Commit graph

46 commits

Author SHA1 Message Date
David van Moolenbroek
895850b8cf move timers code to libsys 2010-07-09 12:58:18 +00:00
Erik van der Kouwe
23284ee7bd User-space scheduling for system processes 2010-07-01 08:32:33 +00:00
Arun Thomas
1bf6d23f34 Make exec() use entry point in a.out header 2010-06-10 14:59:10 +00:00
Arun Thomas
eec65ac664 Rename tell_fs to tell_vfs 2010-06-09 14:31:30 +00:00
Tomas Hruby
b09bcf6779 Scheduling server (by Bjorn Swift)
In this second phase, scheduling is moved from PM to its own
scheduler (see r6557 for phase one). In the next phase we hope to a)
include useful information in the "out of quantum" message and b)
create some simple scheduling policy that makes use of that
information.

When the system starts up, PM will iterate over its process table and
ask SCHED to take over scheduling unprivileged processes. This is
done by sending a SCHEDULING_START message to SCHED. This message
includes the processes endpoint, the parent's endpoint and its nice
level. The scheduler adds this process to its schedproc table, issues
a schedctl, and returns its own endpoint to PM - as the endpoint of
the effective scheduler. When a process terminates, a SCHEDULING_STOP
message is sent to the scheduler.

The reason for this effective endpoint is for future compatibility.
Some day, we may have a scheduler that, instead of scheduling the
process itself, forwards the SCHEDULING_START message on to another
scheduler.

PM has information on who schedules whom. As such, scheduling
messages from user-land are sent through PM. An example is when
processes change their priority, using nice(). In that case, a
getsetpriority message is sent to PM, which then sends a
SCHEDULING_SET_NICE to the process's effective scheduler.

When a process is forked through PM, it inherits its parent's
scheduler, but is spawned with an empty quantum. As before, a request
to fork a process flows through VM before returning to PM, which then
wakes up the child process. This flow has been modified slightly so
that PM notifies the scheduler of the new process, before waking up
the child process. If the scheduler fails to take over scheduling,
the child process is torn down and the fork fails with an erroneous
value.

Process priority is entirely decided upon using nice levels. PM
stores a copy of each process's nice level and when a child is
forked, its parent's nice level is sent in the SCHEDULING_START
message. How this level is mapped to a priority queue is up to the
scheduler. It should be noted that the nice level is used to
determine the max_priority and the parent could have been in a lower
priority when it was spawned. To prevent a CPU intensive process from
hawking the CPU by continuously forking children that get scheduled
in the max_priority, the scheduler should determine in which queue
the parent is currently scheduled, and schedule the child in that
same queue.

Other fixes: The USER_Q in kernel/proc.h was incorrectly defined as
NR_SCHED_QUEUES/2. That results in a "off by one" error when
converting priority->nice->priority for nice=0. This also had the
side effect that if someone were to set the MAX_USER_Q to something
else than 0, then USER_Q would be off.
2010-05-18 13:39:04 +00:00
Erik van der Kouwe
93f3bf5bda Fix wrong word 2010-04-28 20:37:08 +00:00
Tomas Hruby
1a31d158ad Restructure and simplyfycation of the scheduling code in PM a little bit.
- It introduces schedule_process() which makes a kernel call to set
  the scheduling parameters of a process. It is used in the next patch.
2010-04-10 15:24:49 +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
Cristiano Giuffrida
cb176df60f New RS and new signal handling for system processes.
UPDATING INFO:
20100317:
        /usr/src/etc/system.conf updated to ignore default kernel calls: copy
        it (or merge it) to /etc/system.conf.
        The hello driver (/dev/hello) added to the distribution:
        # cd /usr/src/commands/scripts && make clean install
        # cd /dev && MAKEDEV hello

KERNEL CHANGES:
- Generic signal handling support. The kernel no longer assumes PM as a signal
manager for every process. The signal manager of a given process can now be
specified in its privilege slot. When a signal has to be delivered, the kernel
performs the lookup and forwards the signal to the appropriate signal manager.
PM is the default signal manager for user processes, RS is the default signal
manager for system processes. To enable ptrace()ing for system processes, it
is sufficient to change the default signal manager to PM. This will temporarily
disable crash recovery, though.
- sys_exit() is now split into sys_exit() (i.e. exit() for system processes,
which generates a self-termination signal), and sys_clear() (i.e. used by PM
to ask the kernel to clear a process slot when a process exits).
- Added a new kernel call (i.e. sys_update()) to swap two process slots and
implement live update.

PM CHANGES:
- Posix signal handling is no longer allowed for system processes. System
signals are split into two fixed categories: termination and non-termination
signals. When a non-termination signaled is processed, PM transforms the signal
into an IPC message and delivers the message to the system process. When a
termination signal is processed, PM terminates the process.
- PM no longer assumes itself as the signal manager for system processes. It now
makes sure that every system signal goes through the kernel before being
actually processes. The kernel will then dispatch the signal to the appropriate
signal manager which may or may not be PM.

SYSLIB CHANGES:
- Simplified SEF init and LU callbacks.
- Added additional predefined SEF callbacks to debug crash recovery and
live update.
- Fixed a temporary ack in the SEF init protocol. SEF init reply is now
completely synchronous.
- Added SEF signal event type to provide a uniform interface for system
processes to deal with signals. A sef_cb_signal_handler() callback is
available for system processes to handle every received signal. A
sef_cb_signal_manager() callback is used by signal managers to process
system signals on behalf of the kernel.
- Fixed a few bugs with memory mapping and DS.

VM CHANGES:
- Page faults and memory requests coming from the kernel are now implemented
using signals.
- Added a new VM call to swap two process slots and implement live update.
- The call is used by RS at update time and in turn invokes the kernel call
sys_update().

RS CHANGES:
- RS has been reworked with a better functional decomposition.
- Better kernel call masks. com.h now defines the set of very basic kernel calls
every system service is allowed to use. This makes system.conf simpler and
easier to maintain. In addition, this guarantees a higher level of isolation
for system libraries that use one or more kernel calls internally (e.g. printf).
- RS is the default signal manager for system processes. By default, RS
intercepts every signal delivered to every system process. This makes crash
recovery possible before bringing PM and friends in the loop.
- RS now supports fast rollback when something goes wrong while initializing
the new version during a live update.
- Live update is now implemented by keeping the two versions side-by-side and
swapping the process slots when the old version is ready to update.
- Crash recovery is now implemented by keeping the two versions side-by-side
and cleaning up the old version only when the recovery process is complete.

DS CHANGES:
- Fixed a bug when the process doing ds_publish() or ds_delete() is not known
by DS.
- Fixed the completely broken support for strings. String publishing is now
implemented in the system library and simply wraps publishing of memory ranges.
Ideally, we should adopt a similar approach for other data types as well.
- Test suite fixed.

DRIVER CHANGES:
- The hello driver has been added to the Minix distribution to demonstrate basic
live update and crash recovery functionalities.
- Other drivers have been adapted to conform the new SEF interface.
2010-03-17 01:15:29 +00:00
Thomas Veerman
bef0e3eb63 - Add support for the ucontext system calls (getcontext, setcontext,
swapcontext, and makecontext).
- Fix VM to not erroneously think the stack segment and data segment have
  collided when a user-space thread invokes brk().
- Add test51 to test ucontext functionality.
- Add man pages for ucontext system calls.
2010-03-12 15:58:41 +00:00
Erik van der Kouwe
c107dbe1d0 Man-pages on mkdep, cdprobe, loadramdisk and newroot; thanks to Antoine Leca 2010-02-02 15:10:00 +00:00
David van Moolenbroek
ac9ab099c8 General cleanup:
- clean up kernel section of minix/com.h somewhat
- remove ALLOCMEM and VM_ALLOCMEM calls
- remove non-safecopy and minix-vmd support from Inet
- remove SYS_VIRVCOPY and SYS_PHYSVCOPY calls
- remove obsolete segment encoding in SYS_SAFECOPY*
- remove DEVCTL call, svrctl(FSDEVUNMAP), map_driverX
- remove declarations of unimplemented svrctl requests
- remove everything related to swapping to disk
- remove floppysetup.sh
- remove traces of rescue device
- update DESCRIBE.sh with new devices
- some other small changes
2010-01-05 19:39:27 +00:00
David van Moolenbroek
f89388c241 Kernel, servers: remove unused proto.h definitions 2009-10-31 14:11:50 +00:00
David van Moolenbroek
4c263d6002 PM: clean up endpoint info API/ABI 2009-10-31 14:09:28 +00:00
David van Moolenbroek
b423d7b477 Merge of David's ptrace branch. Summary:
o Support for ptrace T_ATTACH/T_DETACH and T_SYSCALL
o PM signal handling logic should now work properly, even with debuggers
  being present
o Asynchronous PM/VFS protocol, full IPC support for senda(), and
  AMF_NOREPLY senda() flag

DETAILS

Process stop and delay call handling of PM:
o Added sys_runctl() kernel call with sys_stop() and sys_resume()
  aliases, for PM to stop and resume a process
o Added exception for sending/syscall-traced processes to sys_runctl(),
  and matching SIGKREADY pseudo-signal to PM
o Fixed PM signal logic to deal with requests from a process after
  stopping it (so-called "delay calls"), using the SIGKREADY facility
o Fixed various PM panics due to race conditions with delay calls versus
  VFS calls
o Removed special PRIO_STOP priority value
o Added SYS_LOCK RTS kernel flag, to stop an individual process from
  running while modifying its process structure

Signal and debugger handling in PM:
o Fixed debugger signals being dropped if a second signal arrives when
  the debugger has not retrieved the first one
o Fixed debugger signals being sent to the debugger more than once
o Fixed debugger signals unpausing process in VFS; removed PM_UNPAUSE_TR
  protocol message
o Detached debugger signals from general signal logic and from being
  blocked on VFS calls, meaning that even VFS can now be traced
o Fixed debugger being unable to receive more than one pending signal in
  one process stop
o Fixed signal delivery being delayed needlessly when multiple signals
  are pending
o Fixed wait test for tracer, which was returning for children that were
  not waited for
o Removed second parallel pending call from PM to VFS for any process
o Fixed process becoming runnable between exec() and debugger trap
o Added support for notifying the debugger before the parent when a
  debugged child exits
o Fixed debugger death causing child to remain stopped forever
o Fixed consistently incorrect use of _NSIG

Extensions to ptrace():
o Added T_ATTACH and T_DETACH ptrace request, to attach and detach a
  debugger to and from a process
o Added T_SYSCALL ptrace request, to trace system calls
o Added T_SETOPT ptrace request, to set trace options
o Added TO_TRACEFORK trace option, to attach automatically to children
  of a traced process
o Added TO_ALTEXEC trace option, to send SIGSTOP instead of SIGTRAP upon
  a successful exec() of the tracee
o Extended T_GETUSER ptrace support to allow retrieving a process's priv
  structure
o Removed T_STOP ptrace request again, as it does not help implementing
  debuggers properly
o Added MINIX3-specific ptrace test (test42)
o Added proper manual page for ptrace(2)

Asynchronous PM/VFS interface:
o Fixed asynchronous messages not being checked when receive() is called
  with an endpoint other than ANY
o Added AMF_NOREPLY senda() flag, preventing such messages from
  satisfying the receive part of a sendrec()
o Added asynsend3() that takes optional flags; asynsend() is now a
  #define passing in 0 as third parameter
o Made PM/VFS protocol asynchronous; reintroduced tell_fs()
o Made PM_BASE request/reply number range unique
o Hacked in a horrible temporary workaround into RS to deal with newly
  revealed RS-PM-VFS race condition triangle until VFS is asynchronous

System signal handling:
o Fixed shutdown logic of device drivers; removed old SIGKSTOP signal
o Removed is-superuser check from PM's do_procstat() (aka getsigset())
o Added sigset macros to allow system processes to deal with the full
  signal set, rather than just the POSIX subset

Miscellaneous PM fixes:
o Split do_getset into do_get and do_set, merging common code and making
  structure clearer
o Fixed setpriority() being able to put to sleep processes using an
  invalid parameter, or revive zombie processes
o Made find_proc() global; removed obsolete proc_from_pid()
o Cleanup here and there

Also included:
o Fixed false-positive boot order kernel warning
o Removed last traces of old NOTIFY_FROM code

THINGS OF POSSIBLE INTEREST

o It should now be possible to run PM at any priority, even lower than
  user processes
o No assumptions are made about communication speed between PM and VFS,
  although communication must be FIFO
o A debugger will now receive incoming debuggee signals at kill time
  only; the process may not yet be fully stopped
o A first step has been made towards making the SYSTEM task preemptible
2009-09-30 09:57:22 +00:00
Ben Gras
32fa22fc2d RS_LOOKUP feature for libc functions that want to access servers.
let ipc talk to all USER processes and vice versa.

pm sig wrapper notify has to be called from two files.

actually install include files.
2009-09-21 15:25:15 +00:00
David van Moolenbroek
323f0abdd6 Support for setitimer(ITIMER_VIRTUAL/ITIMER_PROF). New test (41) for setitimer. 2009-08-15 21:37:26 +00:00
David van Moolenbroek
d82e260a90 Support for setitimer(ITIMER_REAL). 2009-08-15 16:09:32 +00:00
David van Moolenbroek
1a9e07b0e5 PM: fix ptrace(T_EXIT) 'exit_proc: not idle' race condition. 2009-07-11 13:22:56 +00:00
David van Moolenbroek
67d986f882 PM cleanup: merge exit and coredump paths 2009-07-08 17:16:53 +00:00
Ben Gras
c078ec0331 Basic VM and other minor improvements.
Not complete, probably not fully debugged or optimized.
2008-11-19 12:26:10 +00:00
David van Moolenbroek
f73b541952 Backport of fix from asynchvfs branch for PM-LOG-VFS-PM deadlock that resulted in VFS panics. 2008-06-24 13:53:03 +00:00
Philip Homburg
1cffa69d2c Support for I/O MMU: do not re-use a memory segment until the I/O MMU has
removed it from its map.
2008-02-21 16:33:34 +00:00
Philip Homburg
69ca935251 getpeuid implementation. Get the uid of a process (by endpoint) 2007-04-27 12:21:06 +00:00
Ben Gras
7195fe3325 System statistical and call profiling
support by Rogier Meurs <rogier@meurs.org>.
2006-10-30 15:53:38 +00:00
Ben Gras
18327f02a8 Introduced unprivileged getsysinfo variant, to retrieve harmless data
in formats that don't change (or is upwards compatible).
2006-07-27 16:23:01 +00:00
Ben Gras
b5179d7025 Split do_brk in a stub and a function that does the real work, so that
the real work can be called from elsewhere too. Specifically, to allow PM
its own brk().
2006-06-30 14:35:38 +00:00
Philip Homburg
e9aabcf2f8 Disabled building rescue driver (no longer needed). Moved allocmem from
library to the memory driver. Always put output from within TTY directly on
the console. Removed second include of driver.h from tty.c. Made tty_inrepcode
bigger. First step to move PM and FS calls that are not regular (API)
system calls out of callnr.h (renumbered them, and removed them from the
table.c files). Imported the Minix-vmd uname implementation. This provides
a more stable ABI than the current implementation. Added a bit of security
checking. Unfortunately not nearly enough to get a secure system. Fixed a
bug related to the sizes of the programs in the image (in PM patch_mem_chunks).
2006-05-19 12:19:37 +00:00
Philip Homburg
773844a816 New interface between PM and FS. 2006-05-11 14:57:23 +00:00
Jorrit Herder
021e3234d8 Jorrit's ... "progress?" 2006-03-10 16:10:05 +00:00
Ben Gras
7967177710 endpoint-aware conversion of servers.
'who', indicating caller number in pm and fs and some other servers, has
been removed in favour of 'who_e' (endpoint) and 'who_p' (proc nr.).

In both PM and FS, isokendpt() convert endpoints to process slot
numbers, returning OK if it was a valid and consistent endpoint number.
okendpt() does the same but panic()s if it doesn't succeed. (In PM,
this is pm_isok..)

pm and fs keep their own records of process endpoints in their proc tables,
which are needed to make kernel calls about those processes.

message field names have changed.

fs drivers are endpoints.

fs now doesn't try to get out of driver deadlock, as the protocol isn't
supposed to let that happen any more. (A warning is printed if ELOCKED
is detected though.)

fproc[].fp_task (indicating which driver the process is suspended on)
became an int.

PM and FS now get endpoint numbers of initial boot processes from the
kernel. These happen to be the same as the old proc numbers, to let
user processes reach them with the old numbers, but FS and PM don't know
that. All new processes after INIT, even after the generation number
wraps around, get endpoint numbers with generation 1 and higher, so
the first instances of the boot processes are the only processes ever
to have endpoint numbers in the old proc number range.

More return code checks of sys_* functions have been added.

IS has become endpoint-aware. Ditched the 'text' and 'data' fields
in the kernel dump (which show locations, not sizes, so aren't terribly
useful) in favour of the endpoint number. Proc number is still visible.

Some other dumps (e.g. dmap, rs) show endpoint numbers now too which got
the formatting changed.

PM reading segments using rw_seg() has changed - it uses other fields
in the message now instead of encoding the segment and process number and
fd in the fd field. For that it uses _read_pm() and _write_pm() which to
_taskcall()s directly in pm/misc.c.

PM now sys_exit()s itself on panic(), instead of sys_abort().

RS also talks in endpoints instead of process numbers.
2006-03-03 10:20:58 +00:00
Ben Gras
4bae163d37 High watermark memory usage feature 2005-10-18 17:21:11 +00:00
Ben Gras
abd0b53e0a PM: added possibility to copy hole list from alloc.c to outside, for
misc.c to copy it away by getsysinfo
IS: prints out hole list + stats such as largest contiguous chunk
2005-10-13 12:48:43 +00:00
Jorrit Herder
46c8884e36 Cleanup with gcc. Removed unused variables.
Fixed some uninitialized problems.
2005-08-25 12:05:09 +00:00
Jorrit Herder
ab732a37e8 Renamed mm_exit to pm_exit (requested by Al)
Small cleanup in pm_init.
2005-08-10 09:37:54 +00:00
Jorrit Herder
570eac1f53 Renamed system library functionality.
Updated debug dumps of IS server.
2005-07-14 15:16:12 +00:00
Ben Gras
f0817fbd4c complete, tick-resolution gettimeofday() implementation 2005-07-06 07:08:36 +00:00
Ben Gras
9cf24c3233 Calls and functionality for get/setpriority() and fsync(). 2005-07-01 17:58:29 +00:00
Jorrit Herder
92f9bd02f8 Parsing of free memory chunks is now done at the process manager. 2005-06-17 09:10:30 +00:00
Jorrit Herder
f2a85e58d9 Various updates.
* Removed some variants of the SYS_GETINFO calls from the kernel;
  replaced them with new PM and utils libary functionality. Fixed
  bugs in utils library that used old get_kenv() variant.
* Implemented a buffer in the kernel to gather random data.
  Memory driver periodically checks this for /dev/random.
  A better random algorithm can now be implemented in the driver.
  Removed SYS_RANDOM; the SYS_GETINFO call is used instead.
* Remove SYS_KMALLOC from the kernel. Memory allocation can now
  be done at the process manager with new 'other' library functions.
2005-06-03 13:55:06 +00:00
Jorrit Herder
e782e76944 Created new findproc system call to the PM (to replace similar kernel
functionality). Currently working on memory allocation (not yet finished).
2005-06-02 12:43:21 +00:00
Jorrit Herder
6d23f072f3 Cleaned up src/lib/utils library. Renamed server_ functions to more logical
names. All system processes can now either use panic() or report() from
libutils, or redefine their own function. Assertions are done via the standard
<assert.h> functionality.
2005-06-01 14:31:00 +00:00
Jorrit Herder
322ec9ef8b Moved stime, time, times POSIX calls from FS to PM. Removed child time
accounting from kernel (now in PM).  Large amount of files in this commit
is due to system time problems during development.
2005-05-31 09:50:51 +00:00
Jorrit Herder
1cb880b158 Intermediate update---please await next commit. 2005-05-19 09:36:44 +00:00
Jorrit Herder
1ecc6bf3b3 Removed 'system process' magic from PM and FS. 2005-05-13 08:57:08 +00:00
Ben Gras
0e9261ed5a Rename mm (memory manager) to pm (process manager), involved renaming
dir..
2005-05-03 15:35:52 +00:00