turnstiles to implement blocking isntead of implementing a thread queue
directly. These turnstiles are somewhat similar to those used in Solaris 7
as described in Solaris Internals but are also different.
Turnstiles do not come out of a fixed-sized pool. Rather, each thread is
assigned a turnstile when it is created that it frees when it is destroyed.
When a thread blocks on a lock, it donates its turnstile to that lock to
serve as queue of blocked threads. The queue associated with a given lock
is found by a lookup in a simple hash table. The turnstile itself is
protected by a lock associated with its entry in the hash table. This
means that sched_lock is no longer needed to contest on a mutex. Instead,
sched_lock is only used when manipulating run queues or thread priorities.
Turnstiles also implement priority propagation inherently.
Currently turnstiles only support mutexes. Eventually, however, turnstiles
may grow two queue's to support a non-sleepable reader/writer lock
implementation. For more details, see the comments in sys/turnstile.h and
kern/subr_turnstile.c.
The two primary advantages from the turnstile code include: 1) the size
of struct mutex shrinks by four pointers as it no longer stores the
thread queue linkages directly, and 2) less contention on sched_lock in
SMP systems including the ability for multiple CPUs to contend on different
locks simultaneously (not that this last detail is necessarily that much of
a big win). Note that 1) means that this commit is a kernel ABI breaker,
so don't mix old modules with a new kernel and vice versa.
Tested on: i386 SMP, sparc64 SMP, alpha SMP
- Fail in agp_alloc_gatt if the aperture size is 0 instead of panicing in
contigmalloc.
Reported by: Bjoern Fischer <bfischer@Techfak.Uni-Bielefeld.DE>
Reviewed by: jhb
MFC after: 1 week
interrupt such as IRQ 22 or 19. However, the ACPI BIOS still routes
interrupts from some PCI devices to the same intpin calling the pin
IRQ 22. Thus, ACPI expects to address a single interrupt source via two
different names. To work around this, if the SCI is remapped to a non-ISA
interrupt (i.e., greater than 15), then we use
acpi_OverrideInterruptLevel() function to tell ACPI to use IRQ 22 or 19
rather than IRQ 9 for the SCI.
Previously we would change IRQ 22 or 19's name to IRQ 9 when we encountered
such an Interrupt Source Override entry in the MADT which routed the SCI
properly but left PCI devices mapped to IRQ 22 or 19 w/o a routable
interrupt.
Tested by: sos
This ensures that uart gets a higher console priority than syscons when
a serial console is being used. Testing against the "console" environment
variable doesn't make sense since we only have one loader console driver.
should now only have HTT CPUs if they have explicitly asked for them
either by enabling HyperThreading in the BIOS or by using the
MPTABLE_FORCE_HTT kernel option.
should only be used if they are enabled in the BIOS. Now that we support
enumerating CPUs using the ACPI MADT, any HTT machine using ACPI should
respect the BIOS setting. For HTT machines with ACPI disabled in the
kernel, the MPTABLE_FORCE_HTT kernel option can be used to try to probe HTT
CPUs like have done in the past for the MP Table case. This option should
only be enabled if HTT is enabled in the BIOS.
that we currently do not keep track of whether the thread has
actually used the high FP registers before. If not, we should
not save them in the context which automaticly means that we
also would not restore them from the context. For now, do it
unconditionally so that we can reach functional completeness.
functions switched to using {g|s}et_mcontext(). The problem is that
sigreturn(), being a syscall, can be given an async. context (i.e.
one corresponding to an interrupt or trap). When this happens, we
try to return to user mode via epc_syscall_return with a trapframe
that can only be used to return to user mode via exception_restore.
To fix this, we check the frame's flags immediately prior to
epc_syscall_return and branch to exception_restore for non-syscall
frames. Modify the assertion in set_mcontext() to check that if
there's a mismatch, it's because of sigreturn().
ktr_resize_pool(); this eliminates a potential livelock.
Return ENOSPC only if we encountered an out-of-memory condition when
trying to increase the pool size.
Reviewed by: jhb, bde (style)
cache after a data access error we must discard all cache lines. When
disabled existing cache lines are not invalidated by stores to memory, so
we risk reading stale data that was cached before the data access error if
we don't flush them. This is especially fatal when the memory involved
is the active part of the kernel or user stack. For good measure we also
flush the instruction cache.
This fixes random crashes when the X server probes the PCI bus through
/dev/pci.
commit broke the world because it depended on namespace pollution that
was only in my version of <machine/bootinfo.h>. The include was removed
in rev.1.63 after the last reference to it went away in rev.1.61.
dsp_open: rearrange to only hold one lock at a time
dsp_close: ditto
mixer_hwvol_init: delete locking, the only consumer seems to
be the ess driver and it only call it a creation time, I
think the device will be stable across the sleepable malloc.
cmi interrupt routine: Release locks while caller chn_intr,
either this or do what emu10k1 does which is have no locks
at in the interrupt handler.
Submitted by: mat@cnd.mcgill.ca
sorting strings with common prefixes by noting
when all the strings land in just one bin.
Testing shows significant speedups (on the order of
30%) on strings with common prefixes and no slowdowns on any
of my test cases.
Submitted by: Markus Bjartveit Kruger <markusk@pvv.ntnu.no>
PR: 58860
Approved by: gordon (mentor)
