Marius Strobl 4cf9e21ed8 - Give PIL_PREEMPT the lowest priority just above low/stray interrupts. ... The reason for this is that the SPARC v9 architecture allows nested interrupts of higher priority/level than that of the current interrupt to occur (and we can't just entirely bypass this model, also, at least for tick interrupts, this also wouldn't be wise). However, when a preemption interrupt interrupts another interrupt of lower priority, f.e. PIL_ITHREAD, and that one in turn is nested by a third interrupt, f.e. PIL_TICK, with SCHED_ULE the execution of interrupts higher than PIL_PREEMPT may be migrated to another CPU. In particular, tl1_ret(), which is responsible for restoring the state of the CPU prior to entry to the interrupt based on the (also migrated) trap frame, then is run on a CPU which actually didn't receive the interrupt in question, causing an inappropriate processor interrupt level to be "restored". In turn, this causes interrupts of the first level, i.e. PIL_ITHREAD in the above scenario, to be blocked on the target of the migration until the correct PIL happens to be restored again on that CPU again. Making PIL_PREEMPT the lowest real priority, this effectively prevents this scenario from happening, as preemption interrupts no longer can interrupt any other interrupt besides stray ones (which is no issue). Thanks to attilio@ and especially mav@ for helping me to understand this problem at the 201208DevSummit. - Give PIL_STOP (which is also used for IPI_STOP_HARD, given that there's no real equivalent to NMIs on SPARC v9) the highest possible priority just below the hardwired PIL_TICK, so it has a chance to interrupt more things. MFC after: 1 week		2012-10-20 12:07:48 +00:00
..
_align.h
_bus.h
_inttypes.h
_limits.h
_stdint.h	Make the wchar_t type machine dependent.	2012-06-24 04:15:58 +00:00
_types.h	Make the wchar_t type machine dependent.	2012-06-24 04:15:58 +00:00
asi.h
asm.h
asmacros.h	- Use atomic operations rather than sched_lock for safely assigning pm_active	2011-10-06 11:01:31 +00:00
atomic.h	Add an unified macro to deny ability from the compiler to reorder	2012-10-09 14:32:30 +00:00
bus_common.h
bus_dma.h	- Change contigmalloc() to use the vm_paddr_t type instead of an unsigned	2012-03-01 19:58:34 +00:00
bus_private.h	Make sparc64 compatible with NEW_PCIB and enable it:	2011-10-02 23:22:38 +00:00
bus.h	Make sparc64 compatible with NEW_PCIB and enable it:	2011-10-02 23:22:38 +00:00
cache.h
ccr.h
clock.h	Now that we have a working OF_printf() since r230631 and a OF_panic()	2012-01-27 23:21:54 +00:00
cmt.h
cpu.h	Mark cpu_{halt,reset}() as __dead2 as appropriate.	2012-01-27 22:04:43 +00:00
cpufunc.h
db_machdep.h
dcr.h
elf.h	Reserve AT_TIMEKEEP auxv entry for providing usermode the pointer to	2012-06-22 06:38:31 +00:00
endian.h	Add casts to __uint16_t to the __bswap16() macros on all arches which	2012-03-09 20:34:31 +00:00
exec.h
fireplane.h
float.h	Add C11 macros describing subnormal numbers to float.h.	2012-01-23 06:36:41 +00:00
floatingpoint.h
fp.h
frame.h
fsr.h	Add a global MD macro for the VIS block size instead of duplicating	2012-08-31 11:15:01 +00:00
gdb_machdep.h
idprom.h
ieee.h
ieeefp.h	People porting FreeBSD to new architectures ought not have to	2011-10-21 06:41:46 +00:00
in_cksum.h	MFp4 bz_ipv6_fast:	2012-05-24 22:00:48 +00:00
instr.h
intr_machdep.h	- Give PIL_PREEMPT the lowest priority just above low/stray interrupts.	2012-10-20 12:07:48 +00:00
iommureg.h
iommuvar.h
jbus.h
kdb.h
kerneldump.h
ktr.h
limits.h
lsu.h
mcntl.h
md_var.h	For sparc64 also adjust the geometry of da(4) driven disks to not overflow	2011-11-27 15:43:40 +00:00
memdev.h
metadata.h
nexusvar.h
ofw_machdep.h	- Now that we have a working OF_printf() since r230631, use it for	2012-01-27 22:35:53 +00:00
ofw_mem.h
ofw_nexus.h
param.h	Merge from r224217:	2011-07-20 18:51:18 +00:00
pcb.h	Add a convenience macro for the returns_twice attribute, and apply it to	2012-04-29 11:04:31 +00:00
pcpu.h	Define curthread as an inline function that loads the thread pointer	2011-11-15 20:17:18 +00:00
pmap.h	Merge r236494 from x86:	2012-08-05 22:03:13 +00:00
pmc_mdep.h
proc.h	Remove unused define.	2011-10-07 16:09:44 +00:00
profile.h
pstate.h
ptrace.h
reg.h
reloc.h
resource.h
runq.h
sc_machdep.h
setjmp.h
sf_buf.h
sigframe.h
signal.h
smp.h	- Unlike cache invalidation and TLB demapping IPIs, reading registers from	2012-08-29 16:56:50 +00:00
stack.h
stdarg.h
sysarch.h
tick.h
tlb.h
trap.h
tsb.h
tstate.h
tte.h
ucontext.h
upa.h
utrap.h
varargs.h
vdso.h	Implement mechanism to export some kernel timekeeping data to	2012-06-22 07:06:40 +00:00
ver.h
vm.h
vmparam.h	Prevent indent(1) from reformatting this comment, as it contains	2012-09-07 08:18:06 +00:00
watch.h
wstate.h