Sziasztok!

Nekem is dma problémám van.
Egy live cd vel bebootolva 217 MB/s es ( Timing cached reads)értéket produkál a masina, szemben a telepített gentoo-val:

engepem roland # hdparm -d0 /dev/hda

/dev/hda:
setting using_dma to 0 (off)
using_dma =  0 (off)
engepem roland # hdparm -tT /dev/hda

/dev/hda:
Timing cached reads:  216 MB in  2.02 seconds = 107.18 MB/sec
Timing buffered disk reads:    8 MB in  3.39 seconds =  2.36 MB/sec
engepem roland # hdparm -d1 /dev/hda

/dev/hda:
setting using_dma to 1 (on)
using_dma =  1 (on)
engepem roland # hdparm -tT /dev/hda

/dev/hda:
Timing cached reads:  214 MB in  2.01 seconds = 106.42 MB/sec
Timing buffered disk reads:  72 MB in  3.03 seconds =  23.76 MB/sec
engepem roland #

Mi lehet a baj?

Így csináltam kb a dma-t: http://gentoo-wiki.com/HARDWARE_DMA_and_you
Merre fele kutassak, vagy mit lenne érdemes ide bemásolni?

A chipsetem VIA-s, és ez is van beállítva a kernelbe, illetve ennél a résznél még  „Intel PIIXn chipsets support ” mert az olvastam annaki mindig be kéne lennie jelölve.

— ATA/ATAPI/MFM/RLL support   │ │ 
  │ │     Enhanced IDE/MFM/RLL disk/cdrom/tape/floppy support │ │ 
  │ │   — Please see Documentation/ide.txt for help/info on IDE drives     │ │ 
  │ │   [ ] Support for SATA (deprecated; conflicts with libata SATA driver) │ │ 
  │ │   [ ] Use old disk-only driver on primary interface     │ │ 
  │ │   Include IDE/ATA-2 DISK support     │ │ 
  │ │  
[*] Use multi-mode by default     │ │ 
  │ │   Include IDE/ATAPI CDROM support   │ │ 
  │ │   Include IDE/ATAPI TAPE support (EXPERIMENTAL)     │ │ 
  │ │   Include IDE/ATAPI FLOPPY support   │ │ 
  │ │   SCSI emulation support   │ │ 
  │ │   [ ] IDE ACPI support   │ │ 
  │ │   [ ] IDE Taskfile Access │ │ 
  │ │  
[*] legacy /proc/ide/ support     │ │ 
  │ │   — IDE chipset support/bugfixes │ │ 
  │ │   generic/default IDE chipset support     │ │ 
  │ │   [ ] CMD640 chipset bugfix/support │ │ 
  │ │   [ ] PNP EIDE support   │ │ 
  │ │  
[*] PCI IDE chipset support │ │ 
  │ │   [ ]   Sharing PCI IDE interrupts support   │ │ 
  │ │   [ ] Boot off-board chipsets first support   │ │ 
  │ │   Generic PCI IDE Chipset Support   │ │ 
  │ │   OPTi 82C621 chipset enhanced support (EXPERIMENTAL)   │ │ 
  │ │   RZ1000 chipset bugfix/support │ │ 
  │ │  
[*] Generic PCI bus-master DMA support │ │ 
  │ │   [ ]   Force enable legacy 2.0.X HOSTS to use DMA │ │ 
  │ │   [ ]   Enable DMA only for disks   │ │ 
  │ │     AEC62XX chipset support     │ │ 
  │ └─────────────────v(+)───────────────────────────────────────────────────────────────────────────────────┘ │ 
  ├──────────────────────────────────────────────────────────────────────────────

A VIA fixen benne van, így gondolom nem kell a modult betölteni.
  VIA82CXXX chipset support

engepem roland # lspci
00:00.0 Host bridge: VIA Technologies, Inc. VT8363/8365 [KT133/KM133] (rev 03)
00:01.0 PCI bridge: VIA Technologies, Inc. VT8363/8365 [KT133/KM133 AGP]
00:07.0 ISA bridge: VIA Technologies, Inc. VT82C686 [Apollo Super South] (rev 40)
00:07.1 IDE interface: VIA Technologies, Inc. VT82C586A/B/VT82C686/A/B/VT823x/A/C PIPC Bus Master IDE (rev 06)
00:07.2 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 16)
00:07.3 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 16)
00:07.4 Host bridge: VIA Technologies, Inc. VT82C686 [Apollo Super ACPI] (rev 40)
00:08.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8029(AS)
00:09.0 Multimedia audio controller: Creative Labs SB Live! EMU10k1 (rev 06)
00:09.1 Input device controller: Creative Labs SB Live! Game Port (rev 06)
00:0d.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL-8139/8139C/8139C+ (rev 10)
00:0f.0 Multimedia video controller: Brooktree Corporation Bt878 Video Capture (rev 11)
00:0f.1 Multimedia controller: Brooktree Corporation Bt878 Audio Capture (rev 11)
00:13.0 Mass storage controller: HighPoint Technologies, Inc. HPT366/368/370/370A/372/372N (rev 04)
01:00.0 VGA compatible controller: nVidia Corporation NV17 [GeForce4 MX 440] (rev a3)

Kiszedtem a VIA-t beraktam a HPT-t, újrafordítottam. Nem működik. Így már a dma-t se lehet bekapcsolni:

engepem linux # hdparm -d1 /dev/hda

/dev/hda:
setting using_dma to 1 (on)
HDIO_SET_DMA failed: Operation not permitted
using_dma =  0 (off)

Egyébként a sebesség ugyanaz.

gentoo

engepem roland # hdparm -i /dev/hda

/dev/hda:

Model=Maxtor 6Y080L0, FwRev=YAR41BW0, SerialNo=Y2VGWT4E
Config={ Fixed }
RawCHS=16383/16/63, TrkSize=0, SectSize=0, ECCbytes=57
BuffType=DualPortCache, BuffSize=2048kB, MaxMultSect=16, MultSect=16
CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=160086528
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 udma6
AdvancedPM=yes: disabled (255) WriteCache=enabled
Drive conforms to: ATA/ATAPI-7 T13 1532D revision 0:  ATA/ATAPI-1,2,3,4,5,6,7

* signifies the current active mode