for structures with timers in them. It might be that a timer might fire
even when the associated structure has already been free'd. Having type-
stable storage in this case is beneficial for graceful failure handling and
debugging.
Discussed with: bosko, tegge, rwatson
called "rtentry".
This saves a considerable amount of kernel memory. R_Zmalloc previously
used 256 byte blocks (plus kmalloc overhead) whereas UMA only needs 132
bytes.
Idea from: OpenBSD
incomplete in that the PRT routing was not aware of link programming.
Fix this by doing all routing through the link devices. The new algorithm
for setting up links is:
1. Read _CRS to get current setting. If invalid (not in _PRS), then set
to 0.
2. Attempt to call _DIS on the link. If successful, mark the link as not
routed. Otherwise, assume it still is.
Then when a routing request occurs:
3. Update weights for all IRQs
4. Attempt to route the initial IRQ if valid
5. If that fails, walk through the sorted list, attempting to route IRQs.
6. Configure the trigger/polarity based on _PRS.
Other changes:
* Add acpi_pci_find_prt() to look up the PRT entry for a given device and
acpi_pci_link_route() to select/route the best IRQ for it.
* Remove duplicated code in acpi_pcib_route_interrupt() that picked the
first IRQ from _PRS.
* Remove unneeded arguments from acpi_pcib_resume() and friends.
* Ignore _STA on link devices but report if it seems strange.
* Add a prt_source handle to the PRT structure since the ACPI struct
ACPI_PCI_ROUTING_TABLE uses a fixed-size entry for it. We'll need to
dynamically size this object if we want to use it the same way ACPI-CA
does. Null-terminate the source.
Tested by: Luo Hong <luohong99_at_mails.tsinghua.edu.cn>,
Jeffrey Katcher <jmkatcher_at_yahoo.com>
Info from: jhb, Len Brown (Intel)
and bio_inbed fields to 0. Without this change we can end up with
I/O leakage in some rare situations.
I tested this change by putting failure probability mechanism simlar
to this used in NOP class into g_clone_bio(9) function, so it was
able to return NULL with the given probability.
Discussed with: phk
we update the registers. That way we don't have any dirty registers to
worry about and also know that bsp=bspstore, which makes updating the
RSE related registers predictable.
This is not the end of it. We need more validity checks, but for now
this allows us to complete the gdb testsuite without crashing the
kernel.
if_start routines cannot currently be entered without Giant. When
the kernel is running with debug.mpsafenet != 0, this will defer
if_start execution to a task queue thread holding Giant, which may
introduce additional latency, but avoid incorrect execution.
Suggested by: dfr
full, avoiding the cost of mutex operations if it is. We re-test
once the mutex is acquired to make sure it's still true before doing
the -modify-write part of the read-modify-write. Note that due to
the maximum fifo depth being pretty deep, this is unlikely to improve
harvesting performance yet.
Approved by: markm
to allow dumping per-thread machine specific notes. On ia64 we use this
function to flush the dirty registers onto the backingstore before we
write out the PRSTATUS notes.
Tested on: alpha, amd64, i386, ia64 & sparc64
Not tested on: arm, powerpc
a standard configuration similar to [NO_]ADAPTIVE_MUTEXES. This
feature causes Giant to be included in the set of mutexes adaptively
spun on. It appears to have a positive effect on performance on SMP
across several workloads, including measurements of a 16% improvement
on buildworld, and 30%+ improvement for MySQL using the supersmack
benchmark with Giant over the network stack; a 6% improvement without
Giant on the network stack (as a result of less giant contention).
we may sleep when doing so; check that we didn't race with another thread
allocating storage for the vnode after allocation is made to a local
pointer, and only update the vnode pointer if it's still NULL. Otherwise,
accept that another thread got there first, and release the local storage.
Discussed with: jmg
Implement the protection check required by the pmap_extract_and_hold()
specification.
Remove the acquisition and release of Giant from pmap_extract_and_hold() and
pmap_protect().
Many thanks to Ken Smith for resolving a sparc64-specific initialization
problem in my original patch.
Tested by: kensmith@
bio_driver1 (as all the rest).
This introduced a small memory leak, but it wasn't really critical,
because maximum memory for g_stripe_zone is always set, so after few
requests gstripe was working in "economic" mode.
are resevered, they can be written with anything, but they always read
as zero, we should simulate it in set_regs() as we are reading/writting
real hardware %rflags register.
contributed to the transferable load count. This prevents any potential
problems with sched_pin() being used around calls to setrunqueue().
- Change the sched_add() load balancing algorithm to try to migrate on
wakeup. This attempts to place threads that communicate with each other
on the same CPU.
- Don't clear the idle counts in kseq_transfer(), let the cpus do that when
they call sched_add() from kseq_assign().
- Correct a few out of date comments.
- Make sure the ke_cpu field is correct when we preempt.
- Call kseq_assign() from sched_clock() to catch any assignments that were
done without IPI. Presently all assignments are done with an IPI, but I'm
trying a patch that limits that.
- Don't migrate a thread if it is still runnable in sched_add(). Previously,
this could only happen for KSE threads, but due to changes to
sched_switch() all threads went through this path.
- Remove some code that was added with preemption but is not necessary.
