cvs commit: src/sys/kern subr_witness.c src/sys/sys _lock.h lock.h

[John Baldwin]

On Monday 05 December 2005 03:45 pm, John Baldwin wrote:
> jhb         2005-12-05 20:45:24 UTC
>
>   FreeBSD src repository
>
>   Modified files:
>     sys/kern             subr_witness.c
>     sys/sys              _lock.h lock.h
>   Log:
>   Tweak witness handling of lock object to shave 2 pointers off of each
>   lock object (and thus off of each mutex and sx lock):
>
>   ...
>
>   With these changes, struct mtx shrinks from 36 to 28 bytes on 32-bit
>   platforms and from 72 to 56 bytes on 64-bit platforms.  Note that this
>   commit will completely and utterly destroy the kernel ABI, so no MFC.
>
>   Tested on:      alpha, amd64, i386, sparc64

andre@ reported a 5% perf increase from this change on at least one network 
benchmark.

-- 
John Baldwin <jhb at FreeBSD.org>  <><  http://www.FreeBSD.org/~jhb/
"Power Users Use the Power to Serve"  =  http://www.FreeBSD.org