Commit graph

30 commits

Author SHA1 Message Date
Erik van der Kouwe
ff835e0e35 use the verbose=2 boot monitor setting to get extensive output for debugging 2010-02-13 22:11:16 +00:00
Kees van Reeuwijk
b67f788eea Removed a number of useless #includes 2010-01-26 10:59:01 +00:00
Tomas Hruby
5efa92f754 NMI watchdog is an awesome feature for debugging locked up kernels.
There is not that much use for it on a single CPU, however, deadlock
between kernel and system task can be delected. Or a runaway loop.

If a kernel gets locked up the timer interrupts don't occure (as all
interrupts are disabled in kernel mode). The only chance is to
interrupt the kernel by a non-maskable interrupt.

This patch generates NMIs using performance counters. It uses the most
widely available performace counters. As the performance counters are 
highly model-specific this patch is not guaranteed to work on every
machine.  Unfortunately this is also true for KVM :-/ On the other
hand adding this feature for other models is not extremely difficult
and the framework makes it hopefully easy enough.

Depending on the frequency of the CPU an NMI is generated at most
about every 0.5s If the cpu's speed is less then 2Ghz it is generated
at most every 1s. In general an NMI is generated much less often as
the performance counter counts down only if the cpu is not idle.
Therefore the overhead of this feature is fairly minimal even if the
load is high.

Uppon detecting that the kernel is locked up the kernel dumps the 
state of the kernel registers and panics.

Local APIC must be enabled for the watchdog to work.

The code is _always_ compiled in, however, it is only enabled if  
watchdog=<non-zero> is set in the boot monitor.

One corner case is serial console debugging. As dumping a lot of stuff
to the serial link may take a lot of time, the watchdog does not 
detect lockups during this time!!! as it would result in too many
false positives. 10 nmi have to be handled before the lockup is
detected. This means something between ~5s to 10s.

Another corner case is that the watchdog is enabled only after the
paging is enabled as it would be pure madness to try to get it right.
2010-01-16 20:53:55 +00:00
Tomas Hruby
a316221fbf Local apic is dissabled by default
to enable it set no_apic=0 in the boot monitor
2010-01-11 17:21:19 +00:00
Tomas Hruby
8a44a44cb9 Local APIC
- local APIC timer used as the source of time

- PIC is still used as the hw interrupt controller as we don't have
  enough info without ACPI or MPS to set up IO APICs

- remapping of APIC when switching paging on, uses the new mechanism
  to tell VM what phys areas to map in kernel's virtual space

- one more step to SMP

based on code by Arun C.
2009-11-16 21:41:44 +00:00
Tomas Hruby
ae75f9d4e5 Removal of the executable flag from files that cannot be executed
- 755 -> 644
2009-11-09 10:26:00 +00:00
Ben Gras
24e1e83028 really revert endpoint_t -> int
debugging info on panic: decode segment selectors and descriptors, now moved
to arch-specific part, prototypes added; sanity checking in debug.h made
optional with vmassert().
2009-10-05 15:47:23 +00:00
Tomas Hruby
2e293ce7c0 system_init() renamed to arch_init()
- a better name for architecture specific init function

- some of x86 init code must execute in protected mode

- prot_init() removed from this function and still called in cstart() Imho this
  should be called from the architecture specific assembly not cstart. cstart
  perform Minix monitor specific tasks and will be touched once another
  bootloader is in use, e.g. booting via tftp, therefore we keep it as is for
  now.

- this is a backport from the SMP code which requires this. Merging will be simpler
2009-08-30 14:55:30 +00:00
Ben Gras
d5f978411e use #include name for servarname 2009-01-11 23:45:29 +00:00
Ben Gras
b740ff055f if serial output is enabled in the boot monitor, on the first serial line,
enable serial debug output in the kernel too.
2008-12-19 13:21:42 +00:00
Ben Gras
c4fb567bd5 . replace HZ by runtime system_hz (sysenv variable 'hz')
. new flag PROC_FULLVM in table indicating process wants full address
   space (this is then created and managed by VM)
2008-12-11 14:15:23 +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
Ben Gras
6f77685609 Split of architecture-dependent and -independent functions for i386,
mainly in the kernel and headers. This split based on work by
Ingmar Alting <iaalting@cs.vu.nl> done for his Minix PowerPC architecture
port.

 . kernel does not program the interrupt controller directly, do any
   other architecture-dependent operations, or contain assembly any more,
   but uses architecture-dependent functions in arch/$(ARCH)/.
 . architecture-dependent constants and types defined in arch/$(ARCH)/include.
 . <ibm/portio.h> moved to <minix/portio.h>, as they have become, for now,
   architecture-independent functions.
 . int86, sdevio, readbios, and iopenable are now i386-specific kernel calls
   and live in arch/i386/do_* now.
 . i386 arch now supports even less 86 code; e.g. mpx86.s and klib86.s have
   gone, and 'machine.protected' is gone (and always taken to be 1 in i386).
   If 86 support is to return, it should be a new architecture.
 . prototypes for the architecture-dependent functions defined in
   kernel/arch/$(ARCH)/*.c but used in kernel/ are in kernel/proto.h
 . /etc/make.conf included in makefiles and shell scripts that need to
   know the building architecture; it defines ARCH=<arch>, currently only
   i386.
 . some basic per-architecture build support outside of the kernel (lib)
 . in clock.c, only dequeue a process if it was ready
 . fixes for new include files

files deleted:
 . mpx/klib.s - only for choosing between mpx/klib86 and -386
 . klib86.s - only for 86

i386-specific files files moved (or arch-dependent stuff moved) to arch/i386/:
 . mpx386.s (entry point)
 . klib386.s
 . sconst.h
 . exception.c
 . protect.c
 . protect.h
 . i8269.c
2006-12-22 15:22:27 +00:00
Ben Gras
eecb40cf21 Rename protected to prot for g++ 2006-06-20 09:52:11 +00:00
Ben Gras
eae250dea4 . load average calculation changed to calculate it all over every tick
instead of keeping a running total of enqueued processes
   (because somehow the load average was broken)
 . added SI_KPROC_TAB to get a copy of kernel process table from PM, for
   a top implementation
 . fixed arg to sys_nice() to make it an endpoint, not a slot number
2006-03-16 09:33:35 +00:00
Ben Gras
87f2236ad2 load average measurement implementation, accessable through
getloadavg() system call in the library.
2005-11-14 15:50:46 +00:00
Ben Gras
5ae6f98dea Andy's formatting fixes. 2005-09-11 16:44:06 +00:00
Ben Gras
d11b2e4b8c Al's double-blank-line removal request 2005-08-22 15:23:47 +00:00
Jorrit Herder
89cf745fe2 Single boot driver loaded, while multiple can be included in the boot image.
The user needs to set label=... to choose the driver of his or her choice.
This driver will be mapped onto the controller that is set in controller=...

Minor cleanup of kernel source code (boot image table now is static).
2005-08-03 16:06:35 +00:00
Jorrit Herder
c0718054e9 Various fixes and improvements.
- fixed bug that caused IDLE to panic (irq hook inconsistency);
- kprintf() now accepts multiple arguments; moved to utility.c;
- prepare_shutdown() signals system processes with SIGKSTOP;
- phys_fill() renamed to phys_memset(), argument order changed;
- kmemset() removed in favor of phys_kmemset();
- kstrncpy() removed in favor of phys_copy();
- katoi, kstrncmp replaced by normal library procedure again;
- rm_irq_handler() interface changed (simply pass hook pointer);
2005-07-20 15:25:38 +00:00
Jorrit Herder
1d7bdd4ab1 *** empty log message *** 2005-07-19 15:01:47 +00:00
Ben Gras
f96645a4eb Fixed a bug in kstrncpy() that caused mayhem whenever the buffer to be
copied into was the same size as the source string - it will keep on
filling with zeroes forever. This was a signed/unsigned bug, fixed by
making the kstrncpy argument ssize_t instead of size_t. This bug was
triggered by Chris Young <teddga@earthlink.net>, by dazzling coincedence -
changing OS_VERSION into something with one more character (exactly the
same size as the buffer in the kinfo struct).

Also noticed that the kstrncpy() call didn't null-terminate the strings
if necessary, also fixed.
2005-07-13 14:46:11 +00:00
Jorrit Herder
a408699ce0 Cleaned up process table structure: removed p_type, p_pendcount.
Removed stop sequence when MINIX is shut down.
Disabled send mask checks --- to be replaced by proper mechanism.
Fixed bug relating to 'shutdown -x'.
Simplified clock accounting of realtime.
Updated Makefiles for mkdept script.
2005-06-24 16:24:40 +00:00
Ben Gras
3bb4d191d7 Corrected buffer size calculation from MAX(bufsize,realsize)
to MIN(bufsize,realsize) while copying boot params.
2005-06-21 16:18:23 +00:00
Jorrit Herder
355a10864b Fixed various GCC compiler warnings for the kernel.
Only main() now gives a warning about the return type (GCC wants an int).
2005-06-21 10:47:46 +00:00
Jorrit Herder
e0a98a4d65 * Fixed bug relating to nested locking in interrupt handlers. The nested lock
caused interrupts to be reenabled (due to unlock), which caused a race. The
problems were especially visible on slower machines.
* Relocated free memory parsing to process manager. This saved quite some
code at the kernel level. Text size was reduced by about 650 bytes.
* Removed locks for updating the realtime in the clock's main loop and the
get_uptime function. Interrupts are no longer reentrant, so realtime is
immediately updated.
2005-06-17 09:09:54 +00:00
Jorrit Herder
0e2a7a9730 Kernel cleanup.
Reduced kernel size by 512KB by moving private buffer into cstart() function.
Replaced assertions with erroneous return values. Removed assertions relating
to isuserp(rp), since all processes should become user processes; system
processes are now treated similar to other processes.
2005-06-07 12:34:25 +00:00
Jorrit Herder
614f49b557 Fixed some comments and reorganized some code.
Fixed minor bug in notify() function.
2005-05-18 10:36:23 +00:00
Jorrit Herder
89ac678b9b *** empty log message *** 2005-04-29 15:36:43 +00:00
Ben Gras
9865aeaa79 Initial revision 2005-04-21 14:53:53 +00:00