Re: [PATCH] 64 bit scsi read/write

From: Chris Wedgwood (cw@f00f.org)
Date: Sun Jul 15 2001 - 11:24:26 EST

On Sun, Jul 15, 2001 at 04:32:59PM +0100, Alan Cox wrote:

    Another way is to time

            write block
            write barrier
            write same block
            write barrier
            repeat

    If the write barrier is working you should be able to measure the
    drive rpm 8)

OK, I just wrote this in order to test just that, test on a raw device
and turn caching off if you can.

For my drives, I cannot disable caching (I don't know if it is on or
not) and I get abysmal speed, but nothing unrealistic,

Anyhow, I just wrote this and tested it a couple of times, if it
breaks or east your disk, don't bitch at me.

Otherwise, flames and comments on my god awful code welcome.

  --cw


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