cvs commit: src/sys/kern subr_witness.c src/sys/sys _lock.h lock.h
jhb at FreeBSD.org
Mon Dec 5 12:45:45 PST 2005
jhb 2005-12-05 20:45:24 UTC
FreeBSD src repository
sys/sys _lock.h lock.h
Tweak witness handling of lock object to shave 2 pointers off of each
lock object (and thus off of each mutex and sx lock):
- Rename the all_locks list to pending_locks and only put locks initialized
before SI_SUB_WITNESS on the list so that the SI_SUB_WITNESS can add them
to witness once it starts up.
- Now that pending_locks is only used during early startup, change it from
a TAILQ to an STAILQ. This removes a pointer from the STAILQ_ENTRY in
- Since the pending_locks list is only used during the single-threaded
early boot it no longer needs to be protected by a mutex, so remove
- Since the lo_list member of struct lock_object is now only used during
early boot before witness is running, collapse lo_list and lo_witness
into a union. This shaves the second pointer off of struct lock_object.
- Axe lock_cur_cnt and lock_max_cnt.
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
Revision Changes Path
1.207 +44 -44 src/sys/kern/subr_witness.c
1.11 +4 -2 src/sys/sys/_lock.h
1.53 +1 -0 src/sys/sys/lock.h
More information about the cvs-src