not work; it would always choose the last thread of the current priority.
IOW a thread was never skipped, and lower priority threads were never called
when a higher priority thread was running - from the POV of the scheduler,
we only has real time threads...
* Improved "run_queue" KDL output.
* Minor cleanup.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@22515 a95241bf-73f2-0310-859d-f6bbb57e9c96
threads with higher priorities a much better scheduling experience, it
also creates a problem as soon as more than one higher priority thread
waits on a resource held by a lower priority thread; the higher priority
threads play ping-pong, and the lower priority thread doesn't get it's
chance.
* Increased the probability of skipping a thread priority.
* I won't do any other changes on the scheduler, that's meianote's job now :-)
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@20758 a95241bf-73f2-0310-859d-f6bbb57e9c96
yet sure what is causing this, but until I find the time to look into it (or someone else
as part of GSoC), raising the limit helps.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@20427 a95241bf-73f2-0310-859d-f6bbb57e9c96
for one quantum wasn't really a good idea, as this could get quite expensive for the thread
(depending on the system load, it might have taken a long time until the thread was scheduled
again, no matter what priority it was).
Also, calling thread_yield() in a loop would have taken 100% CPU time.
Now, we sort the thread into the queue as with any other thread, but we'll ignore it once.
This now guarantees an actual context switch, as well as a much fairer rescheduling policy
for threads calling that function.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@20077 a95241bf-73f2-0310-859d-f6bbb57e9c96
with a lower priority than the current one.
* Further reduced the probability to skip a thread to roughly 4%, that makes around
13 skips per second, and about 40 msecs spend in lower priority threads per second
(with a 3 msec quantum). Might still be too much, but we'll see.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@19719 a95241bf-73f2-0310-859d-f6bbb57e9c96
not a penalty to be the first thread in the run queue...
I've reduced it to about 12.5%, but that might still be too much.
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@19710 a95241bf-73f2-0310-859d-f6bbb57e9c96
time of the idle thread as a measure, we now compute the CPU activity on
each thread switch - the time the CPU worked is the total of user and kernel
time a thread spent during its quantum.
Unlike before, this mechanism works correctly on SMP machines. I hope this
works as expected :)
git-svn-id: file:///srv/svn/repos/haiku/haiku/trunk@16193 a95241bf-73f2-0310-859d-f6bbb57e9c96
Axel Dörfler