andre [Mon, 7 Apr 2008 19:09:23 +0000 (19:09 +0000)]
Remove TCP options ordering assumptions in tcp_addoptions(). Ordering
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
- Use a different encoding for lockmgr options: make them encoded by
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.
* Add missing #else in the #ifdef DEBUG section.
* Fix the login in asmc_init().
* Change the INIT2 constant to reflect the same change in the Linux driver.
Maintain and observe a ZBUF_FLAG_IMMUTABLE flag on zero-copy BPF
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.
In in_pcbnotifyall() and in6_pcbnotify(), use LIST_FOREACH_SAFE() and
eliminate unnecessary local variable caching of the list head pointer,
making the code a bit easier to read.
Optimize lockmgr in order to get rid of the pool mutex interlock, of the
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
Introduce vm_reserv_reclaim_contig(). This function is used by
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().
Rewrite node's r/w/q-lock semantics using only atomics instead of mutex
and atomics combination. Mutex is now used only for queue protection.
Also avoid unneded extra swi scheduling calls.
Add a MI intr_event_handle() routine for the non-INTR_FILTER case. This
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
During attach on some de(4) adapters the driver sends out a test packet as
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.
MFp4 (mips2-jnpr):
o Default to -O on mips as well as arm. -O2 has been strongly implicated
in many problems in the past, so we're taking a conservative approach
until the problems are well understood.
This code came from the merged mips2 and Juniper mips repositories.
Warner Losh, Randall Seager, Oleksandr Tymoshenko and Olivier Houchard
worked to merge, debug and integrate this code. This code may also
contain code derived from NetBSD.
If you build a compiler with TARGET_BIG_ENDIAN, and then try to build
a little endian kernel, things break. Be explicit about the endian
choice by setting it in the little endian case as well.
Reintroduce UMA_SLAB_KMAP; however, change its spelling to
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.
Add note about PZERO being obsolete, because so much code uses it.
Feel free to improve the verbage, since this was a compromise between
conflicting feedback I got on my original version.
jeff [Fri, 4 Apr 2008 10:00:46 +0000 (10:00 +0000)]
- Add sysctls at debug.rwlock to control the behavior of the speculative
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.
Add some compatibility code so that software which is built to use the new
struct flock with l_sysid member can work properly on an an old kernel which
doesn't support l_sysid.
The temporary workaround for the call to the vget() without lock type in
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.
jeff [Fri, 4 Apr 2008 01:16:18 +0000 (01:16 +0000)]
- Allow static_boost to specify no boost with '0', traditional kernel
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.
jeff [Fri, 4 Apr 2008 01:04:43 +0000 (01:04 +0000)]
- Don't check for the ITHD pri class in tdq_load_add and rem. 4BSD doesn't
do this either. Simply check P_NOLOAD. It'd be nice if this was
in a thread flag so we didn't have an extra cache miss every time we
add and remove a thread from the run-queue.
Refactor certain ARM bus space methods: instead of having multiple copies of
the same code introduce sys/arm/arm/bus_space_generic.c for a shared set of
routines.
Take the first baby step towards unifying and cleaning up arminit():
- Pull all the code to deal with the trampoline stuff into one
centeralized place and use it from everywhere.
- Some minor style tidiness
Put back the quote from Chinggis Khan removed in rev. 1.259.
The quote predated rev. 1.232, which rev. 1.259 was to correct;
therefore it was protected by the "Don't remove fortunes" rule.
das [Thu, 3 Apr 2008 06:14:51 +0000 (06:14 +0000)]
Fix some corner cases:
- fma(x, y, z) returns z, not NaN, if z is infinite, x and y are finite,
x*y overflows, and x*y and z have opposite signs.
- fma(x, y, z) doesn't generate an overflow, underflow, or inexact exception
if z is NaN or infinite, as per IEEE 754R.
- If the rounding mode is set to FE_DOWNWARD, fma(1.0, 0.0, -0.0) is -0.0,
not +0.0.
KERNBASE + 0x00200000 is the same thing as KERNVIRTADDR on this
platform, so use the latter in preference to the former. This makes
the fake_preload setup be the same between kb920x_machdep.c and
avila_machdep.c....
This update primarily addresses the ability to have both the em
and the igb driver static in the kernel. But it also reflects
some other bug fixes in my development stream at Intel.
PR 122373 is also fixed in this code.
Back out revision 1.6, the addition of "BEFORE: mountcritremote".
mountcritremote REQUIREs FILESYSTEMS, and that script REQUIREs zfs,
so this change is a noop. By removing it we make life a little easier
both for rcorder(8) and for debugging down the road.
PR ports/121363 (& ports/73797) has been committed, so we can now go back
to JB's revision 1.96 change to remove -fno-strict-aliasing from CFLAGS.
This makes the default CFLAGS to match the simple defaults that the
tinderboxes use. By using -fno-strict-aliasing by default we are
choosing to ignore problems in code which had the potential to
shoot ourselves in the foot.
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