Specifically, we used to enable the source after locking sched_lock
and just before we had already decided to do a context switch.
This meant that an ithread could never process more than one interrupt
per context switch. Enabling earlier in the loop before sched_lock is
acquired allows an ithread to handle multiple interrupts per context
switch if interrupts fire very rapidly. For the case of heavy interrupt
load this can reduce the number of context switches (and thus overhead)
as well as reduce interrupt latency.
- Now that we can handle multiple interrupts per context switch, add simple
interrupt storm protection to threaded interrupts. If X number of
consecutive interrupts are triggered before the itherad voluntarily
yields to another thread, then the interrupt thread will sleep with the
associated interrupt source disabled (masked) for 1/10th of a second.
The default value of X is 500, but it can be tweaked via the tunable/
sysctl hw.intr_storm_threshold. If an interrupt storm is detected, then
a message is output to the kernel console on the first occurrence per
interrupt thread. Interrupt storm protection can be disabled completely
by setting this value to 0. There is no scientific reasoning for the
1/10th of a second or 500 interrupts values, so they may require tweaking
at some point in the future.
Tested by: rwatson (an earlier version w/o the storm protection)
Tested by: mux (reportedly made a machine with two PCI interrupts
storming usable rather than hard locked)
Reviewed by: imp
different BIOSs use the same exact settings to mean two very different and
incompatible things for the SCI. Thus, if the SCI is remapped to a PCI
interrupt, we now trust the trigger/polarity that the MADT provides by
default. However, the SCI can be forced to level/lo as 1.10 did by setting
the tunable "hw.acpi.force_sci_lo" to a non-zero value from the loader.
Thus, if rev 1.10 caused an interrupt storm, it should nwo fix your
machine. If rev 1.10 fixed an interrupt storm on your machine, you
probably need to set the aforementioned tunable in /boot/loader.conf to
prevent the interrupt storm.
The more general problem of getting the SCI's trigger/polarity programmed
"correctly" (for some value of correctly meaning several workarounds for
broken BIOSs and inconsistent "implementations" of the ACPI standard) is
going to require more work, but this band-aid should improve the current
situation somewhat.
Requested by: njl
acpi_toshiba(4) video switching support,
getvfsent(3) removed,
sx driver added,
pci(4) bus resource and power management updated,
per-interface polling(4) support,
ata(4) early support for Promise SX4/SX4000,
dump(8) and restore(8) -P option,
make(1) .warning directive,
ACPI-CA 20040402 import, and
CVS 1.11.15 import.
Update release note:
Use &man.twa.4;.
uiomove(9) is not properly locked. So, return to NEEDGIANT
mode. Later, when uiomove is finely locked, I'll revisit.
While I'm here, provide some temporary debugging output to
help catch blocking startups.
unconditionally initialize the mbuf header even if cluster allocation
failed, which could result in a NULL pointer dereference in low-memory
conditions.
PR: kern/65548
Submitted by: Stephan Uphoff <ups@tree.com>
the TAILQ_FOREACH() form.
Comment the need to store the same info (mac address for ethernet-type
devices) in two different places.
No functional changes. Even the compiler output should be unmodified
by this change.
o mention that the acctfile has to exist for accton to work [1]
o add reference to acct.5
PR: 65071 [1] (slightly modified)
Submitted by: Marc Silver <marcs@draenor.org>
X-MFC after: re approval
of an interface. No functional change.
On passing, comment an useless invocation of TAILQ_INIT(&ifp->if_addrhead)
which could probably be removed in the interest of clarity.
of an interface. No functional change.
On passing, comment a likely bug in net/rtsock.c:sysctl_ifmalist()
which, if confirmed, would deserve to be fixed and MFC'ed
Earlier versions of FreeBSD don't support ACLs.
Note that the ACL support code in archive_entry is standalone code and
unaffected by this. (In particular, it should be possible to
manipulate archives containing ACLs even if the ACLs cannot be
restored on the current system.)
ntoskrnl_unlocl_dpc().
- hal_raise_irql(), hal_lower_irql() and hal_irql() didn't work right
on SMP (priority inheritance makes things... interesting). For now,
use only two states: DISPATCH_LEVEL (PI_REALTIME) and PASSIVE_LEVEL
(everything else). Tested on a dual PIII box.
- Use ndis_thsuspend() in ndis_sleep() instead of tsleep(). (I added
ndis_thsuspend() and ndis_thresume() to replace kthread_suspend()
and kthread_resume(); the former will preserve a thread's priority
when it wakes up, the latter will not.)
- Change use of tsleep() in ndis_stop_thread() to prevent priority
change on wakeup.
table for the hardlink cache. This dramatically improves
performance when archiving millions of hardlinked files.
While I'm here, clean up some style bugs (per Bruce Evans)
and clarify some comments.
if the link-level address has been initialized already.
The majority of modern drivers never does this and works fine, which
makes me think that the check is totally unnecessary and a residue
of cut&paste from other drivers.
This change is done to simplify locking because now almost none of the
drivers uses this field. The exceptions are "ct" "ctau" and "cx"
where i am not sure if i can remove that part.
initdiskless. The output of several commands and if available the
contents of /entropy are feed into /dev/random to kickstart the PRNG.
/etc/rc.d/initrandom is left alone to maintain the previous behavior as
much as possiable.
Further work in this area is probably needed.
Discussed with: markm
