1. There was a race condition between a thread unlocking
a umtx and the thread contesting it. If the unlocking
thread won the race it may try to wakeup a thread that
was not yet in msleep(). The contesting thread would then
go to sleep to await a wakeup that would never come. It's
not possible to close the race by using a lock because
calls to casuptr() may have to fault a page in from swap.
Instead, the race was closed by introducing a flag that
the unlocking thread will set when waking up a thread.
The contesting thread will check for this flag before
going to sleep. For now the flag is kept in td_flags,
but it may be better to use some other member or create
a new one because of the possible performance/contention
issues of having to own sched_lock. Thanks to jhb for
pointing me in the right direction on this one.
2. Once a umtx was contested all future locks and unlocks
were happening in the kernel, regardless of whether it
was contested or not. To prevent this from happening,
when a thread locks a umtx it checks the queue for that
umtx and unsets the contested bit if there are no other
threads waiting on it. Again, this is slightly more
complicated than it needs to be because we can't hold
a lock across casuptr(). So, the thread has to check
the queue again after unseting the bit, and reset the
contested bit if it finds that another thread has put
itself on the queue in the mean time.
3. Remove the if... block for unlocking an uncontested
umtx, and replace it with a KASSERT. The _only_ time
a thread should be unlocking a umtx in the kernel is
if it is contested.
Previously, there were two copies of telnet; a non-crypto version
that lived in the usual places, and a crypto version that lived in
crypto/telnet/. The latter was built in a broken manner somewhat akin
to other "contribified" sources. This meant that there were 4 telnets
competing with each other at build time - KerberosIV, Kerberos5,
plain-old-secure and base. KerberosIV is no longer in the running, but
the other three took it in turns to jump all over each other during a
"make buildworld".
As the crypto issue has been clarified, and crypto _calls_ are not
a problem, crypto/telnet has been repo-copied to contrib/telnet,
and with this commit, all telnets are now "contribified". The contrib
path was chosen to not destroy history in the repository, and differs
from other contrib/ entries in that it may be worked on as "normal"
BSD code. There is no dangerous crypto in these sources, only a
very weak system less strong than enigma(1).
Kerberos5 telnet and Secure telnet are now selected by using the usual
macros in /etc/make.conf, and the build process is unsurprising and
less treacherous.
- 5705 doesn't support jumbo frames
- Statistics must be read from registers
- RX return ring must be capped at 512 entries
- Omit initialization of certain device blocks
- Acknowledge link change interrupts by setting the 'link changed'
bit in the status register (used to have no effect)
- Remember to toggle the MI completion bit too
- Set the mbuf low watermark differently (on-chip memory buffers,
not BSD mbufs)
- Don't enable Ethernet@WireSpeed feature for certain 5705 chip revs
- Add additional PCI IDs for 5705 and 5782 parts
- Add a forgotten 5704 PCI ID
Most changes ripped kicking and screaming from the Broadcom linux driver.
Thanks to Paul Saab for sanity testing. (My lack of sanity has been
confirmed.)
code from i386. The code has a slight bogon that interrupts are counted
twice. Once on the ithread dispatch and once on the dispatch for the vector
vmstat -i and systat -vm now contains interrupt counts.
Reviewed by: jake
sync of the NetBSD code.
fix isochornous support for ohci. This gets webcams like my OV511
working on sparc64.
PR: kern/52589
Submitted by: Bruce R. Montague (isochonous support)
Reviewed by: joe among others
Allow set 31 to be used for rules other than 65535.
Set 31 is still special because rules belonging to it are not deleted
by the "ipfw flush" command, but must be deleted explicitly with
"ipfw delete set 31" or by individual rule numbers.
This implement a flexible form of "persistent rules" which you might
want to have available even after an "ipfw flush".
Note that this change does not violate POLA, because you could not
use set 31 in a ruleset before this change.
Suggested by: Paul Richards
Set 31 is still special because rules belonging to it are not deleted
by the "ipfw flush" command, but must be deleted explicitly with
"ipfw delete set 31" or by individual rule numbers.
This implement a flexible form of "persistent rules" which you might
want to have available even after an "ipfw flush".
Note that this change does not violate POLA, because you could not
use set 31 in a ruleset before this change.
sbin/ipfw changes to allow manipulation of set 31 will follow shortly.
Suggested by: Paul Richards
lastest rev of the spec. Use an explicit flag for Fast Recovery. [1]
Fix bug with exiting Fast Recovery on a retransmit timeout
diagnosed by Lu Guohan. [2]
Reviewed by: Thomas Henderson <thomas.r.henderson@boeing.com>
Reported and tested by: Lu Guohan <lguohan00@mails.tsinghua.edu.cn> [2]
Approved by: Thomas Henderson <thomas.r.henderson@boeing.com>,
Sally Floyd <floyd@acm.org> [1]
(or possibly testing) the previous formula worked for the default
constants compiled into inetd, but if you recompiled with different
values of CHTSIZE and CHTGRAN the calculation might not have worked.
PR: 54354
Submitted by: Claus Assmann <ca@sendmail.org>
Submitted by: Jose Marcio Martins da Cruz <Jose-Marcio.Martins@ensmp.fr>
MFC after: 5 days
callback will never be deferred. ATM needs to prevent cell and packet
ordering. Also use the default mutex and lock functions (those that
panic) for the tag creation.
