critical_enter() and critical_exit() are now solely a mechanism for
deferring kernel preemptions. They no longer have any affect on
interrupts. This means that standalone critical sections are now very
cheap as they are simply unlocked integer increments and decrements for the
common case.
Spin mutexes now use a separate KPI implemented in MD code: spinlock_enter()
and spinlock_exit(). This KPI is responsible for providing whatever MD
guarantees are needed to ensure that a thread holding a spin lock won't
be preempted by any other code that will try to lock the same lock. For
now all archs continue to block interrupts in a "spinlock section" as they
did formerly in all critical sections. Note that I've also taken this
opportunity to push a few things into MD code rather than MI. For example,
critical_fork_exit() no longer exists. Instead, MD code ensures that new
threads have the correct state when they are created. Also, we no longer
try to fixup the idlethreads for APs in MI code. Instead, each arch sets
the initial curthread and adjusts the state of the idle thread it borrows
in order to perform the initial context switch.
This change is largely a big NOP, but the cleaner separation it provides
will allow for more efficient alternative locking schemes in other parts
of the kernel (bare critical sections rather than per-CPU spin mutexes
for per-CPU data for example).
Reviewed by: grehan, cognet, arch@, others
Tested on: i386, alpha, sparc64, powerpc, arm, possibly more
specific code will migrate to these files to augment or replace the
version in i386/include and/or i386/linux. This should, in the
fullness of time, allow many of the #ifdef PC98 in the tree.
# These files are in the public domain because there is insufficient
# creative content in them. When you customize them, please add a
# copyright notice and license.
OK'd in principle by: nyan@
FreeBSD based on aue(4) it was picked by OpenBSD, then from OpenBSD ported
to NetBSD and finally NetBSD version merged with original one goes into
FreeBSD.
Obtained from: http://www.gank.org/freebsd/cdce/
NetBSD
OpenBSD
This is mentioned in the Handbook but it is not as obvious to new
users why bpf is needed compared to the other largely self-explanatory
items in GENERIC.
PR: conf/40855
MFC after: 1 week
turns out that LINE30_ROW was always defined, not LINE30. I confused
this for LINE30 and did the unifdef -DLINE30 using that mistaken
belief. This corrects that problem.
Submitted by: nyan-san
copyright/license header and was only used by 30line.h. It appears
that the copyright/license in 30line.h covers the old contents
module.h anyway, so this simplifies things a little while cleaning up
one obscure potential license confusion...
Revired by: nyan-san
from 4.x kernel config files. User's wishing to upgrade from 4.x to 6
will need to go through 5.x, or grab this script from there. These
scripts will remain in RELENG_5...
