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* GC some #if 0'd code.John Baldwin2001-09-211-8/+2
| | | | Notes: svn path=/head/; revision=83787
* Whitespace and spelling fixes.John Baldwin2001-09-211-2/+2
| | | | Notes: svn path=/head/; revision=83786
* KSE Milestone 2Julian Elischer2001-09-121-167/+220
| | | | | | | | | | | | | | | | | Note ALL MODULES MUST BE RECOMPILED make the kernel aware that there are smaller units of scheduling than the process. (but only allow one thread per process at this time). This is functionally equivalent to teh previousl -current except that there is a thread associated with each process. Sorry john! (your next MFC will be a doosie!) Reviewed by: peter@freebsd.org, dillon@freebsd.org X-MFC after: ha ha ha ha Notes: svn path=/head/; revision=83366
* Make yield() MPSAFE.Matthew Dillon2001-09-011-1/+6
| | | | | | | | | Synchronize syscalls.master with all MPSAFE changes to date. Synchronize new syscall generation follows because yield() will panic if it is out of sync with syscalls.master. Notes: svn path=/head/; revision=82711
* Release the sched_lock before bombing out in mi_switch() via db_error().John Baldwin2001-08-211-1/+3
| | | | | | | | This makes things slightly easier if you call a function that calls mi_switch() as it keeps the locking before and after closer. Notes: svn path=/head/; revision=82117
* Add a hook to mi_switch() to abort via db_error() if we attempt toJohn Baldwin2001-08-211-0/+12
| | | | | | | | | perform a context switch from DDB. Consulting from: bde Notes: svn path=/head/; revision=82096
* - Fix a bug in the previous workaround for the tsleep/endtsleep race.John Baldwin2001-08-211-2/+5
| | | | | | | | | | | | | | | | | | | callout_stop() would fail in two cases: 1) The timeout was currently executing, and 2) The timeout had already executed. We only needed to work around the race for 1). We caught some instances of 2) via the PS_TIMEOUT flag, however, if endtsleep() fired after the process had been woken up but before it had resumed execution, PS_TIMEOUT would not be set, but callout_stop() would fail, so we would block the process until endtsleep() resumed it. Except that endtsleep() had already run and couldn't resume it. This adds a new flag PS_TIMOFAIL to indicate the case of 2) when PS_TIMEOUT isn't set. - Implement this race fix for condition variables as well. Tested by: sos Notes: svn path=/head/; revision=82085
* - Close races with signals and other AST's being triggered while we are inJohn Baldwin2001-08-101-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | the process of exiting the kernel. The ast() function now loops as long as the PS_ASTPENDING or PS_NEEDRESCHED flags are set. It returns with preemption disabled so that any further AST's that arrive via an interrupt will be delayed until the low-level MD code returns to user mode. - Use u_int's to store the tick counts for profiling purposes so that we do not need sched_lock just to read p_sticks. This also closes a problem where the call to addupc_task() could screw up the arithmetic due to non-atomic reads of p_sticks. - Axe need_proftick(), aston(), astoff(), astpending(), need_resched(), clear_resched(), and resched_wanted() in favor of direct bit operations on p_sflag. - Fix up locking with sched_lock some. In addupc_intr(), use sched_lock to ensure pr_addr and pr_ticks are updated atomically with setting PS_OWEUPC. In ast() we clear pr_ticks atomically with clearing PS_OWEUPC. We also do not grab the lock just to test a flag. - Simplify the handling of Giant in ast() slightly. Reviewed by: bde (mostly) Notes: svn path=/head/; revision=81493
* Work around a race between msleep() and endtsleep() where it was possibleJohn Baldwin2001-08-101-3/+23
| | | | | | | | | | | | for endtsleep() to be executing when msleep() resumed, for endtsleep() to spin on sched_lock long enough for the other process to loop on msleep() and sleep again resulting in endtsleep() waking up the "wrong" msleep. Obtained from: BSD/OS Notes: svn path=/head/; revision=81482
* Style nit: covert a couple of if (p_wchan) tests to if (p_wchan != NULL).John Baldwin2001-08-101-3/+3
| | | | Notes: svn path=/head/; revision=81479
* - Remove asleep(), await(), and M_ASLEEP.John Baldwin2001-08-101-181/+1
| | | | | | | | | | | | - Callers of asleep() and await() have been converted to calling tsleep(). The only caller outside of M_ASLEEP was the ata driver, which called both asleep() and await() with spl-raised, so there was no need for the asleep() and await() pair. M_ASLEEP was unused. Reviewed by: jasone, peter Notes: svn path=/head/; revision=81397
* Use 'p' instead of the potentially more expensive 'curproc' inside ofJohn Baldwin2001-08-021-5/+5
| | | | | | | mi_switch(). Notes: svn path=/head/; revision=81072
* Apply the cluebat to myself and undo the await() -> mawait() rename. TheJohn Baldwin2001-07-311-31/+15
| | | | | | | | | | | | | | | | | | | | | | | asleep() and await() functions split the functionality of msleep() up into two halves. Only the asleep() half (which is what puts the process on the sleep queue) actually needs the lock usually passed to msleep() held to prevent lost wakeups. await() does not need the lock held, so the lock can be released prior to calling await() and does not need to be passed in to the await() function. Typical usage of these functions would be as follows: mtx_lock(&foo_mtx); ... do stuff ... asleep(&foo_cond, PRIxx, "foowt", hz); ... mtx_unlock&foo_mtx); ... await(-1, -1); Inspired by: dillon on the couch at Usenix Notes: svn path=/head/; revision=80766
* Add a safety belt to mawait() for the (cold || panicstr) case identical toJohn Baldwin2001-07-311-0/+12
| | | | | | | | | | the one in msleep() such that we return immediately rather than blocking. Submitted by: peter Prodded by: sheldonh Notes: svn path=/head/; revision=80761
* Backout mwakeup, etc.Jake Burkholder2001-07-061-13/+4
| | | | Notes: svn path=/head/; revision=79343
* Implement mwakeup, mwakeup_one, cv_signal_drop and cv_broadcast_drop.Jake Burkholder2001-07-041-4/+13
| | | | | | | | | | | | These take an additional mutex argument, which is dropped before any processes are made runnable. This can avoid contention on the mutex if the processes would immediately acquire it, and is done in such a way that wakeups will not be lost. Reviewed by: jhb Notes: svn path=/head/; revision=79172
* Remove commented-out garbage that skipped updating schedcpu() stats forJohn Baldwin2001-07-031-2/+0
| | | | | | | ithreads in SWAIT. Notes: svn path=/head/; revision=79132
* Just check p_oncpu when determining if a process is executing or not.John Baldwin2001-07-031-4/+1
| | | | | | | | | | We already did this in the SMP case, and it is now maintained in the UP case as well, and makes the code slightly more readable. Note that curproc is always executing, thus the p != curproc test does not need to be performed if the p_oncpu check is made. Notes: svn path=/head/; revision=79131
* Axe spl's that are covered by the sched_lock (and have been for quiteJohn Baldwin2001-07-031-30/+4
| | | | | | | some time.) Notes: svn path=/head/; revision=79130
* Include the wait message and channel for msleep() in the KTR tracepoint.John Baldwin2001-07-031-1/+2
| | | | Notes: svn path=/head/; revision=79128
* Remove bogus need_resched() of the current CPU in roundrobin().John Baldwin2001-07-031-3/+6
| | | | | | | | | | We don't actually need to force a context switch of the current process. The act of firing the event triggers a context switch to softclock() and then switching back out again which is equivalent to a preemption, thus no further work is needed on the local CPU. Notes: svn path=/head/; revision=79126
* Make the schedlock saved critical section state a per-thread property.John Baldwin2001-06-301-0/+3
| | | | Notes: svn path=/head/; revision=79003
* - Lock CURSIG() with the proc lock to close the signal race with psignal.John Baldwin2001-06-221-99/+67
| | | | | | | | | | | | | | | | | | | - Grab Giant around ktrace points. - Clean up KTR_PROC tracepoints to not display the value of sched_lock.mtx_lock as it isn't really needed anymore and just obfuscates the messages. - Add a few if conditions to replace gotos. - Ensure that every msleep KTR event ends up with a matching msleep resume KTR event (this was broken when we didn't do a mi_switch()). - Only note via ktrace that we resumed from a switch once rather than twice in several places in msleep(). - Remove spl's rom asleep and await as the proc lock and sched_lock provide all the needed locking. - In mawait() add in a needed ktrace point for noting that we are about to switch out. Notes: svn path=/head/; revision=78638
* Add in assertions to ensure that we always call msleep or mawait withJohn Baldwin2001-05-231-0/+4
| | | | | | | | | | either a timeout or a held mutex to detect unprotected infinite sleeps that can easily lead to deadlock. Submitted by: alfred Notes: svn path=/head/; revision=77059
* Remove KASSERT test for sleeping on mv_mtx, instead let WITNESS catchAlfred Perlstein2001-05-221-2/+0
| | | | | | | | | it. Requested by: jhb Notes: svn path=/head/; revision=76950
* remove my private assertions from tsleep.Alfred Perlstein2001-05-191-7/+2
| | | | | | | add one assertion to ensure we don't sleep while holding vm. Notes: svn path=/head/; revision=76830
* Introduce a global lock for the vm subsystem (vm_mtx).Alfred Perlstein2001-05-191-0/+7
| | | | | | | | | | | | | | | | | | | | | | vm_mtx does not recurse and is required for most low level vm operations. faults can not be taken without holding Giant. Memory subsystems can now call the base page allocators safely. Almost all atomic ops were removed as they are covered under the vm mutex. Alpha and ia64 now need to catch up to i386's trap handlers. FFS and NFS have been tested, other filesystems will need minor changes (grabbing the vm lock when twiddling page properties). Reviewed (partially) by: jake, jhb Notes: svn path=/head/; revision=76827
* - Remove unneeded include of sys/ipl.h.John Baldwin2001-05-151-1/+2
| | | | | | | | - Lock the process before calling killproc() to kill it for exceeding the maximum CPU limit. Notes: svn path=/head/; revision=76647
* Overhaul of the SMP code. Several portions of the SMP kernel support haveJohn Baldwin2001-04-271-5/+5
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | been made machine independent and various other adjustments have been made to support Alpha SMP. - It splits the per-process portions of hardclock() and statclock() off into hardclock_process() and statclock_process() respectively. hardclock() and statclock() call the *_process() functions for the current process so that UP systems will run as before. For SMP systems, it is simply necessary to ensure that all other processors execute the *_process() functions when the main clock functions are triggered on one CPU by an interrupt. For the alpha 4100, clock interrupts are delievered in a staggered broadcast fashion, so we simply call hardclock/statclock on the boot CPU and call the *_process() functions on the secondaries. For x86, we call statclock and hardclock as usual and then call forward_hardclock/statclock in the MD code to send an IPI to cause the AP's to execute forwared_hardclock/statclock which then call the *_process() functions. - forward_signal() and forward_roundrobin() have been reworked to be MI and to involve less hackery. Now the cpu doing the forward sets any flags, etc. and sends a very simple IPI_AST to the other cpu(s). AST IPIs now just basically return so that they can execute ast() and don't bother with setting the astpending or needresched flags themselves. This also removes the loop in forward_signal() as sched_lock closes the race condition that the loop worked around. - need_resched(), resched_wanted() and clear_resched() have been changed to take a process to act on rather than assuming curproc so that they can be used to implement forward_roundrobin() as described above. - Various other SMP variables have been moved to a MI subr_smp.c and a new header sys/smp.h declares MI SMP variables and API's. The IPI API's from machine/ipl.h have moved to machine/smp.h which is included by sys/smp.h. - The globaldata_register() and globaldata_find() functions as well as the SLIST of globaldata structures has become MI and moved into subr_smp.c. Also, the globaldata list is only available if SMP support is compiled in. Reviewed by: jake, peter Looked over by: eivind Notes: svn path=/head/; revision=76078
* Convert the allproc and proctree locks from lockmgr locks to sx locks.John Baldwin2001-03-281-6/+7
| | | | Notes: svn path=/head/; revision=74927
* Rework the witness code to work with sx locks as well as mutexes.John Baldwin2001-03-281-6/+6
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - Introduce lock classes and lock objects. Each lock class specifies a name and set of flags (or properties) shared by all locks of a given type. Currently there are three lock classes: spin mutexes, sleep mutexes, and sx locks. A lock object specifies properties of an additional lock along with a lock name and all of the extra stuff needed to make witness work with a given lock. This abstract lock stuff is defined in sys/lock.h. The lockmgr constants, types, and prototypes have been moved to sys/lockmgr.h. For temporary backwards compatability, sys/lock.h includes sys/lockmgr.h. - Replace proc->p_spinlocks with a per-CPU list, PCPU(spinlocks), of spin locks held. By making this per-cpu, we do not have to jump through magic hoops to deal with sched_lock changing ownership during context switches. - Replace proc->p_heldmtx, formerly a list of held sleep mutexes, with proc->p_sleeplocks, which is a list of held sleep locks including sleep mutexes and sx locks. - Add helper macros for logging lock events via the KTR_LOCK KTR logging level so that the log messages are consistent. - Add some new flags that can be passed to mtx_init(): - MTX_NOWITNESS - specifies that this lock should be ignored by witness. This is used for the mutex that blocks a sx lock for example. - MTX_QUIET - this is not new, but you can pass this to mtx_init() now and no events will be logged for this lock, so that one doesn't have to change all the individual mtx_lock/unlock() operations. - All lock objects maintain an initialized flag. Use this flag to export a mtx_initialized() macro that can be safely called from drivers. Also, we on longer walk the all_mtx list if MUTEX_DEBUG is defined as witness performs the corresponding checks using the initialized flag. - The lock order reversal messages have been improved to output slightly more accurate file and line numbers. Notes: svn path=/head/; revision=74912
* - Proc locking.John Baldwin2001-03-071-25/+7
| | | | | | | - Remove unneeded spl()'s. Notes: svn path=/head/; revision=73915
* Add a mtx_assert() in maybe_resched() just to be sure it's always calledJohn Baldwin2001-02-221-0/+1
| | | | | | | with sched_lock held. Notes: svn path=/head/; revision=72886
* - Use the new NOCPU constant.John Baldwin2001-02-221-2/+2
| | | | | | | | | - Fix a warning. Noticed by: bde (2) Notes: svn path=/head/; revision=72828
* - Don't call clear_resched() in userret(), instead, clear the resched flagJohn Baldwin2001-02-201-0/+8
| | | | | | | | | | | | | | | in mi_switch() just before calling cpu_switch() so that the first switch after a resched request will satisfy the request. - While I'm at it, move a few things into mi_switch() and out of cpu_switch(), specifically set the p_oncpu and p_lastcpu members of proc in mi_switch(), and handle the sched_lock state change across a context switch in mi_switch(). - Since cpu_switch() no longer handles the sched_lock state change, we have to setup an initial state for sched_lock in fork_exit() before we release it. Notes: svn path=/head/; revision=72746
* Implement a unified run queue and adjust priority levels accordingly.Jake Burkholder2001-02-121-58/+16
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | - All processes go into the same array of queues, with different scheduling classes using different portions of the array. This allows user processes to have their priorities propogated up into interrupt thread range if need be. - I chose 64 run queues as an arbitrary number that is greater than 32. We used to have 4 separate arrays of 32 queues each, so this may not be optimal. The new run queue code was written with this in mind; changing the number of run queues only requires changing constants in runq.h and adjusting the priority levels. - The new run queue code takes the run queue as a parameter. This is intended to be used to create per-cpu run queues. Implement wrappers for compatibility with the old interface which pass in the global run queue structure. - Group the priority level, user priority, native priority (before propogation) and the scheduling class into a struct priority. - Change any hard coded priority levels that I found to use symbolic constants (TTIPRI and TTOPRI). - Remove the curpriority global variable and use that of curproc. This was used to detect when a process' priority had lowered and it should yield. We now effectively yield on every interrupt. - Activate propogate_priority(). It should now have the desired effect without needing to also propogate the scheduling class. - Temporarily comment out the call to vm_page_zero_idle() in the idle loop. It interfered with propogate_priority() because the idle process needed to do a non-blocking acquire of Giant and then other processes would try to propogate their priority onto it. The idle process should not do anything except idle. vm_page_zero_idle() will return in the form of an idle priority kernel thread which is woken up at apprioriate times by the vm system. - Update struct kinfo_proc to the new priority interface. Deliberately change its size by adjusting the spare fields. It remained the same size, but the layout has changed, so userland processes that use it would parse the data incorrectly. The size constraint should really be changed to an arbitrary version number. Also add a debug.sizeof sysctl node for struct kinfo_proc. Notes: svn path=/head/; revision=72376
* Acquire sched_lock around need_resched() in roundrobin() to satisfyJake Burkholder2001-02-101-8/+4
| | | | | | | | assertions that it is held. Since roundrobin() is a timeout there's no possible way that it could be called with sched_lock held. Notes: svn path=/head/; revision=72330
* Change and clean the mutex lock interface.Bosko Milekic2001-02-091-42/+42
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | 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) Notes: svn path=/head/; revision=72200
* Zap last remaining references to (and a use use of) of simple_locks.Peter Wemm2001-01-311-4/+0
| | | | Notes: svn path=/head/; revision=71858
* - Catch up to proc flag changes.John Baldwin2001-01-241-25/+29
| | | | | | | | | - Add in some locking ops that might fix SIGXCPU, but don't enable them yet. - Assert that sched_lock is not recursed when mi_switch() is called. Notes: svn path=/head/; revision=71564
* Do not do the commenting out the way that saves bytes and looks cleanerMatt Jacob2001-01-231-1/+4
| | | | | | | to you. Do it the way Vox Populi wants it. Notes: svn path=/head/; revision=71436
* Move (now) unused variable declaration inside the block (now commented out).Matt Jacob2001-01-221-2/+1
| | | | Notes: svn path=/head/; revision=71391
* Temporarily disable the printf() for micruptime() going backwards, theJohn Baldwin2001-01-201-0/+5
| | | | | | | | | | SIGXCPU signal, and killing of processes that exceed their allowed run time until they can play nice with sched_lock. Right now they are just potentital panics waiting to happen. The printf() has bitten several people. Notes: svn path=/head/; revision=71288
* Implement condition variables.Jason Evans2001-01-161-6/+8
| | | | Notes: svn path=/head/; revision=71088
* Use PCPU_GET, PCPU_PTR and PCPU_SET to access all per-cpu variablesJake Burkholder2001-01-101-11/+12
| | | | | | | other then curproc. Notes: svn path=/head/; revision=70861
* - Change the allproc_lock to use a macro, ALLPROC_LOCK(how), insteadJake Burkholder2000-12-131-2/+2
| | | | | | | | | | | of explicit calls to lockmgr. Also provides macros for the flags pased to specify shared, exclusive or release which map to the lockmgr flags. This is so that the use of lockmgr can be easily replaced with optimized reader-writer locks. - Add some locking that I missed the first time. Notes: svn path=/head/; revision=69947
* Add in #include of <sys/lock.h> since it was axed from <sys/proc.h>.John Baldwin2000-12-061-0/+1
| | | | | | | | Noticed by: Wesley Morgan <morganw@chemikals.org> Pointy hat to: me Notes: svn path=/head/; revision=69645
* Remove thr_sleep and thr_wakeup. Remove fields p_nthread and p_wakeupJake Burkholder2000-12-021-0/+25
| | | | | | | | | | | | | from struct proc, which are now unused (p_nthread already was). Remove process flag P_KTHREADP which was untested and only set in vfs_aio.c (it should use kthread_create). Move the yield system call to kern_synch.c as kern_threads.c has been removed completely. moral support from: alfred, jhb Notes: svn path=/head/; revision=69512
* Use an mp-safe callout for endtsleep.Jake Burkholder2000-12-011-0/+2
| | | | Notes: svn path=/head/; revision=69437
* Fix up priority propagation:John Baldwin2000-11-301-1/+0
| | | | | | | | | | - Use a better test for determining when a process is running. - Convert some checks to assertions. - Remove unnecessary tests. - Save the priority before acquiring a mutex rather than in msleep(9). Notes: svn path=/head/; revision=69376
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