CVS commit: src/sys/arch

[Andrew Doran <ad%netbsd.org@localhost>]

Module Name:    src
Committed By:   ad
Date:           Tue May  6 22:57:39 UTC 2008

Modified Files:
        src/sys/arch/amd64/amd64: lock_stubs.S
        src/sys/arch/i386/i386: lock_stubs.S

Log Message:
rw_tryenter: there is a few instruction race between reading rw_owner and
doing the cmpxchg, where another thread can successfully get a read hold
on the lock. That shouldn't fail anyone trying trying to get a read
hold. So for read locks, never bail just because the CAS fails, only bail
if we the status bits in the lock word say we can't have it.


To generate a diff of this commit:
cvs rdiff -r1.16 -r1.17 src/sys/arch/amd64/amd64/lock_stubs.S
cvs rdiff -r1.17 -r1.18 src/sys/arch/i386/i386/lock_stubs.S

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