All TCP ISNs that are sent out are valid cookies, which allows entries
in the syncache to be dropped and still have the ACK accepted later.
As all entries pass through the syncache, there is no sudden switchover
from cache -> cookies when the cache is full; instead, syncache entries
simply have a reduced lifetime. More details may be found in the
"Resisting DoS attacks with a SYN cache" paper in the Usenix BSDCon 2002
conference proceedings.
Sponsored by: DARPA, NAI Labs
the shutdown request at reboot/halt time.
Disable the printf 'vnlru process getting nowhere, pausing...' and instead
export the count to the debug.vnlru_nowhere sysctl.
of polling interfaces at the lowest possible priority
(this might result in softnetisr being scheduled, but there is
no risk of livelock because they have a higher priority than
this thread).
otherwise breaks on the Alpha arch. I think this is wrong since i'd
actually like to probe for a PC architecture, not for a particular CPU
type. Anyway, now it's again the way it used to be.
by me to make it more efficient. The original code had serious balancing
problems and could also deadlock easily. This code relegates the vnode
reclamation to its own kproc and relaxes the vnode reclamation requirements
to better maintain kern.maxvnodes. This code still doesn't balance as well
as it could, but it does a much better job then the original code.
Approved by: re@freebsd.org
Obtained from: ps, peter, dillon
MFS Assuming: Assuming no problems crop up in Yahoo testing
MFC after: 7 days
remove the check from addupc_task(). It would need sched_lock while
testing the flag anyways.
- Always read sticks while holding sched_lock using a temporary variable
where needed.
- Always init prticks to 0 in ast() to quiet a warning.
sense, and mode select into their 10 byte equivalents. Eventually the
da(4) driver will become more intelligent about this, or at least allow
umass(4) to pass quirks in directly. However, this is a functional
workaround until a better fix is implemented.
- Use the 6 to 10 conversion function to allow the ATAPI and UFI command
sets to emulate 6 byte commands with 10 byte commands.
- Use the ATAPI command set rather than UFI for the ScanLogic SL11R-IDE
as it supports the SYNCH_CACHE command.
- Enable ATAPI command set support.
- Pass READ/WRITE_12 commands through for UFI support as the UFI spec
says they should be supported.
- Update a comment in the UFI translation function since we handle
MODE_SELECT.
temporary storage. In the old NFS code it wasn't at all clear if
the value of `tl' was used across or after macro calls, but I'm
fairly confident that the convention was to keep its use local.
Each ex-macro function now uses a local version of this variable,
so all of the double-indirection goes away.
The only exception to the `local use' rule for `tl' is nfsm_clget(),
which is left unchanged by this commit.
Reviewed by: peter
- The MD functions critical_enter/exit are renamed to start with a cpu_
prefix.
- MI wrapper functions critical_enter/exit maintain a per-thread nesting
count and a per-thread critical section saved state set when entering
a critical section while at nesting level 0 and restored when exiting
to nesting level 0. This moves the saved state out of spin mutexes so
that interlocking spin mutexes works properly.
- Most low-level MD code that used critical_enter/exit now use
cpu_critical_enter/exit. MI code such as device drivers and spin
mutexes use the MI wrappers. Note that since the MI wrappers store
the state in the current thread, they do not have any return values or
arguments.
- mtx_intr_enable() is replaced with a constant CRITICAL_FORK which is
assigned to curthread->td_savecrit during fork_exit().
Tested on: i386, alpha
- Axe inlvtlb_ok as it was completely redundant with smp_active.
- Remove references to non-existent variable and non-existent file
in i386/include/smp.h.
- Don't perform initializations local to each CPU while holding the
ap boot lock on i386 while an AP bootstraps itself.
- Reorganize the AP startup code some to unify the latter half of the
functions to bring an AP up. Eventually this might be broken out into
a MI function in subr_smp.c.
a major slowdown, and re-enable stats overflow interrupts.
For future reference, the bug was in our code, and not
some bug in the 3com chips.
Reviewed by: wpaul
MFC after: 2 days
the link rate - some ich motherboards overclock ac97 out of the box.
Will hopefully replace this with a callibration loop in time for 4.5R
freeze.
Problem reported by Luigi Rizzo and fix derived from his code (put
diff in ich.c rather than ac97.c).
MFC after: 3 days
superblock that is already set up to handle pointer types. This
fixes an accidental change in the superblock size on 64-bit platforms
caused by revision 1.24.
The description field is unused in -stable, so the MFC there is equivalent
to a comment. It can be done at any time, i am just setting a reminder
in 45 days when hopefully we are past 4.5-release.
MFC after: 45 days
variables. Use the -d flag in sysctl(8) to see this information.
Possible extensions to sysctl:
+ report variables that do not have a description
+ given a name, report the oid it maps to.
Note to developers: have a look at your code, there are a number of
variables which do not have a description.
Note to developers: do we want this in 4.5 ? It is a very small change
and very useful for documentation purposes.
Suggested by: Orion Hodson
. The main device node now supports automatic density selection for
commonly used media densities. So you can stuff your 1.44 MB and
720 KB media into your drive and just access /dev/fd0, no questions
asked. It's all that easy, isn't it? :)
. Device density handling has been completely overhauled. The old way
of hardwired kernel density knowledge is no longer there. Instead,
the kernel now implements 16 subdevices per drive. The first
subdevice uses automatic density selection, while the remaining 15
devices are freely programmable. They can be assigned an arbitrary
name of the form /dev/fd[:digit]+.[:digit:]{1,4}, where the second
number is meant to either implement device names that are mnemonic
for their raw capacity (as it used to be), or they can alternatively
be created as "anonymous" devices like fd0.1 through fd0.15,
depending on the taste of the administrator. After creating a
subdevice, it is initialized to the maximal native density of the
respective drive type, so it needs to be customized for other
densities by using fdcontrol(8). Pseudo-partition devices (fd0a
through fd0h) are still supported as symlinks.
. The old hack to use flags 0x1 to always assume drive 0 were there is
no longer supported; this is now supposed to be done by wiring the
devices down from the loader via device flags. On IA32
architectures, the first two drives are looked up in the CMOS
configuration records though. On PCMCIA (i. e., the Y-E Data
controller of the Toshiba Libretto), a single drive is always
assumed.
. Other specialities like disabling the FIFO and not probing the drive
at boot-time are selected by per-controller or per-drive flags, too.
. Unit attentions (media has been changed) are supposed to be detected
now; density autoselection only occurs after a unit attention. (Can
be turned off by a per-drive flag, this will cause each Fdopen() to
perform the autoselection.)
. FM floppies can be handled now (on controllers that actually support
it -- not all do these days).
. Fdopen() can be told to avoid density selection by setting
O_NONBLOCK; this leaves the descriptor in a half-opened state where
only a few ioctls are accepted. This is necessary to run fdformat
on a device that uses automatic density selection (since you cannot
autoselect on an unformatted medium, obviously).
. Just differentiate between a plain old NE765 and the enhanced chips,
but don't try more; the existing code was wrong and only misdetected
the chips anyway.
BUGS and TODOs:
. All documentation update still needs to be done.
. Formatting not-so-standard format yields unpredictable results; i
have yet to figure out why this happens. "Standard" formats like
720 and 1440 KB do work, however.
. rc scripts are needed to setup device nodes with nonstandard
densities (like the old /dev/fdN.MMM we used to have).
. Obtaining device flags from the kernel environment doesn't work yet,
thus currently only drives that are present in (IA32) CMOS are
really detected. Someone who knows the odds and ends about device
flags is needed here, i can't figure out what i'm doing wrong.
. 2.88 MB still needs to be done.
