Quake II needs a lot of stack, it was overflowing my 256 KiB stack so
this patch doubles that, so Quake II can run!
Also every thread had 256 KiB kernel stack. This is unnecessarily large
and now dropped to 32 KiB.
SSE is now unconditionally enabled any where and most of math.h is now
actually implemented. using __builtin_<func> lead to many hangs where
the builtin function would just call itself.
This patch builds new executable image to another pml4 structure and
only after everything is validated will current context be replaced.
This allows exec to fail "late" where previously it would panic the
kernel or kill the process. This allows graceful handling of exec
failures in userspace!
Change Semaphore -> ThreadBlocker
This was not a semaphore, I just named it one because I didn't know
what semaphore was. I have meant to change this sooner, but it was in
no way urgent :D
Implement SMP events. Processors can now be sent SMP events through
IPIs. SMP events can be sent either to a single processor or broadcasted
to every processor.
PageTable::{map_page,map_range,unmap_page,unmap_range}() now send SMP
event to invalidate TLB caches for the changed pages.
Scheduler no longer uses a global run queue. Each processor has its own
scheduler that keeps track of the load on the processor. Once every
second schedulers do load balancing. Schedulers have no access to other
processors' schedulers, they just see approximate loads. If scheduler
decides that it has too much load, it will send a thread to another
processor through a SMP event.
Schedulers are currently run using the timer interrupt on BSB. This
should be not the case, and each processor should use its LAPIC timer
for interrupts. There is no reason to broadcast SMP event to all
processors when BSB gets timer interrupt.
Old scheduler only achieved 20% idle load on qemu. That was probably a
very inefficient implementation. This new scheduler seems to average
around 1% idle load. This is much closer to what I would expect. On my
own laptop idle load seems to be only around 0.5% on each processor.
This was broken when I added SMP support. This patch makes sse kind of
dumb as it is saved and restored on every interrupt, but now it at least
works properly... I'll have to look into how sse can get optimized
nicely with SMP. Simple way would be pinning each thread to a specific
processor and doing pretty much what I had before, but sse thread saved
in processor rather than static global.
This implements only parsing for AML in qemu. InvokeMethods are not
parsed since number of arguments to Methods is not yet known.
Parsing AML uses multiple kilobytes of stack space, so I increased
boot stack size by a lot :D
I am not sure where my own AML is going, but this is good start if
I decide to implement full ACPI on my own.
This code is very much just ugly macro expansion.
Qemu has 2 DefPackage elements that I am not able to parse. Package
data ends while there should be still multiple elements.
Current context saving was very hacky and dependant on compiler
behaviour that was not consistent. Now we always use iret for
context saving. This makes everything more clean.
Signal handling code was way too complex. Now everything is
simplified and there is no need for ThreadBlockers.
Only complication that this patch includes is that blocking syscalls
have to manually be made interruptable by signal. There might be some
clever solution to combat this is make this happen automatically.
When we want to kill a process, we mark its threads as Terminating
or Terminated. If the thread is in critical section that has to be
finished, it will be in Terminating state until done. Once Scheduler
is trying to execute Terminated thread it will instead delete it.
Once processes last thread is marked Terminated, the processes will
turn it into a cleanup thread, that will allow blocks and memory
cleanup to be done.
I added a syscall for telling the kernel when signal execution has
finished. We should send a random hash or id to the signal trampoline
that we would include in the syscall, so validity of signal exit can
be confirmed.
Bananymous
Bananymous