OpenBSD cvs log

created 2019-03-16T15:58:37Z
begin 2019-03-09T00:00:00Z
end 2019-03-10T00:00:00Z
path src/sys
commits 3

date 2019-03-09T06:14:21Z
author visa
files src/sys/sys/atomic.h log diff annotate
message Add macros READ_ONCE() and WRITE_ONCE(). They constrain optimizations
done by the compiler.

OK guenther@

date 2019-03-09T06:15:48Z
author visa
files src/sys/sys/smr.h log diff annotate
message Use READ_ONCE() and WRITE_ONCE() in .

OK guenther@

date 2019-03-09T23:04:56Z
author cheloha
files src/sys/kern/kern_tc.c log diff annotate
message tc_windup: read active timecounter once at function start.

tc_windup() is not necessarily called with KERNEL_LOCK, so it is possible
for the timecounter pointer to change in the midst of the call via the
kern.timecounter.hardware sysctl(2). Reading it once and using that local
copy ensures we're referring to the same timecounter consistently.

Apparently the compiler can optimize this out... somehow... so there may
be room for improvement.

Idea from visa@. With input from visa@, mpi@, cjeker@, and guenther@.

ok visa@ mpi@