Re: Checksum on Alpha

Richard Henderson (rth@twiddle.net)
Mon, 21 Jun 1999 23:17:48 -0700


On Wed, Jun 02, 1999 at 02:18:22AM -0400, Bharadwaj Yadavalli wrote:
> Can somebody kindly explain me why the implementation of
> csum_partial_copy_from_user() returns a 16-bit checksum ...

Because there is no checksum_t type, lots of places throughout the
kernel store partial checksums in an `int'. So we can't return the
64-bit partial sum like we'd like, so we do several folds to fit in
32 bits.

We actually return a 17-bit sum -- a fully folded result would
have to go one more round.

r~

-
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/