Commit graph

485 commits

Author SHA1 Message Date
Tomas Hruby
4f962b4798 A small mini_receive() cleanup
- this patch substitutes *xpp for sender to increase readability of
  mini_receive().

- makes sure that the dequeued sender has p_q_link == NULL and that
  this condition holds when enqueuing the sender again. 

- it is a sanity check to make sure that the new sender is not
  enqueued already. Before this change the dequeued sender's p_q_link
  may not be NULL and it was only set to NULL when enqueued again.
2010-05-07 11:22:49 +00:00
Ben Gras
b8eddf00d8 kernel: don't try to lookup ANY in debug output. 2010-05-06 22:39:11 +00:00
Ben Gras
0194fe55dc kernel: increase some per-process privilege limits. 2010-05-06 22:21:08 +00:00
Tomas Hruby
ec56479675 deadlock() - more info
- deadlock() is more verbose in case of a detected deadlock. First, it
  lists all processses in the deadlock group. Then it prints the proc
  extra info, not only  stack trace and register dump
2010-05-03 17:38:54 +00:00
Tomas Hruby
57a88ce708 debugging - printing processes on serial
- this patch moves the former printslot() from arch_system.c to
  debug.c and reimplements it slightly. The output is not changed,
  however, the process information is printed in a separate function
  print_proc() in debug.c as such a function is also handy in other
  situations and should be publicly available when debugging.
2010-05-03 17:37:18 +00:00
Ben Gras
4e837dcfb3 kernel: more diagnostics for privctl ENOMEM conditions. 2010-04-29 08:50:52 +00:00
Ben Gras
50335291ae kernel: fpu_init: only enable OSXMMEXCPT in CR4 on at least SSE1 machines.
Found and debugged by totalinux at yandex.ru and Evgeniy Ivanov, thanks!
2010-04-28 13:51:02 +00:00
Ben Gras
c37401f23f kernel: fpu init to separate function; also move fpu init down
moving the fpu code causes exceptions raised by it to be trapped
neatly instead of causing a triple fault, before the IDT is initialized.
2010-04-28 13:25:29 +00:00
Erik van der Kouwe
84d404aba3 Fix types in debug register functions 2010-04-28 08:35:05 +00:00
Tomas Hruby
b528d52ea8 pagefault() is private 2010-04-27 20:30:33 +00:00
Erik van der Kouwe
4bddc57477 Remove debug printfs in breakpoints.c, they should never have been there 2010-04-27 12:25:04 +00:00
Tomas Hruby
f51eea4b32 Changed pagefault delivery to VM
this patch changes the way pagefaults are delivered to VM. It adopts
the same model as the out-of-quantum messages sent by kernel to a
scheduler.

- everytime a userspace pagefault occurs, kernel creates a message
  which is sent to VM on behalf of the faulting process

- the process is blocked on delivery to VM in the standard IPC code
  instead of waiting in a spacial in-kernel queue (stack) and is not
  runnable until VM tell kernel that the pagefault is resolved and is
  free to clear the RTS_PAGEFAULT flag.

- VM does not need call kernel and poll the pagefault information
  which saves many (1/2?) calls and kernel calls that return "no more
  data"

- VM notification by kernel does not need to use signals

- each entry in proc table is by 12 bytes smaller (~3k save)
2010-04-26 23:21:26 +00:00
Ben Gras
86e8eff905 remove intr_disabled() as interrupts are always disabled in the kernel now. 2010-04-26 15:32:42 +00:00
Cristiano Giuffrida
0f353411d7 Set IPC status code only for RECEIVE 2010-04-26 14:43:59 +00:00
Kees van Reeuwijk
d106968d77 Remove useless symbol declarations from headers, make symbols local where possible, add some explicit initialization to global variables. 2010-04-22 07:49:40 +00:00
Kees van Reeuwijk
86a23c1fbd Remove U16_t and most other similar types. Rewrite functions to ansi-style
declaration if necessary.
2010-04-21 11:05:22 +00:00
Kees van Reeuwijk
b412fb7ad5 Code cleanup: remove unused #include, variables and code, 2010-04-15 18:49:36 +00:00
Erik van der Kouwe
8b459cfbb3 Provide information on lethal signals (stacktrace and signo) 2010-04-14 09:06:34 +00:00
Kees van Reeuwijk
fa3adedf63 Remove some duplicate declarations in headers.
Explicitly declare some functions as returning void.
2010-04-13 15:22:38 +00:00
Kees van Reeuwijk
bc314bda91 Remove the types Dev_t, _mnx_Gui, _mnx_Uid, and similar.
Use ANSI-style function declarations where necessary.
2010-04-13 10:58:41 +00:00
Tomas Hruby
9b599bac1d Quantum in fork
- This patch removes the time slice split between parent and child in
  fork.

- The time slice of the parent remains unchanged and the child does
  not have any.

- If the process has a scheduler, the scheduler must assign the
  quantum and priority of the new process and let it run.

- If the child does not inherit a scheduler, it is scheduled by the
  dummy default kernel policy. (servers, drivers, etc.)

- In theory, the scheduler can change the quantum even of the parent
  process and implement any policy for splitting the quantum as
  neither the parent nor the child are runnable.  Sending the
  out-of_quantum message on behalf of the processes may look like the
  right solution, however, the scheduler would probably handle the
  message before the whole fork protocol is finished. This way the
  scheduler has absolute control when the process should become
  runnable.
2010-04-10 15:27:38 +00:00
Tomas Hruby
512058ca98 This tiny cleanup makes the naming a variables in createpde() more clear. 2010-04-10 15:22:41 +00:00
Tomas Hruby
9fdb773cdb A simpler test whether to use kernel's default scheduling
- this is a small addition to the userspace scheduling.
  proc_kernel_scheduler() tests whether to use the default scheduling
  policy in kernel. It is true if the process' scheduler is NULL _or_
  self. Currently none of the tests was complete.
2010-04-10 15:19:25 +00:00
Tomas Hruby
485a037563 do_schedule() cleanup
- it is not neccessary to test whether the scheduler is a system
  process as the process already head permissions to make this call.

- it is better to test whether the scheduler has permission to make
  changes to this process before testing whether the values are valid.
2010-04-10 15:17:09 +00:00
Cristiano Giuffrida
48c6bb79f4 Driver refactory for live update and crash recovery.
SYSLIB CHANGES:
- DS calls to publish / retrieve labels consider endpoints instead of u32_t.

VFS CHANGES:
- mapdriver() only adds an entry in the dmap table in VFS.
- dev_up() is only executed upon reception of a driver up event.

INET CHANGES:
- INET no longer searches for existing drivers instances at startup.
- A newtwork driver is (re)initialized upon reception of a driver up event.
- Networking startup is now race-free by design. No need to waste 5 seconds
at startup any more.

DRIVER CHANGES:
- Every driver publishes driver up events when starting for the first time or
in case of restart when recovery actions must be taken in the upper layers.
- Driver up events are published by drivers through DS. 
- For regular drivers, VFS is normally the only subscriber, but not necessarily.
For instance, when the filter driver is in use, it must subscribe to driver
up events to initiate recovery.
- For network drivers, inet is the only subscriber for now.
- Every VFS driver is statically linked with libdriver, every network driver
is statically linked with libnetdriver.

DRIVER LIBRARIES CHANGES:
- Libdriver is extended to provide generic receive() and ds_publish() interfaces
for VFS drivers.
- driver_receive() is a wrapper for sef_receive() also used in driver_task()
to discard spurious messages that were meant to be delivered to a previous
version of the driver.
- driver_receive_mq() is the same as driver_receive() but integrates support
for queued messages.
- driver_announce() publishes a driver up event for VFS drivers and marks
the driver as initialized and expecting a DEV_OPEN message.
- Libnetdriver is introduced to provide similar receive() and ds_publish()
interfaces for network drivers (netdriver_announce() and netdriver_receive()).
- Network drivers all support live update with no state transfer now.

KERNEL CHANGES:
- Added kernel call statectl for state management. Used by driver_announce() to
unblock eventual callers sendrecing to the driver.
2010-04-08 13:41:35 +00:00
Tomas Hruby
25f2145956 Fixed a panic message
- exceptions cannot occur in kernel tasks as we don't have kernel
  tasks anymore
2010-04-07 12:50:43 +00:00
Kees van Reeuwijk
94a81c840a Removed unused variables, added const where possible. 2010-04-07 11:25:51 +00:00
Tomas Hruby
b464da5d73 do_nice.c
- this file is not used and should have been remove in r6557
2010-04-06 13:44:03 +00:00
Tomas Hruby
987b87e2ad Small fixes
- do_sync_ipc() is private

- fixed typo in a comment
2010-04-06 11:29:31 +00:00
Tomas Hruby
a774cc832f do_ipc() rearrangements
this patch does not add or change any functionality of do_ipc(), it
only makes things a little cleaner (hopefully).

Until now do_ipc() was responsible for handling all ipc calls. The
catch is that SENDA is fairly different which results in some ugly
code like this typecasting and variables naming which does not make
much sense for SENDA and makes the code hard to read.

result = mini_senda(caller_ptr, (asynmsg_t *)m_ptr, (size_t)src_dst_e);

As it is called directly from assembly, the new do_ipc() takes as
input values of 3 registers in reg_t variables (it used to be 4,
however, bit_map wasn't used so I removed it), does the checks common
to all ipc calls and call the appropriate handler either for
do_sync_ipc() (all except SENDA) or mini_senda() (for SENDA) while
typecasting the reg_t values correctly. As a result, handling SENDA
differences in do_sync_ipc() is no more needed. Also the code that
uses msg_size variable is improved a little bit.

arch_do_syscall() is simplified too.
2010-04-06 11:24:26 +00:00
Tomas Hruby
b0d37b81c4 RTS_SYS_LOCK and do_runctl()
- No need for RTS_SYS_LOCK as there are no tasks anymore.
2010-04-06 11:18:04 +00:00
Tomas Hruby
cdd6743e88 do_vtimer()
- removed comment which is not true anymore as we don't have any
  tasks. No need to take any special measures.
2010-04-06 11:16:14 +00:00
Arun Thomas
4ed3a0cf3a Convert kernel over to bsdmake 2010-04-01 22:22:33 +00:00
Kees van Reeuwijk
0a04f49d2b Fixed some incorrect uses of printf-like functions. 2010-04-01 14:30:36 +00:00
Kees van Reeuwijk
fc7dced1fa Fix printfs with too few or too many parms, remove unused vars, fix incorrect flag tests, other code cleanup. 2010-04-01 13:25:05 +00:00
Cristiano Giuffrida
d8b42a755d Move kernel signal SIGKNDELAY to system signal SIGSNDELAY and fix broken ptrace. 2010-03-31 08:55:12 +00:00
Kees van Reeuwijk
4865e3f4f9 More use of endpoint_t. Other code cleanup. 2010-03-30 14:07:15 +00:00
Tomas Hruby
63e2d73d1b Fixed brackets in bitmap macros 2010-03-30 08:34:33 +00:00
Ben Gras
f2b87f5fb7 don't print SYSTEM stacktrace on exceptions as it's not scheduled any more. 2010-03-29 15:32:19 +00:00
Tomas Hruby
62203ec287 NOREC_ENTER and NOREC_RETURN checks removed
- the reasons for these checks no longer exist

- these check are problematic on SMP
2010-03-29 11:43:10 +00:00
Tomas Hruby
5b52c5aa02 A reliable way for userspace to check if a msg is from kernel
- IPC_FLG_MSG_FROM_KERNEL status flag is returned to userspace if the
  receive was satisfied by s message which was sent by the kernel on
  behalf of a process. This perfectly reliale information.

- MF_SENDING_FROM_KERNEL flag added to processes to be able to set
  IPC_FLG_MSG_FROM_KERNEL when finishing receive if the receiver
  wasn't ready to receive immediately.

- PM is changed to use this information to confirm that the scheduling
  messages are indeed from the kernel and not faked by a process.

  PM uses sef_receive_status()

- get_work() is removed from PM to make the changes simpler
2010-03-29 11:25:01 +00:00
Tomas Hruby
2521cc6bdf Slightly faster IPC
- there are cycles wasted in the IPC call due to a fairly compliacted
  way of copying messages from userland to kernel. Sometimes this
  complicated way (generic though) is used even for copying within the
  kernel address space, sometimes it is used for copying in case _no_
  copying is necessary. The goal of this patch is to improve this a
  little bit.

- the places where a copy is from user to kernel use the
  copy_msg_from_user() kernel-kernel copies are turned into
  assignments and BuildNotifyMessage uses the delivery buffers to
  avoid copying.

- copy_msg_from_user() was introduced when removing the system task
  and is about 2/3 faster then using the current mechanism
  (phys_copy). It also avoids the PHYS_COPY_CATCH macro. Assignment is
  also faster and no copy is the fastest ;-) so perhaps there will be
  some hardly noticable performance gain besides the clean up.
2010-03-29 11:16:37 +00:00
Tomas Hruby
b4cf88a04f Userspace scheduling
- cotributed by Bjorn Swift

- In this first phase, scheduling is moved from the kernel to the PM
  server. The next steps are to a) moving scheduling to its own server
  and b) include useful information in the "out of quantum" message,
  so that the scheduler can make use of this information.

- The kernel process table now keeps record of who is responsible for
  scheduling each process (p_scheduler). When this pointer is NULL,
  the process will be scheduled by the kernel. If such a process runs
  out of quantum, the kernel will simply renew its quantum an requeue
  it.

- When PM loads, it will take over scheduling of all running
  processes, except system processes, using sys_schedctl().
  Essentially, this only results in taking over init. As children
  inherit a scheduler from their parent, user space programs forked by
  init will inherit PM (for now) as their scheduler.

 - Once a process has been assigned a scheduler, and runs out of
   quantum, its RTS_NO_QUANTUM flag will be set and the process
   dequeued. The kernel will send a message to the scheduler, on the
   process' behalf, informing the scheduler that it has run out of
   quantum. The scheduler can take what ever action it pleases, based
   on its policy, and then reschedule the process using the
   sys_schedule() system call.

- Balance queues does not work as before. While the old in-kernel
  function used to renew the quantum of processes in the highest
  priority run queue, the user-space implementation only acts on
  processes that have been bumped down to a lower priority queue.
  This approach reacts slower to changes than the old one, but saves
  us sending a sys_schedule message for each process every time we
  balance the queues. Currently, when processes are moved up a
  priority queue, their quantum is also renewed, but this can be
  fiddled with.

- do_nice has been removed from kernel. PM answers to get- and
  setpriority calls, updates it's own nice variable as well as the
  max_run_queue. This will be refactored once scheduling is moved to a
  separate server. We will probably have PM update it's local nice
  value and then send a message to whoever is scheduling the process.

- changes to fix an issue in do_fork() where processes could run out
  of quantum but bypassing the code path that handles it correctly.
  The future plan is to remove the policy from do_fork() and implement
  it in userspace too.
2010-03-29 11:07:20 +00:00
Tomas Hruby
a3ffc0f7ad Removed NIL_SYS_PROC and NIL_PROC
- NIL_PROC replaced by simple NULLs
2010-03-28 09:54:32 +00:00
Kees van Reeuwijk
98493805fd Lots of const correctness. 2010-03-27 14:31:00 +00:00
Cristiano Giuffrida
9192dbecc9 Preserve the order of IPC messages between two parties.
Currently a sequence of messages between a sender A and a receiver B of the
form: A.asynsend(M1, B); A.send(M2, B) may result in the receiver receiving
M1 first and then M2 or viceversa. This patch makes sure that the original
order M1, M2 is always preserved.

Note that the order of a hypotetical sequence A.asynsend(M1, B);
A.asynsend(M2, B) is already guaranteed by the implementation of
asynsend by design. Other senda-based wrappers can define their own
semantics.
2010-03-27 00:09:22 +00:00
Tomas Hruby
8e5a82fd49 Comment in proc.h
- This comment is not correct as the pproc_addr array does not exist.
2010-03-26 13:19:04 +00:00
Tomas Hruby
1dd6f5573a Direction flag
- ack assumes that the direction flag in eflags is clear when
  assigning two structures. It is implemented by a call to a built-in
  function which is like memcpy but needs the flag to be clear
  otherwise rubish is copied. This patch fixes the kernel entries.
2010-03-26 12:29:52 +00:00
Tomas Hruby
8451a86f0a Interrupts hadling while idle
- When the cpu halts, the interrupts are enable so the cpu may be
  woken up. When the interrupt handler returns but another interrupt
  is available it is also serviced immediately. This is not a problem
  per-se. It only slightly breaks time accounting as idle accounted is
  for the kernel time in the interrupt handler.
  
  
-  As the big kernel lock is lock/unlocked in the smp branch in the
   time acounting functions as they are called exactly at the places
   we need to take the lock) this leads to a deadlock.

- we make sure that once the interrupt handler returns from the nested
  trap, the interrupts are disabled. This means that only one
  interrupt is serviced after idle is interrupted.

- this requires the loop in apic timer calibration to keep reenabling
  the interrupts. I admit it is a little bit hackish (one line),
  however, this code is a stupid corner case at the boot time.
  Hopefully it does not matter too much.
2010-03-23 13:35:01 +00:00
Cristiano Giuffrida
bde2109b7c IPC status code for receive().
IPC changes:
- receive() is changed to take an additional parameter, which is a pointer to
a status code.
- The status code is filled in by the kernel to provide additional information
to the caller. For now, the kernel only fills in the IPC call used by the
sender.

Syslib changes:
- sef_receive() has been split into sef_receive() (with the original semantics)
and sef_receive_status() which exposes the status code to userland.
- Ideally, every sys process should gradually switch to sef_receive_status()
and use is_ipc_notify() as a dependable way to check for notify.
- SEF has been modified to use is_ipc_notify() and demonstrate how to use the
new status code.
2010-03-23 00:09:11 +00:00