obtaining and releasing shared and exclusive locks. The algorithms for
manipulating the lock cookie are very similar to that rwlocks. This patch
also adds support for exclusive locks using the same algorithm as mutexes.
A new sx_init_flags() function has been added so that optional flags can be
specified to alter a given locks behavior. The flags include SX_DUPOK,
SX_NOWITNESS, SX_NOPROFILE, and SX_QUITE which are all identical in nature
to the similar flags for mutexes.
Adaptive spinning on select locks may be enabled by enabling the
ADAPTIVE_SX kernel option. Only locks initialized with the SX_ADAPTIVESPIN
flag via sx_init_flags() will adaptively spin.
The common cases for sx_slock(), sx_sunlock(), sx_xlock(), and sx_xunlock()
are now performed inline in non-debug kernels. As a result, <sys/sx.h> now
requires <sys/lock.h> to be included prior to <sys/sx.h>.
The new kernel option SX_NOINLINE can be used to disable the aforementioned
inlining in non-debug kernels.
The size of struct sx has changed, so the kernel ABI is probably greatly
disturbed.
MFC after: 1 month
Submitted by: attilio
Tested by: kris, pjd
watchdog might hide the succesful arming of an earlier one. Accept that on
failing to arm any watchdog (because of non-supported timeouts) EOPNOTSUPP is
returned instead of the more appropriate EINVAL.
MFC after: 3 days
code.
# There is some question about whether this code is even relevant any
# longer (it dates back to prehistoric times, i.e. present in r1.1),
# especially on amd64.
Reviewed by: jhb
cpufreq_pre_change is called before the change, giving each driver a chance
to revoke the change. cpufreq_post_change provides the results of the
change (success or failure). cpufreq_levels_changed gives the unit number
of the cpufreq device whose number of available levels has changed. Hook
in all the drivers I could find that needed it.
* TSC: update TSC frequency value. When the available levels change, take the
highest possible level and notify the timecounter set_cputicker() of that
freq. This gets rid of the "calcru: runtime went backwards" messages.
* identcpu: updates the sysctl hw.clockrate value
* Profiling: if profiling is active when the clock changes, let the user
know the results may be inaccurate.
Reviewed by: bde, phk
MFC after: 1 month
temporary mapping created by locore so that the lowest two to four
megabytes can become a permanent identity mapping. This implementation
avoids any use of a large page mapping.
handles when activating a resource via bus_activate_resource() rather than
doing some of the work in bus_alloc_resource() and some of it in
bus_activate_resource().
One note is that when using isa_alloc_resourcev() on PC-98, drivers now
need to just use bus_release_resource() without explicitly calling
bus_deactivate_resource() first. nyan@ has already fixed all of the PC-98
drivers.
address ranges used by local and I/O APICs in the system. Some systems
also reserve these ranges as system resources via either PnPBIOS or
ACPI, so this device currently attaches after acpi0 and legacy0 so that
the system resources are given precedence.
addresses corresponding to system RAM. On amd64 ram0 uses the SMAP
and claims all the type 1 SMAP regions. On i386 ram0 uses the
dump_avail[] array. Note that on i386 we have to ignore regions above
4G in PAE kernels since bus resources use longs.
boot. Then, just switch to the kernel pmap when suspending instead of
allocating/freeing our own mapping every time. This should solve a panic
of pmap_remove() being called with interrupts disabled. Thanks to Alan
Cox for developing this patch.
Note: this means that ACPI requires super page (PG_PS) support in the CPU.
This has been present since the Pentium and first documented in the
Pentium Pro. However, it may need to be revisited later.
Submitted by: alc
MFC after: 1 month
GETATTRs being generated - one from lookup()/namei() and the other
from nfs_open() (for cto consistency). This change eliminates the
GETATTR in nfs_open() if an otw GETATTR was done from the namei()
path. Instead of extending the vop interface, we timestamp each attr
load, and use this to detect whether a GETATTR was done from namei()
for this syscall. Introduces a thread-local variable that counts the
syscalls made by the thread and uses <pid, tid, thread syscalls> as
the attrload timestamp. Thanks to jhb@ and peter@ for a discussion on
thread state that could be used as the timestamp with minimal overhead.
For example, during a buildworld more than half of the calls do not
generate an IPI because the only TLB entry invalidated is on the calling
processor. This revision pushes down the acquisition and release of
smp_ipi_mtx into smp_tlb_shootdown() and smp_targeted_tlb_shootdown() and
instead uses sched_pin() and sched_unpin() in pmap_invalidate_*() so that
thread migration doesn't lead to a missed TLB invalidation.
Reviewed by: jhb
MFC after: 3 weeks
RTC state, then it may clobber the RTC index register, so the index
register must be restored before using it to restore control registers
in rtc_restore().
The following problems remain:
- rtc_restore() is only called if pmtimer is configured. Buggy
suspend/resumes are more likely to clobber the index register than
a control register, so pmtimer is more needed than it used to be.
- pmtimer doesn't exist for amd64.
- Restoring of the RTC state may race with rtcintr(). If an RTC
interrupt is handled before the state is restored, then rtcin(RTC_INTR)
in rtcintr() may read from the wrong register, so rtcintr() may spin
forever. This may be mitigated by the most common state clobbering
being to turn off RTC interrupts.
Linux does not check file descriptor when MAP_ANONYMOUS is set.
This should fix recent LTP test regressions.
Reported by: Scot Hetzel (swhetzel at gmail dot com)
netchild
- Dont "return" in linux_clone() after we forked the new process in a case
of problems.
- Move the copyout of p2->p_pid outside the emul_lock coverage in
linux_clone().
- Cache the em->pdeath_signal in a local variable and move the copyout
out of the emul_lock coverage.
- Move the free() out of the emul_shared_lock coverage in a preparation
to switch emul_lock to non-sleepable lock (mutex).
Submitted by: rdivacky
