Exapnd comments on System V IPC labeling methods, which could use improved
consistency with respect to other object types.
Obtained from: TrustedBSD Project
the ifnet itself. The stack copy has been made while holding the mutex
protecting ifnet labels, so copying from the ifnet copy could result in
an inconsistent version being copied out.
Reported by: Todd.Miller@sparta.com
Obtained from: TrustedBSD Project
MFC after: 3 weeks
- Move linux_nanosleep() from src/sys/amd64/linux32/linux32_machdep.c to
src/sys/compat/linux/linux_time.c.
- Validate timespec ranges before use as Linux kernel does.
- Fix l_timespec structure.
- Clean up style(9) nits.
Add rudimentary IPC_INFO/MSG_INFO command support for linux_msgctl()
to pacify Linux ipcs(1). While I am here, add more bound checks
for linux_msgsnd() and linux_msgrcv().
copyin()/copyout() for message type is separated from msgsnd()/msgrcv() and
it is done from its wrapper functions to support 32-bit emulations. After I
implemented this, I have briefly referenced NetBSD and Darwin. NetBSD passes
copyin()/copyout() function pointers from wrappers. Darwin passes size of
message type as an argument, which is actually similar to my first
implementation (P4 109706). We may revisit these implementations later.
would be able to work with aac(4).
This approach is used by some other drivers as well. However, we
need a more generic way to do this in order to avoid having to
special case headers in individual drivers for each platform.
Obtained from: Adaptec (version b11518)
Approved by: scottl
been handled instead of when at least one descriptor was just handled.
For bge, it is normal to get a txeof when only a small fraction of the
queued tx descriptors have been handled, so the bug broke the watchdog
in a usual case.
- moved the synchronizing bus read to after the bus write for the first
interrupt ack so that it actually synchronizes everything necessary.
We were acking not only the status update that triggered the interrupt
together with any status updates that occurred before we got around
to the bus write for the ack, but also any status updates that occur
after we do the bus write but before the write reaches the device.
The corresponding race for the second interrupt ack resulted in
sometimes returning from the interrupt handler with acked but
unserviced interrupt events. Such events then remain unserviced
until further events cause another interrupt or the watchdog times
out.
The race was often lost on my 5705, apparently since my 5705 has broken
event coalescing which causes a status update for almost every packet,
so another status update is quite likely to occur while the interrupt
handler is running. Watchdog timeouts weren't very noticeable,
apparently because bge_txeof() has one of the usual bugs resetting the
watchdog.
- don't disable device interrupts while bge_intr() is running. Doing this
just had the side effects of:
- entering a device mode in which different coalescing parameters apply.
Different coalescing parameters can be used to either inhibit or
enhance the chance of getting another status update while in the
interrupt handler. This feature is useless with the current
organization of the interrupt handler but might be useful with a
taskqueue handler.
- giving a race for ack+reenable/return. This cannot be handled
by simply rearranging the order of bus accesses like the race for
ack+keepenable/entry. It is necessary to sync the ack and then
check for new events.
- taking longer, especially with the extra code to avoid the race on
ack+reenable/return.
Reviewed by: ru, gleb, scottl
vnode v_flag. For cluster buffers this would result in dereferencing NULL
b_vp. To prevent the panic, cache relevant vnode flag before calling
bstrategy.
Reported by: Peter Holm, kris
Tested by: Peter Holm
Reviewed by: tegge
Pointy hat to: kib
This is consistent with kern.module_path sysctl and also compensates
for the unconventional syntax of asf(8) where the last of multiple
arguments is the output file, which prevents us from using the
traditional Unix syntax "foo file ..." to specify multiple module
dirs.
Submitted by: emaste
MFC after: 1 week
running thread's id on each cpu. This allow us to add in-kernel adaptive
spin for user level mutex. While spinning in user space is possible,
without correct thread running state exported from kernel, it hardly
can be implemented efficiently without wasting cpu cycles, however
exporting thread running state unlikely will be implemented soon as
it has to design and stablize interfaces. This implementation is
transparent to user space, it can be disabled dynamically. With this
change, mutex ping-pong program's performance is improved massively on
SMP machine. performance of mysql super-smack select benchmark is increased
about 7% on Intel dual dual-core2 Xeon machine, it indicates on systems
which have bunch of cpus and system-call overhead is low (athlon64, opteron,
and core-2 are known to be fast), the adaptive spin does help performance.
Added sysctls:
kern.threads.umtx_dflt_spins
if the sysctl value is non-zero, a zero umutex.m_spincount will
cause the sysctl value to be used a spin cycle count.
kern.threads.umtx_max_spins
the sysctl sets upper limit of spin cycle count.
Tested on: Athlon64 X2 3800+, Dual Xeon 5130
re_watchdog() in order to avoid races accessing if_timer.
- Use bus_get_dma_tag() so re(4) works on platforms requiring it.
- Remove invalid BUS_DMA_ALLOCNOW when creating the parent DMA tag
and the tags that are used for static memory allocations.
- Don't bother to set if_mtu to ETHERMTU, ether_ifattach() does that.
- Remove an unused variable in re_intr().
watchdog timer in dc_txeof() in case there are still unhandled
descriptors as dc_poll() invokes dc_poll() unconditionally.
Otherwise this would result in the watchdog timer constantly being
being reloaded and thus circumvent that the watchdog ever fires in
the DEVICE_POLLING case.
Pointed out by: bde
pmap.c, and is potentially the cause of hangs reported on machines with a
small amount of memory. On machines with sufficient RAM, and without a lot
of processes running, this situation would probably never occur.
Testing is still incomplete, but it is obviously wrong so remove the
offending code now.
The issue of what to do when both the primary and secondary hash overflow
is still open.
Reported by: Dan Kresja at windriver dot com, via alc
