cvs commit: src/sys/conf NOTES files options src/sys/kern vfs_bio.c src/sys/ufs/ffs ffs_rawread.c ffs_vnops.c

Eivind Eklund eivind at
Thu Mar 27 03:16:05 PST 2003

On Wed, Mar 26, 2003 at 03:40:42PM -0800, Tor Egge wrote:
> tegge       2003/03/26 15:40:42 PST
>   FreeBSD src repository
>   Modified files:
>     sys/conf             NOTES files options 
>     sys/kern             vfs_bio.c 
>     sys/ufs/ffs          ffs_vnops.c 
>   Added files:
>     sys/ufs/ffs          ffs_rawread.c 
>   Log:
>   Add support for reading directly from file to userland buffer when the
>   O_DIRECT descriptor status flag is set and both offset and length is a
>   multiple of the physical media sector size.

Why only in the O_DIRECT case?  O_DIRECT is normally used to avoid caching
effects *in order to avoid side effects of caching*, at the cost of speed.
This patch seems to do the opposite - speed up the codepath significantly.

Not that it isn't nice - it would just be even nicer to have available some
way to just say "max speed, please".


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