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

[John Baldwin]

On Friday 06 January 2006 01:07 pm, John Baldwin wrote:
> jhb         2006-01-06 18:07:32 UTC
>
>   FreeBSD src repository
>
>   Modified files:
>     sys/kern             kern_mutex.c kern_sx.c subr_witness.c
>     sys/sys              _lock.h lock.h
>   Log:
>   Trim another pointer from struct lock_object (and thus from struct mtx
> and struct sx).  Instead of storing a direct pointer to a our lock_class
> struct in lock_object, reserve 4 bits in the lo_flags field to serve as an
> index into a global lock_classes array that contains pointers to the lock
> classes.  Only debugging code such as WITNESS or INVARIANTS checks and KTR
> logging need to access the lock_class member, so this shouldn't add any
> overhead to production kernels.  It might add some slight overhead to
> kernels using those debug options however.
>
>   As with the previous set of changes to lock_object, this is going to
>   completely obliterate the kernel ABI, so be sure to recompile all your
>   modules.

Forgot:

Tested on:	alpha, amd64, i386, sparc64

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