It is about 2.5 microseconds or roughly 3 times faster to use this
"PIIX" timecounter than the "i8254" timecounter. Resolution is
also 3 times better.
The code cheats and don't register the PCI device, because other pieces
of code want to use it too.
Originally spotted by: msmith
strategy used in the 3Com Linux driver. The new strategy is to use transmit
descriptor polling -- that is, the NIC polls the descriptors to see when
new packets are available for transmission. The advantage to the new scheme
is that no register accesses are needed in the transmit routine. The old
scheme requires several register accesses to stall the TX engine, update the
TX DMA list pointer register, then unstall the TX engine. Hopefully the new
scheme will provide improved transmit performance with less CPU overhead.
This only affects the 3c90xB or 3c90xC cards, not the 3c90x cards. This
means the original 3c900 and 3c905 cards are unaffected. Newer cards include
the 3c900B series, the 3c905B, 3c980, 3c980B, 3c905C and 3c905C, and the
3cSOHO100-TX OfficeConnect.
close PR #13757, however I'm waiting on user feedback before declaring the
PR officially closed. Among other things, this improves UDP transmit
performance, and tx underruns are now detected and the TX start threshold
adjusted accordingly.
far-reaching in fd-land, so you'll want to consult the code for
changes. The biggest change is that now, you don't use
fp->f_ops->fo_foo(fp, bar)
but instead
fo_foo(fp, bar),
which increments and decrements the fp refcount upon entry and exit.
Two new calls, fhold() and fdrop(), are provided. Each does what it
seems like it should, and if fdrop() brings the refcount to zero, the
fd is freed as well.
Thanks to peter ("to hell with it, it looks ok to me.") for his review.
Thanks to msmith for keeping me from putting locks everywhere :)
Reviewed by: peter
- Remove sc_get_scr_stat(). It's not necessary anymore.
- Call ttymalloc() to allocate the struct tty for each vty, rather than
statically declaring an array of struct tty. We still need a statically
allocated struct tty for the first vty which is used for the kernel
console I/O, though.
- Likewise, call ttymalloc() for /dev/sysmouse and /dev/consolectl.
- Delete unnecessary test on the pointer struct tty *tp in some functions.
- Delete unused code in scmouse.c.
WARNING: this change requires you to recompile screen savers!
users have suffered from this breakage, w/o commitment from someone that
they would fix the problems.
This effectively backs out revs 1.{157-160}. It does however fix the
build problem that caused 1.157 to be committed.
If the changes from rev 1.156-1.160 can't be fully tested by the
committer, may I offer posting a diff in the freebsd-current mailing
list for broader testing before inflicting this breakage again.
addaliasu() into addalias() (no operational change) and clarify comments
relating to a trick that vclean() uses.
The fix to BOOTP is yet another hack. Actually, rootfsid handling
is already a major hack. The whole thing needs to be cleaned up.
Reviewed by: David Greenman <dg@root.com>, Alan Cox <alc@cs.rice.edu>
1) Reworked the probe routine
2) Addition of the 574B's product ID.
3) Added useful info when booting verbosely.
Submitted by: Jason Young <doogie@anet-stl.com>
Make a sonewconn3() which takes an extra argument (proc) so new sockets created
with sonewconn() from a user's system call get the correct credentials, not
just the parent's credentials.
WARNING: libdevstat, iostat, vmstat, systat etc etc will need a recompile.
Add devstat_end_transaction_buf() which pulls all the vital data out
of a struct buf which is ready for biodone().
Bug fix: xmradio nolonger experiences a 6Mhz offset after running FXTV
New feature: Automatic Tuner selection for AVerMedia cards with
configuration EEPROMs on (ie the Bt878 based cards)
length for mini receive ring. The max length was MHLEN, however the mbufs
are actually shortened to MHLEN - ETHER_ALIGN to force payload alignment.
PR: 13793
to buffered block devices are allowed. The default is to be backwards
compatible, i.e. reads and writes are allowed.
The idea is for a larger crowd to start running with this disabled and
see what problems, if any, crop up, and then to change the default to
off and see if any problems crop up in the next 6 months prior to
potentially removing support entirely. There are still a few people,
Julian and myself included, who believe the buffered block device
access from usermode to be useful.
Remove use of vnode->v_lastr from buffered block device I/O in
preparation for removal of vnode->v_lastr field, replacing it with
the already existing seqcount metric to detect sequential operation.
Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
previously issued synchronously even if async daemons (nfsiod's) were
available. The commit has been moved from the strategy code to the doio
code in order to asynchronize it.
Removed use of lastr in preparation for removal of vnode->v_lastr. It
has been replaced with seqcount, which is already supported by the system
and, in fact, gives us a better heuristic for sequential detection then
lastr ever did.
Made major performance improvements to the server side commit. The
server previously fsync'd the entire file for each commit rpc. The
server now bawrite()s only those buffers related to the offset/size
specified in the commit rpc.
Note that we do not commit the meta-data yet. This works still needs
to be done.
Note that a further optimization can be done (and has not yet been done)
on the client: we can merge multiple potential commit rpc's into a
single rpc with a greater file offset/size range and greatly reduce
rpc traffic.
Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
syncs the entire underlying file rather then just the requested range,
resulting in huge inefficiencies when the VM system is articulated in
a certain way. The VOP_FSYNC was also found to massively reduce NFS
performance in certain cases.
Change MADV_DONTNEED and MADV_FREE to call vm_page_dontneed() instead
of vm_page_deactivate(). Using vm_page_deactivate() causes all
inactive and cache pages to be recycled before the dontneed/free page
is recycled, effectively flushing our entire VM inactive & cache
queues continuously even if only a few pages are being actively MADV
free'd and reused (such as occurs with a sequential scan of a
memory-mapped file).
Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
from the vnode. (The changeover is undergoing final testing and
will be committed soon).
Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
size != 512 that are configured without a label. The bug should only
have effected swap-backed VN mounts without a label.
Add several major features to VN. In the kernel we add a swap
pre-reservation capability, which can be used to guarentee seek
consistency for swap-backed VN nodes. This also incidently allows
a swap-backed VN filesystem to be recovered after a crash in some
cases (if the same swap blocks happen to be reserved).
We also add a number of new options to vnconfig which do the work
of pre-zeroing or creating/truncating/extending a file which greatly
simplifies using VN in a file-backed configuration.
Add FreeBSD CVS label to sys/sys/vnioctl.h, as well as a new ioctl
flag for the swap pre-reservation feature.
Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
underlying physical sector size when aligning I/O transfer sizes.
It cannot assume 512 bytes.
We assume the underlying sector size is a power of 2. If it isn't,
mmap() will break badly anyway (in the same way mmap broke with NFS
when NFS tried to cache piecemeal write ranges in buffers, before
we enforced read-buffer-before-write-piecemeal for NFS).
Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
Swap space can be freed from an interrupt and so swap reservation and
freeing must occur at splvm.
Add swap_pager_reserve() code to support a new swap pre-reservation
capability for the VN device.
Generally cleanup the swap code by simplifying the swp_pager_meta_build()
static function and consolidating the SWAPBLK_NONE test from a bit test
to an absolute compare. The bit test was left over from a rejected
swap allocation scheme that was not ultimately committed. A few other
minor cleanups were also made.
Reorganize the swap strategy code, again for VN support, to not
reallocate swap when writing as this messes up pre-reservation and
can fragment I/O unnecessarily as VN-baesd disk is messed around with.
Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
current process from the exclusive lock prior to initiating I/O.
This fixes a panic related to swap-backed VN disks
Reviewed by: Alan Cox <alc@cs.rice.edu>, David Greenman <dg@root.com>
Replace various VM related page count calculations strewn over the
VM code with inlines to aid in readability and to reduce fragility
in the code where modules depend on the same test being performed
to properly sleep and wakeup.
Split out a portion of the page deactivation code into an inline
in vm_page.c to support vm_page_dontneed().
add vm_page_dontneed(), which handles the madvise MADV_DONTNEED
feature in a related commit coming up for vm_map.c/vm_object.c. This
code prevents degenerate cases where an essentially active page may
be rotated through a subset of the paging lists, resulting in premature
disposal.
It's GPL'ed of course, but looking over it tonight I learned of Yet Another
Fast EtherLink XL Adapter: the 3c980C server adapter. This is basically
an updated version of the 3c980 that uses the Tornado ASIC instead of the
earlier Hurricane ASIC. The only change here is to add the new PCI device
ID (0x9805) and corresponding table entries.
