to this when raised, and most were in favor of at least this option
(some also asked for semaphores and messages, but I'll leave that argument
for another time :).
this code is controlled by smptests.h: TEST_CPUSTOP, OFF by default
new code for handling mixed-mode 8259/APIC programming without 'ExtInt'
this code is controlled by smptests.h: TEST_ALTTIMER, ON by default
- TEST_CPUSTOP adds stop_cpus()/restart_cpus(), OFF by default
- TEST_ALTTIMER new method for attaching 8259 PIC to APIC
this method avoids 'ExtInt' programming, ON by default
- TIMER_ALL sends 8259/8254 timer INTs to all CPUs, ON by default
- ASMPOSTCODExxx code to display bytes to POST hardware, OFF by default
because there was no non-inline spl0() to call.
Don't frob intr_nesting_level in idle() or cpu_switch(). Interrupts
are mostly disabled then, so the frobbing had little effect.
- added Xcpustop IPI code to support stop_cpus()/restart_cpus().
it is off by default, enable via smptests.h:TEST_CPUSTOP
intr_machdep.h:
- moved +ICULEN to lower level.
- added entry for Xcpustop.
General cleanup.
New functions to stop/start CPUs via IPIs:
- int stop_cpus( u_int map );
- int restart_cpus( u_int map );
Turned off by default, enabled via smptests.h:TEST_CPUSTOP.
Current version has a BUG, perhaps a deadlock?
This variable is a bitmap showing all CPUs present EXCEPT the CPU
owning the variable. In other words, it is equal to the global bitmap
'all_cpus' minus its own bit.
Till now NMIs would be ignored. Now an NMI is caught by the BSP.
APs still ignore NMI, am working on code to allow a CPU to stop other CPUs
via an IPI.
available to the kernel (VM_KMEM_SIZE). The default (32 MB) is too low
when having 512 MB or more physical memory in a server environment. This is
relevant on systems where "panic: kmem_malloc: kmem_map too small" is a
problem.
value (200) is too low in some environments, causing a fatal
"panic: get_pv_entry: cannot get a pv_entry_t". The same panic might
still occur due to temporary shortage of free physical memory
(cf. PR i386/2431).
This eliminates a lot of #ifdef SMP type code. Things like _curproc reside
in a data page that is unique on each cpu, eliminating the expensive macros
like: #define curproc (SMPcurproc[cpunumber()])
There are some unresolved bootstrap and address space sharing issues at
present, but Steve is waiting on this for other work. There is still some
strictly temporary code present that isn't exactly pretty.
This is part of a larger change that has run into some bumps, this part is
standalone so it should be safe. The temporary code goes away when the
full idle cpu support is finished.
Reviewed by: fsmp, dyson
cost since it is only done in cpu_switch(), not for every exception.
The extra state is kept in the pcb, and handled much like the npx state,
with similar deficiencies (the state is not preserved across signal
handlers, and error handling loses state).
