Re: elevator algorithm bug in ll_rw_blk.c

Tim Smith (tzs@tzs.net)
Sun, 15 Nov 1998 13:30:43 -0800 (PST)


> Normally you use a one-way scan. A two-way scan is unfair, it will
> service different parts of the disks diffrently. Specifically the
> edges will on average have a longer wait than the central parts.

It's not clear that there is anything wrong with being unfair. For
example, transfer rates on the outer part of the disk can be twice
what they are on the inner part, meaning it is unfair to put files
on the inner part of the disk, but no one seems to be losing much
sleep over that injustice. :-)

Heck, giving the central parts of the disk more frequent access might
be seen as making up for their slower transfer rate compared to the
outer edge. That only leaves the inner ghetto in poverty, as it is
both slow and has to wait longer...a perfect place to put your FAT
partition for Windows. :-)

--Tim Smith

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