Re: [PATCH] SMP race in ext2 - metadata corruption.

[R.E.Wolff@BitWizard.nl (Rogier Wolff)]

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. 


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