Messages in this thread | | | Subject | Re: [PATCH] SMP race in ext2 - metadata corruption. | Date | Fri, 4 May 2001 13:40:54 +0200 (MEST) | From | (Rogier Wolff) |
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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 ** *-- BitWizard writes Linux device drivers for any device you may have! --* * There are old pilots, and there are bold pilots. * There are also old, bald pilots. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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