Re: Odd IDE performance drop 2.4 vs 2.6?

From: Grant Coady
Date: Mon Jun 13 2005 - 13:15:43 EST


On Mon, 13 Jun 2005 14:39:37 +0100, Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote:

>On Llu, 2005-06-13 at 11:43, Ondrej Zary wrote:
>> I see this problem too with i430TX chipset (the south bridge and thus
>> IDE controller is the same as in i440LX/EX and BX/ZX).
>
>Make sure you have pre-empt disabled and the antcipatory I/O scheduler
>disabled.
I don't set pre-empt, not sure about scheduler, recheck that in daytime,
SATA (Via chipset) on different box doesn't have the problem, neither
another box with SATA and ICH5, this is Via chipset, two runs after boot:

Linux 2.4.31-sp

root@sempro:~# hdparm -tT /dev/sda

/dev/sda:
Timing cached reads: 1172 MB in 2.00 seconds = 586.00 MB/sec
HDIO_DRIVE_CMD(null) (wait for flush complete) failed: Inappropriate ioctl for device
Timing buffered disk reads: 172 MB in 3.02 seconds = 56.95 MB/sec
HDIO_DRIVE_CMD(null) (wait for flush complete) failed: Inappropriate ioctl for device
root@sempro:~# hdparm -tT /dev/sda

/dev/sda:
Timing cached reads: 1056 MB in 2.00 seconds = 528.00 MB/sec
HDIO_DRIVE_CMD(null) (wait for flush complete) failed: Inappropriate ioctl for device
Timing buffered disk reads: 170 MB in 3.00 seconds = 56.67 MB/sec
HDIO_DRIVE_CMD(null) (wait for flush complete) failed: Inappropriate ioctl for device
root@sempro:~#

Linux 2.6.11.12a

/dev/sda:
Timing cached reads: 1308 MB in 2.00 seconds = 653.77 MB/sec
HDIO_DRIVE_CMD(null) (wait for flush complete) failed: Inappropriate ioctl for device
Timing buffered disk reads: 170 MB in 3.00 seconds = 56.60 MB/sec
HDIO_DRIVE_CMD(null) (wait for flush complete) failed: Inappropriate ioctl for device
root@sempro:~# hdparm -tT /dev/sda

/dev/sda:
Timing cached reads: 1124 MB in 2.00 seconds = 560.96 MB/sec
HDIO_DRIVE_CMD(null) (wait for flush complete) failed: Inappropriate ioctl for device
Timing buffered disk reads: 170 MB in 3.00 seconds = 56.66 MB/sec
HDIO_DRIVE_CMD(null) (wait for flush complete) failed: Inappropriate ioctl for device
root@sempro:~#

HDD specified as 58MB/s at the fast end, so these figures look reasonable.
http://scatter.mine.nu/test/boxen/sempro/ for hardware / config info

--Grant.

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