached reads:   1164 MB in  2.01 seconds = 580.06 MB/sec

Problem je, ze pri praci s diskom je vysoke iowait (zozerie co najviac CPU):

...
Time: 18:15:06
avg-cpu:  %user   %nice %system %iowait   %idle
           0.98    0.00    1.96   97.06    0.00

Time: 18:15:07
avg-cpu:  %user   %nice %system %iowait   %idle
          19.19    0.00    3.03   77.78    0.00
...

Parametre disku su tiez ok:

root@martin:~# hdparm -d /dev/hda

/dev/hda:
 using_dma    =  1 (on)


root@martin:~# hdparm -i /dev/hda

/dev/hda:

 Model=Maxtor 5T040H4, FwRev=TAH71DP0, SerialNo=T4HMZYBC
 Config={ Fixed }
 RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=57
 BuffType=DualPortCache, BuffSize=2048kB, MaxMultSect=16, MultSect=off
 CurCHS=4047/16/255, CurSects=16511760, LBA=yes, LBAsects=80043264
 IORDY=on/off, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120}
 PIO modes:  pio0 pio1 pio2 pio3 pio4 
 DMA modes:  mdma0 mdma1 mdma2 
 UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5 
 AdvancedPM=yes: disabled (255) WriteCache=disabled
 Drive conforms to: ATA/ATAPI-6 T13 1410D revision 0: 

 * signifies the current active mode

V logoch kernelu (dmesg) nevidim ziaden problem. Prosim, dajte mi nejaky tip, ako najst problem a ako ho odstranit.

Vopred vdaka! Martin

Odpovědi

[tomas84]

Používat jádro z Vaší distribuce, které učtitě bude odladěné a funkční...

[Martin Ždila]

no to je linux from scratch. ziadna konkretna distribucia