CVS commit: [netbsd-10] src/sys/kern

["Martin Husemann" <martin%netbsd.org@localhost>]

Module Name:    src
Committed By:   martin
Date:           Mon Jul 31 14:45:59 UTC 2023

Modified Files:
        src/sys/kern [netbsd-10]: kern_rwlock.c

Log Message:
Pull up following revision(s) (requested by riastradh in ticket #266):

        sys/kern/kern_rwlock.c: revision 1.68

rwlock(9): Fix membars.

rw_downgrade must be a release operation, and rw_tryupgrade must be
an acquire operation.  membar_producer is not enough -- need to use
membar_release and membar_acquire.

Discussed on tech-kern:
https://mail-index.netbsd.org/tech-kern/2023/02/22/msg028726.html


To generate a diff of this commit:
cvs rdiff -u -r1.66.4.1 -r1.66.4.2 src/sys/kern/kern_rwlock.c

Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.