Because of this we were not getting further interrupts for link state
changes, thus never went into iface UP state and thus could not transmit.
The only way out of this was an incoming packet generating an rx interrupt
and making us call into bge_link_upd.
Up to rev. 1.101, in bge_start_locked, we only returned instantly
if there was 'no link AND nothing queued for tx'. So with a packet queued
for tx, we hit the register scrubbing at the end of bge_start_locked
and were out fine. We simply lost a packet or two but got the interrupts
need to get into UP state.
With rev. 1.102 this was turned into 'if there is no link OR there is
nothing to send' (correct behaviour) and as long as there is no link
we never hit the register scrubbing and consequently never got the link UP.
What we do now is force an interrupt at the end of bge_ifmedia_upd_locked
so we will call bge_link_upd, clear the link state attention and get
further interrupts.
This helps to get the iface UP on an idle network or at least to get
it UP faster not depending on an rx intr anymore.
In case you could not get a DHCP lease or it took very long,
it was because of this.
It is unknown which chips are affected by this. ASIC rev. 0x2003 was the
most popular trouble candidate.
At least the fiber cards should have been working fine.
Which register to scrub is currently under discussion. The comitted
solution was tested and found to work for a lot of setups. It might
not help with MSI.
The reason why we end up in such a situation is entirely unknown.
PR: kern/111804
Tested by: phk, scottl at Y!
MFC after: 14 days
was changed in rev. 1.161 of tcp_var.h. All option now test for sufficient
space in TCP header before getting added.
Reported by: Mark Atkinson <atkin901-at-yahoo.com>
Tested by: Mark Atkinson <atkin901-at-yahoo.com>
MFC after: 1 week
bit in order to allow per-bit checks on the options flag, in particular
in the consumers code [1]
- Re-enable the check against TDP_DEADLKTREAT as the anti-waiters
starvation patch allows exclusive waiters to override new shared
requests.
[1] Requested by: pjd, jeff
buffer kernel descriptors, which is used to allow the buffer
currently in the BPF "store" position to be assigned to userspace
when it fills, even if userspace hasn't acknowledged the buffer
in the "hold" position yet. To implement this, notify the buffer
model when a buffer becomes full, and check that the store buffer
is writable, not just for it being full, before trying to append
new packet data. Shared memory buffers will be assigned to
userspace at most once per fill, be it in the store or in the
hold position.
This removes the restriction that at most one shared memory can
by owned by userspace, reducing the chances that userspace will
need to call select() after acknowledging one buffer in order to
wait for the next buffer when under high load. This more fully
realizes the goal of zero system calls in order to process a
high-speed packet stream from BPF.
Update bpf.4 to reflect that both buffers may be owned by userspace
at once; caution against assuming this.
state transitioning flags and of msleep(9) callings.
Use, instead, an algorithm very similar to what sx(9) and rwlock(9)
alredy do and direct accesses to the sleepqueue(9) primitive.
In order to avoid writer starvation a mechanism very similar to what
rwlock(9) uses now is implemented, with the correspective per-thread
shared lockmgrs counter.
This patch also adds 2 new functions to lockmgr KPI: lockmgr_rw() and
lockmgr_args_rw(). These two are like the 2 "normal" versions, but they
both accept a rwlock as interlock. In order to realize this, the general
lockmgr manager function "__lockmgr_args()" has been implemented through
the generic lock layer. It supports all the blocking primitives, but
currently only these 2 mappers live.
The patch drops the support for WITNESS atm, but it will be probabilly
added soon. Also, there is a little race in the draining code which is
also present in the current CVS stock implementation: if some sharers,
once they wakeup, are in the runqueue they can contend the lock with
the exclusive drainer. This is hard to be fixed but the now committed
code mitigate this issue a lot better than the (past) CVS version.
In addition assertive KA_HELD and KA_UNHELD have been made mute
assertions because they are dangerous and they will be nomore supported
soon.
In order to avoid namespace pollution, stack.h is splitted into two
parts: one which includes only the "struct stack" definition (_stack.h)
and one defining the KPI. In this way, newly added _lockmgr.h can
just include _stack.h.
Kernel ABI results heavilly changed by this commit (the now committed
version of "struct lock" is a lot smaller than the previous one) and
KPI results broken by lockmgr_rw() / lockmgr_args_rw() introduction,
so manpages and __FreeBSD_version will be updated accordingly.
Tested by: kris, pho, jeff, danger
Reviewed by: jeff
Sponsored by: Google, Summer of Code program 2007
contigmalloc(9) as a last resort to steal pages from an inactive,
partially-used superpage reservation.
Rename vm_reserv_reclaim() to vm_reserv_reclaim_inactive() and
refactor it so that a separate subroutine is responsible for breaking
the selected reservation. This subroutine is also used by
vm_reserv_reclaim_contig().
allows all the INTR_FILTER #ifdef's to be removed from the MD interrupt
code.
- Rename the intr_event 'eoi', 'disable', and 'enable' hooks to
'post_filter', 'pre_ithread', and 'post_ithread' to be less x86-centric.
Also, add a comment describe what the MI code expects them to do.
- On amd64, i386, and powerpc this is effectively a NOP.
- On arm, don't bother masking the interrupt unless the ithread is
scheduled in the non-INTR_FILTER case to match what INTR_FILTER did.
Also, don't bother unmasking the interrupt in the post_filter case if
we never masked it. The INTR_FILTER case had been doing this by having
arm_unmask_irq for the post_filter (formerly 'eoi') hook.
- On ia64, stray interrupts are now masked for the non-INTR_FILTER case.
They were already masked in the INTR_FILTER case.
- On sparc64, use the a NULL pre_ithread hook and use intr_enable_eoi() for
both the 'post_filter' and 'post_ithread' hooks to match what the
non-INTR_FILTER code did.
- On sun4v, retire the ithread wrapper hack by using an appropriate
'post_ithread' hook instead (it's what 'post_ithread'/'enable' was
designed to do even in 5.x).
Glanced at by: piso
Reviewed by: marius
Requested by: marius [1], [5]
Tested on: amd64, i386, arm, sparc64
part of detecting the media. Explicitly ensure that we don't send it to
bpf(4) as bpf(4) isn't setup yet. This worked by accident before the bpf
interface stuff was reworked to avoid other races (bpf_peers_present, etc.)
but now it needs an explicit check to avoid a panic.
MFC after: 3 days
PR: kern/120915
UMA_SLAB_KERNEL for consistency with its sibling UMA_SLAB_KMEM.
(UMA_SLAB_KMAP met its original demise in revision 1.30 of
vm/uma_core.c.) UMA_SLAB_KERNEL is now required by the jumbo frame
allocators. Without it, UMA cannot correctly return pages from the
jumbo frame zones to the VM system because it resets the pages' object
field to NULL instead of the kernel object. In more detail, the jumbo
frame zones are created with the option UMA_ZONE_REFCNT. This causes
UMA to overwrite the pages' object field with the address of the slab.
However, when UMA wants to release these pages, it doesn't know how to
restore the object field, so it sets it to NULL. This change teaches
UMA how to reset the object field to the kernel object.
Crashes reported by: kris
Fix tested by: kris
Fix discussed with: jeff
MFC after: 6 weeks
spinning when readers hold a lock. This spinning is speculative because,
unlike the write case, we can not test whether the owners are running.
- Add speculative read spinning for readers who are blocked by pending
writers while a read lock is still held. This allows the thread to
spin until the write lock succeeds after which it may spin until the
writer has released the lock. This prevents excessive context switches
when readers and writers both hold the lock for brief periods.
Sponsored by: Nokia
the fdesc_allocvp(). The caller of the fdesc_allocvp() expects that the
returned vnode is not reclaimed. Do lock the vnode exclusive and drop
the lock after.
Reported by: pho
Reviewed by: jeff
fixed pri boost with '1' or any priority less than the current thread's
priority with a value greater than two. Default the boost to
PRI_MIN_TIMESHARE to prevent regular user-space threads from starving
threads in the kernel. This prevents these user-threads from also
being scheduled as if they are high fixed-priority kernel threads.
- Restore the setting of lowpri in tdq_choose(). It has to be either here
or in sched_switch(). I accidentally removed it from both places.
Tested by: kris
