which existed to cleanup the linux_osname mutex. Now that MTX_SYSINIT()
has grown a SYSUNINIT to destroy mutexes on unload, the extra destroy here
was redundant and resulted in panics in debug kernels.
MFC after: 1 week
Reported by: Goran Gajic ggajic at afrodita dot rcub dot bg dot ac dot yu
the second step of approximating cbrt(x). It turns out to be neither
very magic not nor very good. It is just the (2,2) Pade approximation
to 1/cbrt(r) at r = 1, arranged in a strange way to use fewer operations
at a cost of replacing 4 multiplications by 1 division, which is an
especially bad tradeoff on machines where some of the multiplications
can be done in parallel. A Remez rational approximation would give
at least 2 more bits of accuracy, but the (2,2) Pade approximation
already gives 6 more bits than needed. (Changed the comment which
essentially says that it gives 3 more bits.)
Lower order Pade approximations are not quite accurate enough for
double precision but are plenty for float precision. A lower order
Remez rational approximation might be enough for double precision too.
However, rational approximations inherently require an extra division,
and polynomial approximations work well for 1/cbrt(r) at r = 1, so I
plan to switch to using the latter. There are some technical
complications that tend to cost a division in another way.
- Give up endianess support and switch to native-endian format for
accessing hardware structures. In fact embedded processor for
BCM57xx is big-endian architure(MIPS) and it requires native-endian
format for NIC structures.The NIC performs necessary byte/word
swapping depending on programmed endian type.
- With above changes all htole16/htole32 calls were gone.
- Remove bge_vhandle member in softc and changed to use explicit
register access. This may add additional performance penalty
that than that of previous memory access. But most of the access
is performed on initialization phase(e.g. RCB setup), it would be
negligible.
Due to incorrect use of bus_dma(9) in bge(4) it still panics sparc64
system in device detach path. The issue would be fixed in next patch.
Reviewed by: jkim (initial version)
Silence from: ps
Tested by: glebius
Obtained from: NetBSD via OpenBSD
mbuf chain that starts with a cluster containing just MHLEN bytes. This
happened because m_dup called m_get or m_getcl depending on the amount of
data to copy, but then always set the size available in the first mbuf to
MHLEN.
Submitted by: Matt Koivisto <mkoivisto at sandvine dot com>
Approved by: jmg
Silence from: rwatson (mentor)
SMBus busses. Because of limitations in smbus_if.m, the second smbus is
attached to an amdpm1 device that is a child of amdpm0.
Submitted by: Artemiev Igor ai (at) bmc dot brk dot ru
automatically it is possible wait4(2) returns -1 and sets
errno = ECHILD if there were forked children. A user can
set such signal handler e.g. via ``trap "" 20'', see a PR
for the test case. Deal with this case and mark a job as
JOBDONE.
PR: bin/90334
Submitted by: bde
MFC after: 4 weeks
1. Implement a large set of ioctl shims so that the Linux management apps
from LSI will work. This includes infrastructure to support adding, deleting
and rescanning arrays at runtime. This is based on work from Doug Ambrosko,
heavily augmented by LSI and Yahoo.
2. Implement full 64-bit DMA support. Systems with more than 4GB of RAM
can now operate without the cost of bounce buffers. Cards that cannot do
64-bit DMA will automatically revert to using bounce buffers. This option
can be forced off by setting the 'hw.amr.force_sg32" tunable in the loader.
It should only be turned off for debugging purposes. This work was sponsored
by Yahoo.
3. Streamline the command delivery and interrupt handler paths after
much discussion with Dell and LSI. The logic now closely matches the
intended design, making it both more robust and much faster. Certain
i/o failures under heavy load should be fixed with this.
4. Optimize the locking. In the interrupt handler, the card can be checked
for completed commands without any locks held, due to the handler being
implicitely serialized and there being no need to look at any shared data.
Only grab the lock to return the command structure to the free pool. A
small optimization can still be made to collect all of the completions
together and then free them together under a single lock.
Items 3 and 4 significantly increase the performance of the driver. On an
LSI 320-2X card, transactions per second went from 13,000 to 31,000 in my
testing with these changes. However, these changes are still fairly
experimental and shouldn't be merged to 6.x until there is more testing.
Thanks to Doug Ambrosko, LSI, Dell, and Yahoo for contributing towards
this.
to use busdma. Unlike most of the other drivers, but similar to the
if_em driver, pre-allocate the dmamaps at init time instead of allocating
them on the fly when descriptors need to be filled. This isn't ideal right
now because a map is allocated for every descriptor slot in the tx, rx, mini,
and jumbo rings (which is a lot!) in order to simplify the bookkeeping, even
though the driver might support filling only a subset of those slots.
Luckily, maps are typically NULL on i386 and amd64, so the cost isn't
very high. It could be an issue with sparc64, but the driver isn't endian
clean either, and that is a much bigger problem to solve first.
Note that jumbo frame support is under-tested, and I'm not even sure if
it till really works correctly given the evil VM magic that is does.
The changes here attempt to preserve the existing semanitcs.
Thanks to Martin Nillson for contributing the Netgear card for this work.
MFC-After: 3 weeks
class, then it displays various information about the lock and calls a
new function pointer in lock_class (lc_ddb_show) to dump class-specific
information about the lock as well (such as the owner of a mutex or
xlock'ed sx lock). This is easier than staring at hex dumps of locks to
figure out who owns the lock, etc. Note that extending lock_class doesn't
affect the ABI for any kernel modules as the only code that deals with
lock_class structures directly is kern_mutex.c, kern_sx.c, and witness.
MFC after: 1 week
This gives an optimization of between 9 and 22% on Athlons (largest
for cbrt() on amd64 -- from 205 to 159 cycles).
We extracted the sign bit and worked with |x|, and restored the sign
bit as the last step. We avoided branches to a fault by using accesses
to FP values as bits to clear and restore the sign bit. Avoiding
branches is usually good, but the bit access macros are not so good
(especially for setting FP values), and here they always caused pipeline
stalls on Athlons. Even using branches would be faster except on args
that give perfect branch misprediction, since only mispredicted branches
cause stalls, but it possible to avoid touching the sign bit in FP
values at all (except to preserve it in conversions from bits to FP
not related to the sign bit). Do this. The results are identical
except in 2 of the 3 unsupported rounding modes, since all the
approximations use odd rational functions so they work right on strictly
negative values, and the special case of -0 doesn't use an approximation.
originally thought. The BIOS that cleared CPUID_APIC actually managed
to disable the local APIC entirely and even Windows 64 doesn't boot on
it.
Reported by: bz
