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SubjectRe: [PATCH] SMP race in ext2 - metadata corruption.
Date
From
Linus Torvalds wrote:
>
> On Thu, 3 May 2001, Alan Cox wrote:
> > Ditto for some CD based stuff. You burn the important binaries to the front
> > of the CD, then at boot dd 64Mb to /dev/null to prime the libraries and
> > avoid a lot of seeking during boot up from the CD-ROM.
> >
> > However I could do that from an initrd before mounting
>
> Ehh. Doing that would be extremely stupid, and would slow down your boot
> and nothing more.

Ehhh, Linus, Linearly reading my harddisk goes at 26Mb per second. By
analyzing my boot process I determine that 50M of my disk is used
during boot. I can then reshuffle my disk to have that 50M of data at
the beginning and reading all that into 50M of cache, I can save
thousands of 10ms seeks. Boot time would go from several tens of
seconds to 2 seconds worth of DISK IO plus several seconds of pure CPU
time.

This doesn't work if I don't have the memory to cache 50M of
disk-blocks.

Is this simply: Don't try this then?

Roger.


--
** R.E.Wolff@BitWizard.nl ** http://www.BitWizard.nl/ ** +31-15-2137555 **
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* There are also old, bald pilots.
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