DMA with current 2.4.x kernels

[Ralph Siemsen]

François Jacques wrote:

> My guess was right.

Just for fun I collected some stats from the autobuilder machines. 
These all run 2.4.19-rmk7-nw1 kernel currently.

The ability to do DMA depends on version of '553 chip.
Furthermore, most Rev5 netwinders use the newer chip.

Node 1:   128  5a7f  10   1 (on)    12.34  QUANTUM FIREBALLlct10 10
Node 2:   128  567f  10   1 (on)    12.90  QUANTUM FIREBALLlct10 10
Node 3:   64   52ff  05   0 (off)    3.70  TOSHIBA MK4006MAV
Node 4:   64   52ff  10   1 (on)     6.15  TOSHIBA MK4006MAV
Node 5:   64   56ff  10   1 (on)     5.79  TOSHIBA MK4006MAV
Node 6:   64   42ff  05   0 (off)    2.60  HITACHI_DK229A-10
Node 7:   64   44ff  05   0 (off)    4.11  HITACHI_DK238A-43
Node 8:   128  52ff  05   0 (off)    3.67  HITACHI_DK229A-10
Node 9:   128  52ff  10   1 (on)     8.97  HITACHI_DK229A-10
Node 10:  64   52ff  10   1 (on)     7.74  HITACHI_DK238A-43
Node 11:  64   52ff  10   1 (on)     6.15  TOSHIBA MK4006MAV
Node 12:  64   60ff  10   1 (on)     5.81  TOSHIBA MK4006MAV

Where the data came from:
Revision as reported by /proc/cpuinfo
553 revision from lspci output (ISA bridge)
UsingDMA from ouput of hdparm /dev/hda
Speed report is MB/sec from hdparm -tT /dev/hda
Drive model from /proc/ide/ide0/hda/model

Nodes1 and 2 are rackmounts with 3.5" drives, all others use 2.5" 
drives. There is a considerable speed difference as you can clearly see.

-R