mtx_enter(lock, type) becomes:
mtx_lock(lock) for sleep locks (MTX_DEF-initialized locks)
mtx_lock_spin(lock) for spin locks (MTX_SPIN-initialized)
similarily, for releasing a lock, we now have:
mtx_unlock(lock) for MTX_DEF and mtx_unlock_spin(lock) for MTX_SPIN.
We change the caller interface for the two different types of locks
because the semantics are entirely different for each case, and this
makes it explicitly clear and, at the same time, it rids us of the
extra `type' argument.
The enter->lock and exit->unlock change has been made with the idea
that we're "locking data" and not "entering locked code" in mind.
Further, remove all additional "flags" previously passed to the
lock acquire/release routines with the exception of two:
MTX_QUIET and MTX_NOSWITCH
The functionality of these flags is preserved and they can be passed
to the lock/unlock routines by calling the corresponding wrappers:
mtx_{lock, unlock}_flags(lock, flag(s)) and
mtx_{lock, unlock}_spin_flags(lock, flag(s)) for MTX_DEF and MTX_SPIN
locks, respectively.
Re-inline some lock acq/rel code; in the sleep lock case, we only
inline the _obtain_lock()s in order to ensure that the inlined code
fits into a cache line. In the spin lock case, we inline recursion and
actually only perform a function call if we need to spin. This change
has been made with the idea that we generally tend to avoid spin locks
and that also the spin locks that we do have and are heavily used
(i.e. sched_lock) do recurse, and therefore in an effort to reduce
function call overhead for some architectures (such as alpha), we
inline recursion for this case.
Create a new malloc type for the witness code and retire from using
the M_DEV type. The new type is called M_WITNESS and is only declared
if WITNESS is enabled.
Begin cleaning up some machdep/mutex.h code - specifically updated the
"optimized" inlined code in alpha/mutex.h and wrote MTX_LOCK_SPIN
and MTX_UNLOCK_SPIN asm macros for the i386/mutex.h as we presently
need those.
Finally, caught up to the interface changes in all sys code.
Contributors: jake, jhb, jasone (in no particular order)
Generate a version string that looks just like a real Linux one - almost :)
Use sbufs everywhere instead of sprintf(). Note that this is still imperfect,
as the code does not check whether the sbuf overflowed - but it'll still
work better than before, since if the sbuf overflows, the code now simply
copies out 0 bytes instead of causing a trap (or worse, corrupting kernel
structures)
waiting for procfs to get fixed:
- Use fill_eproc() to obtain correct VM stats. Attempt to compute VmLib.
- Fill some more fields in proc/<pid>/stat, and add four (unimplemented)
fields after studying a recent Linux kernel.
- Compute CPU frequency only once instead of twice.
- Fix some comments that were OBE.
- Fix indentation except where it makes the code less readable.
the build (oops!): replace calls to p_trespass() and PRISON_CHECK()
with p_can(..., {P_CAN_SEE, P_CAN_DEBUG}, NULL)
o Remove volatile usage from procfs_readdir() to remove warnings
o Apply bp's CREATE fix to linprocfs, causing EROFS to be returned on
CREATE calls to procfs_lookup()
o Some further synchronization still needs to occur: only existing
access checks were replaced, to fix the build--the new ones were not
added. I'll do this later today, this is a "fix the build quickly"
commit. This means that, in the interim, some information leakage
can still occur via linprocfs when using jail or kern.ps_showallprocs
Submitted by: knu
Approved by: des
Obtained from: TrustedBSD Project
