GLANTANK の dma パッチあたった kernel

debian

岩松さんに教えてもらったので試してみるテスト

どーだろう...

  • DMA パッチのあたっていない(lenny official) kernel の場合
$ hdparm -vtT
/dev/hda:
 multcount     =  0 (off)
 IO_support    =  0 (default)
 unmaskirq     =  0 (off)
 using_dma     =  1 (on)
 keepsettings  =  0 (off)
 readonly      =  0 (off)
 readahead     = 256 (on)
 geometry      = 19457/255/63, sectors = 312581808, start = 0
 Timing cached reads:   128 MB in  2.03 seconds =  63.19 MB/sec
 Timing buffered disk reads:   96 MB in  3.03 seconds =  31.73 MB/sec
  • DMA パッチのあたった kernel の場合
$ hdparm -vtT
/dev/hda:
 multicount     =  0 (off)
 IO_support    =  0 (default)
 unmaskirq     =  0 (off)
 using_dma     =  1 (on)
 keepsettings  =  0 (off)
 readonly      =  0 (off)
 readahead     = 256 (on)
 geometry      = 19457/255/63, sectors = 312581808, start = 0
 Timing cached reads:   296 MB in  2.00 seconds = 148.10 MB/sec
 Timing buffered disk reads:  142 MB in  3.04 seconds =  46.74 MB/sec

cached reads が倍ぐらいになった. とりあえずこれで行ってみよう