* scheduler_enqueue_in_runqueue() now allows the scheduler to return a hint as to whether a reschedule is desirable or not. This is used in a few other places in order to relegate scheduling decisions entirely to the scheduler rather than the priority hacks previously used. There are probably other places in the kernel that could now make use of that information to more intelligently call reschedule() though.
* Switch over the default scheduler to scheduler_affine().
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- Moved scheduler listening interface to <listeners.h> and added more
convenient to use templatized notification functions.
- Added a listener mechanism for the wait objects (semaphores, condition
variables, mutex, rw_lock).
* system profiler:
- Hopefully fixed locking issues related to notifying the profiler thread
for good. We still had an inconsistent locking order, since the scheduler
notification callbacks are invoked with the thread lock held and have to
acquire the object lock then, while the other callbacks acquired the object
lock first and as a side effect of ConditionVariable::NotifyOne() acquired
the thread lock. Now we make sure the object lock is the innermost lock.
- Track the number of dropped events due to a full buffer.
_user_system_profiler_next_buffer() returns this count now.
- When scheduling profiling events are requested also listen to wait objects
and generate the respective profiling events. We send those events lazily
and cache the infos to avoid resending an event for the same wait object.
- When starting profiling we do now generate "thread scheduled" events for
the already running threads.
- _user_system_profiler_start(): Check whether the parameters pointer is a
userland address at all.
- The system_profiler_team_added event does now also contain the team's name.
* Added a sem_get_name_unsafe() returning a semaphore's name. It is "unsafe",
since the caller has to ensure that the semaphore exists and continues to
exist as long as the returned name is used.
* Adjusted the "profile" and "scheduling_recorder" according to the system
profiling changes. The latter prints the number of dropped events, now.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@30345 a95241bf-73f2-0310-859d-f6bbb57e9c96
are still allowed to delete semaphores of other teams...
* Anyway, this fixes bug #3585.
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* Turned the checks for all those macros to "#if"s instead of "#ifdef"s.
* Introduced macro KDEBUG_LEVEL which serves as a master setting.
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than that of the current thread has been woken up. I didn't see the
reason why the thread should otherwise relinquish the rest of its
quantum. I noticed for instance that client and app server window
threads were ping-ponging more than seemed necessary. In most cases
when the client sent a port message it would be unscheduled although it
had run only for a few microseconds and had still stuff to do.
I measured a relatively Terminal-heavy "find /boot" (second run), which
does now take 5-10% less time.
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unscheduled was incorrect.
* Introduced _kern_analyze_scheduling() syscall. It requires scheduler
kernel tracing to be enabled. It uses the tracing entries for a given
period of time to do a similar analysis the "scheduler" debugger
command does (i.e. number of runs, run time, latencies, preemption
times) for each thread. Additionally the analysis includes for each
thread how long the thread waited on each locking primitive in total.
* Added kernel tracing for the creation of semaphores and initialization
of condition variables, mutexes, and rw locks. The enabling macro is
SCHEDULING_ANALYSIS_TRACING. The only purpose is to provide
_kern_analyze_scheduling() with more info on the locking primitives
(the name in particular).
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gTeamSpinlock.
* Renamed the static global variables in smp.c to match our style guide.
* Minor other cleanup.
* Removed superfluous white space.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26730 a95241bf-73f2-0310-859d-f6bbb57e9c96
introduces the following relevant changes:
* VMCache:
- Renamed vm_cache to VMCache, merged it with vm_store and made it a
C++ class with virtual methods (replacing the store operations).
Turned the different store implementations into subclasses.
- Introduced MergeStore() callback, changed semantics of Commit().
- Changed locking and referencing semantics. A reference can only be
acquired/released with the cache locked. An unreferenced cache is
deleted and a mergeable cache merged when it is unlocked. This
removes the "busy" state of a cache and simplifies the page fault
code.
* Added VMAnonymousCache, which will implement swap support (work by
Zhao Shuai). It is not integrated and used yet, though.
* Enabled the mutex/recursive lock holder asserts.
* Fixed DoublyLinkedList::Swap().
* Generalized the low memory handler to a low resource handler. And made
semaphores and reserved memory handled resources. Made
vm_try_resource_memory() optionally wait (with timeout), and used that
feature to reserve memory for areas.
...
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@26572 a95241bf-73f2-0310-859d-f6bbb57e9c96
B_DEBUG_SPINLOCK_CONTENTION is defined to 1. It typedefs spinlock to a
structure (thus breaking BeOS binary compatibility), containing a
counter which is incremented whenever a thread has to wait for the
spinlock.
* Added macros for spinlock initialization and access and changed
code using spinlocks accordingly. This breaks compilation for BeOS --
the macros should be defined in the respective compatibility wrappers.
* Added generic syscall to get the spinlock counters for the thread and
the team spinlocks.
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Realtime option group). The implementation should be complete, but is
totally untested yet.
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cleverness to reschedule only, if it actually unblocked another thread.
Should have been the reason for #2152 (overall slowdown).
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thread_block(), thread_unblock(),...) that allow a thread to wait for
something without needing a semaphore or condition variable. It can
simply block and another thread can unblock it. Supports timeouts and
interrupting. Both semaphores and condition variables use this
common mechanism, now.
* Semaphores:
- Some simplifications due to the thread blocking mechanism.
- Changed locking order to sem -> thread. It was the other way around
before and when introducing the wait_for_objects() support I had
also introduced a situation where the locking was reverse, which
could potentially cause a dead lock on SMP systems.
- Instead of queueing thread structures, a semaphore queues
queued_thread entries now, which are created on the stack. The
thread::sem structure could thus be removed.
- Added sem_entry::net_count, which is sem_entry::count plus the
acquisition count of all waiting threads. This number is needed in
remove_thread_from_sem() and instead of computing it there we
maintain it.
- Fixed remove_thread_from_sem(). It would not unblock threads, if
the sem count was <= 0.
- Made sem::last_acquirer unconditional. It is actually needed for
sem_info::latest_holder. Fixed fill_sem_info() accordingly.
- Added some optional tracing output, though only via ktrace_printf().
* Condition variables:
- Could be simplified significantly through the use of the thread
blocking mechanism. Removed a good deal of unnecessary code.
- Moved the ConditionVariableEntry "flags" parameter from Wait() to
Add(), and adjusted all places where condition variables are used
accordingly.
* snooze() uses thread_block_with_timeout() instead of a semaphore.
* Simplified thread interrupting in the signal and user debugger code.
Instead of separate functions for threads waiting on a semaphore or
condititon variable, we only have a single thread_interrupt(), now.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@25099 a95241bf-73f2-0310-859d-f6bbb57e9c96
API, uses the _PRINTFLIKE macro where appropriate.
* Got rid of the "qent" structure, struct timer now contains everything we
need. This makes the affected code in sem.cpp, signal.cpp, and timer.c much
cleaner, and resolves a few TODOs.
* Minor cleanup in vfs.cpp.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24871 a95241bf-73f2-0310-859d-f6bbb57e9c96
need to make sure that we never get that far with a negative timeout or
we'll wait forever.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@24083 a95241bf-73f2-0310-859d-f6bbb57e9c96
* Implemented automatic syscall restarts:
- A syscall can indicate that it has been interrupted and can be
restarted by setting a respective bit in thread::flags. It can
store parameters it wants to be preserved for the restart in
thread::syscall_restart::parameters. Another thread::flags bit
indicates whether it has been restarted.
- handle_signals() clears the restart flag, if the handled signal
has a handler function installed and SA_RESTART is not set. Another
thread flag (THREAD_FLAGS_DONT_RESTART_SYSCALL) can prevent syscalls
from being restarted, even if they could be (not used yet, but we
might want to use it in resume_thread(), so that we stay
behaviorally compatible with BeOS).
- The architecture specific syscall handler restarts the syscall, if
the restart flag is set. Implemented for x86 only.
- Added some support functions in the private <syscall_restart.h> to
simplify the syscall restart code in the syscalls.
- Adjusted all syscalls that can potentially be restarted accordingly.
- _user_ioctl() sets new thread flag THREAD_FLAGS_IOCTL_SYSCALL while
calling the underlying FS's/driver's hook, so that syscall restarts
can also be supported there.
* thread_at_kernel_exit() invokes handle_signals() in a loop now, as
long as the latter indicates that the thread shall be suspended, so
that after waking up signals received in the meantime will be handled
before the thread returns to userland. Adjusted handle_signals()
accordingly -- when encountering a suspending signal we don't check
for further signals.
* Fixed sigsuspend(): Suspending the thread and rescheduling doesn't
result in the correct behavior. Instead we employ a temporary
condition variable and interruptably wait on it. The POSIX test
suite test passes, now.
* Made the switch_sem[_etc]() behavior on interruption consistent.
Depending on when the signal arrived (before the call or when already
waiting) the first semaphore would or wouldn't be released. Now we
consistently release it.
* Refactored _user_{read,write}[v]() syscalls. Use a common function for
either pair. The iovec version doesn't fail anymore, if anything could
be read/written at all. It also checks whether a complete vector
could be read/written, so that we won't skip data, if the underlying
FS/driver couldn't read/write more ATM.
* Some refactoring in the x86 syscall handler: The int 99 and sysenter
handlers use a common subroutine to avoid code duplication.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23983 a95241bf-73f2-0310-859d-f6bbb57e9c96
systems it can easily happen that the thread gets removed from the queue (when
it times out for example) during the time we don't hold the sem lock.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23749 a95241bf-73f2-0310-859d-f6bbb57e9c96
at the end of that loop we guaranteed a crash when this special handling was
triggered.
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This should be in line with all uses of scheduler_enqueue_in_run_queue() and
simplifies a few places where it is used.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23738 a95241bf-73f2-0310-859d-f6bbb57e9c96
enqueued into the run_queue again. Modified the workaround to a panic in the
scheduler so we notice when something else does the same.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@23731 a95241bf-73f2-0310-859d-f6bbb57e9c96
