Commit graph

17 commits

Author SHA1 Message Date
Arun Thomas
93ae43f577 boot: Add multiboot support
Not yet fully spec-compliant; work in progress
2011-06-24 17:21:51 +02:00
Ben Gras
a77c2973b3 fix clang warnings -R in kernel/ and servers/ 2011-06-09 16:09:13 +02:00
Ben Gras
dc1cc91df1 <ansi.h> -> <minix/ansi.h> 2011-01-28 11:35:02 +00:00
Tomas Hruby
1f89845bb2 SMP - can boot even if some cpus fail to boot
- EBADCPU is returned is scheduler tries to run a process on a CPU
  that either does not exist or isn't booted

- this change was originally meant to deal with stupid cpuid
  instruction which provides totally useless information about
  hyper-threading and MPS which does not deal with ht at all. ACPI
  provides correct information. If ht is turned off it looks like some
  CPUs failed to boot.  Nevertheless this patch may be handy for
  testing/benchmarking in the future.
2010-09-15 14:11:21 +00:00
Tomas Hruby
e87d29171f SMP - Compiles for both single and multi processor again
- this patch adds various fixes as some of the previous patches break
  compilations without CONFIG_SMP being set
2010-09-15 14:11:03 +00:00
Tomas Hruby
311f145bc7 SMP - Balancing run queues for SMP
- it preempts running processes though :( this is not the final
  solution
2010-09-15 14:10:51 +00:00
Tomas Hruby
06b6e5624a SMP - Changed prototype of sys_schedule()
- sys_schedule can change only selected values, -1 means that the
  current value should be kept unchanged. For instance we mostly want
  to change the scheduling quantum and priority but we want to keep
  the process at the current cpu

- RS can hand off its processes to scheduler

- service can read the destination cpu from system.conf

- RS can pass the information farther
2010-09-15 14:10:42 +00:00
Tomas Hruby
1e273f640e SMP - Scheduler can assign process to a cpu
- machine information contains the number of cpus and the bsp id

- a dummy SMP scheduler which keeps all system processes on BSP and
  all other process on APs. The scheduler remembers how many processes
  are assigned to each CPU and always picks the one with the least
  processes for a new process.
2010-09-15 14:10:33 +00:00
Tomas Hruby
7f47f4174d Fixed comments in sched
- not only PM can send sched requests. RS too.
2010-07-16 09:40:12 +00:00
Cristiano Giuffrida
8cedace2f5 Scheduling parameters out of the kernel. 2010-07-13 15:30:17 +00:00
David van Moolenbroek
895850b8cf move timers code to libsys 2010-07-09 12:58:18 +00:00
Thomas Veerman
34a2864e27 Fix a few compile time warnings 2010-07-02 12:41:19 +00:00
Erik van der Kouwe
23284ee7bd User-space scheduling for system processes 2010-07-01 08:32:33 +00:00
Arun Thomas
c0c8d25799 Rename mkfiles from minix.*.mk to bsd.*.mk
Makes things easier for pkgsrc
2010-06-25 18:29:09 +00:00
Erik van der Kouwe
498d7d8a4c Don't use kernel responses in servers 2010-06-24 07:37:26 +00:00
Tomas Hruby
a8111c5027 Various small scheduling related fixes 2010-05-26 07:16:39 +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