Re: kernel performance problem
From: Walt H (walt_h_at_lorettotel.net)
Date: 09/11/05
- Previous message: Denis Vlasenko: "Re: [GIT PATCHES] final kbuild update before fix-only period"
- Maybe in reply to: Andrew Smith: "kernel performance problem"
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Date: Sun, 11 Sep 2005 07:29:45 -0500 To: asmith@vtrl.co.uk
>
>
>This is my first ever posting to this list, so please excuse me if I've
>f**cked up and broken protocol.
>I use an IDE LG DVD-RW drive for backup(GSA-4081B).
>Back around 2.6.10 it wrote at typically 1.6-1.7x speed, but thereafter
>it dropped to around 0.6-0.7 x.
>
>
>%hdparm -I /dev/hdd
>
>/dev/hdd:
>
>ATAPI CD-ROM, with removable media
> Model Number: HL-DT-ST DVDRAM GSA-4081B
> Serial Number: K2B3CFE4600
> Firmware Revision: A100
>Standards:
> Likely used CD-ROM ATAPI-1
>Configuration:
> DRQ response: 50us.
> Packet size: 12 bytes
>Capabilities:
> LBA, IORDY(can be disabled)
> DMA: mdma0 mdma1 mdma2 udma0 udma1 *udma2
> Cycle time: min=120ns recommended=120ns
> PIO: pio0 pio1 pio2 pio3 pio4
> Cycle time: no flow control=120ns IORDY flow control=120ns
>HW reset results:
> CBLID- below Vih
> Device num = 1
>
Hi Andrew,
I know that hdparm shows udma2 mode selected for data transfers, but
check that dma is *actually* turned on. ie: hdparm -d1 /dev/hdd
I don't remember exactly when this went in, but there were some IDE
patches around the 2.6.11 or so timeframe that seemed to change the way
these devices get setup at boot. I believe this happened when the
autotune= syntax was deprecated. HTH,
-Walt
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- Previous message: Denis Vlasenko: "Re: [GIT PATCHES] final kbuild update before fix-only period"
- Maybe in reply to: Andrew Smith: "kernel performance problem"
- Messages sorted by: [ date ] [ thread ] [ subject ] [ author ]
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