Re: 'D' processes on a healthy system?

From: martin f krafft (madduck@debian.org)
Date: Tue Jan 07 2003 - 03:01:35 EST


also sprach Alan Cox <alan@lxorguk.ukuu.org.uk> [2002.12.19.2027 +0100]:
> Its more to do with the controller and configuration. Eg if your disk
> isnt in DMA mode it'll certainly show up

i know took the system offline to test a little more. the harddrive is
operating fine without errors. i defined runlevel 4 to be single user
mode + sshd, now the system is running 14 processes including the
kernel processes.

hdparm shows this for /dev/hda:

/dev/hda:
 multcount = 16 (on)
 I/O support = 1 (32-bit)
 unmaskirq = 1 (on)
 using_dma = 1 (on)
 keepsettings = 0 (off)
 nowerr = 0 (off)
 readonly = 0 (off)
 readahead = 8 (on)
 geometry = 2491/255/63, sectors = 40021632, start = 0
 busstate = 1 (on)

correct me if i am wrong, but it is properly tweaked. moreover, lspci
shows that there is a VT82C598 [Apollo MVP3] VIA Chipset in there, and
my kernel config is optimized for that:

  CONFIG_BLK_DEV_IDEPCI=y
  CONFIG_IDEPCI_SHARE_IRQ=y
  CONFIG_BLK_DEV_IDEDMA_PCI=y
  CONFIG_IDEDMA_PCI_AUTO=y
  CONFIG_BLK_DEV_IDEDMA=y
  CONFIG_BLK_DEV_ADMA=y
  CONFIG_BLK_DEV_VIA82CXXX=y
  CONFIG_IDEDMA_AUTO=y
  CONFIG_BLK_DEV_IDE_MODES=y

Nevertheless, with 14 processes running and none of them accessing
the disk, i started an rsync process over ssh for the home partition.
and performance is ridiculous. rsync will transfer about 40k before
the rsync process enters 'D' state as shown by top. this takes about
10 seconds, then rsync gets to transfer another 40k.

this is on an AMD K6-2 500 MHz machine with 160 Mb RAM, 256Mb of swap
and a Maxtor 10Gb drive spinning at 5,400 I believe.

What's the problem?

-- 
Please do not CC me! Mutt (www.mutt.org) can handle this automatically.
 
 .''`.     martin f. krafft <madduck@debian.org>
: :'  :    proud Debian developer, admin, and user
`. `'`
  `-  Debian - when you have better things to do than fixing a system
 
NOTE: The pgp.net keyservers and their mirrors are broken!
Get my key here: http://people.debian.org/~madduck/gpg/330c4a75.asc


- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/



This archive was generated by hypermail 2b29 : Tue Jan 07 2003 - 22:00:34 EST