as otherwise the junk it contains may cause uhub_explore to give
up without ever trying to restart the port. This fixes the following
errors I was seeing with a VIA UHCI controller:
uhub0: port error, restarting port 1
uhub0: port error, giving up port 1
(time grows downward)
thread 1 thread 2
------------|------------
dec ref_cnt |
| dec ref_cnt <-- ref_cnt now zero
cmpset |
free all |
return |
|
alloc again,|
reuse prev |
ref_cnt |
| cmpset, read
| already freed
| ref_cnt
------------|------------
This should fix that by performing only a single
atomic test-and-set that will serve to decrement
the ref_cnt, only if it hasn't changed since the
earlier read, otherwise it'll loop and re-read.
This forces ordering of decrements so that truly
the thread which did the LAST decrement is the
one that frees.
This is how atomic-instruction-based refcnting
should probably be handled.
Submitted by: Julian Elischer
internal reference counters, UMA_ZONE_NOFREE. This way, those slabs
(with their ref counts) will be effectively type-stable, then using
a trick like this on the refcount is no longer dangerous:
MEXT_REM_REF(m);
if (atomic_cmpset_int(m->m_ext.ref_cnt, 0, 1)) {
if (m->m_ext.ext_type == EXT_PACKET) {
uma_zfree(zone_pack, m);
return;
} else if (m->m_ext.ext_type == EXT_CLUSTER) {
uma_zfree(zone_clust, m->m_ext.ext_buf);
m->m_ext.ext_buf = NULL;
} else {
(*(m->m_ext.ext_free))(m->m_ext.ext_buf,
m->m_ext.ext_args);
if (m->m_ext.ext_type != EXT_EXTREF)
free(m->m_ext.ref_cnt, M_MBUF);
}
}
uma_zfree(zone_mbuf, m);
Previously, a second thread hitting the above cmpset might
actually read the refcnt AFTER it has already been freed. A very
rare occurance. Now we'll know that it won't be freed, though.
Spotted by: julian, pjd
all of the interface between the driver and the bus. This will enable
us to stop special casing eisa bus attachments in modules and treat them
like we treat all other busses.
In the longer run, we need to eliminate much (all?) of these interfaces
and switch to using the standard bus_alloc_resource(), but that's not
done right now.
# I've not updated the modules to include eisa, etc, just yet
Tested on: Compaq Proliant 3000/333 purchased for eisa work
mode. The 5704 apparently has some s00p3r s33kr1t registers for setting
the advertisement of pause frame ability (i.e flow control) when in
autoneg mode. If we don't set these registers correctly, we may not
be able to negotiate a proper link with some switches. (Symptom is that
the NIC reports the link as up (PCS synched) but no traffic can be
exchanged.)
PR: kern/67598
Add two new functions: ttyref() and ttyrel(). ttymalloc() creates a struct
tty with a reference count of one. when ttyrel sees the count go to zero,
struct tty is freed.
Hold references for open ttys and for ttys which are controlling terminal
for sessions.
Until drivers start using ttyrel(), this commit will make no difference.
different cards that matched vendor/id, but weren't wi cards. This is
because the vendor foolishly didn't have unique product ids. Symbol
has a serial card that would otherwise match the wi driver, for
example...
Taken from a patch for xe posted by: Carlos Velasco
recursive entering of the socket code from the routing code:
- Modify rt_dispatch() to bundle up the sockaddr family, if any,
associated with a pending mbuf to dispatch to routing sockets, in
an m_tag on the mbuf.
- Allocate NETISR_ROUTE for use by routing sockets.
- Introduce rtsintrq, an ifqueue to be used by the netisr, and
introduce rts_input(), a function to unbundle the tagged sockaddr
and inject the mbuf and address into raw_input(), which previously
occurred in rt_dispatch().
- Introduce rts_init() to initialize rtsintrq, its mutex, and
register the netisr. Perform this at the same point in system
initialization as setup of the domains.
This change introduces asynchrony between the generation of a
pending routing socket message and delivery to sockets for use
by userspace. It avoids socket->routing->rtsock->socket use and
helps to avoid lock order reversals between the routing code and
socket code (in particular, raw socket control blocks), as route
locks are held over calls to rt_dispatch().
Reviewed by: "George V.Neville-Neil" <gnn@neville-neil.com>
Conceptual head nod by: sam
pmap_extract() already does it.
In pmap_enter(), opa has already been masked so don't do it again.
Wrap a long line (recent transgression).
Use trunc_page() in pmap_mapdev() instead of anding with PG_FRAME, since
that is what we really meant.
Submitted by: alc (first item)
- export the rest of the cpu features (and amd's features).
- turn on EFER_NXE, depending on the NX amd feature bit
- reorg the identcpu stuff a bit in order to stop treating the
amd features as second class features (since it is now a primary feature
bit set) and make it easier to export.
lives in the top 12 'available' bits. atop() in the PHYS_TO_VM_PAGE()
macro only masks off the lower bits (by accident) and the upper bits
in the 64 bit ptes turn into "interesting" index values.
pmap_remove() would be called with a huge range and we'd stride across
it in only 2MB chunks. This would manifest as massive cpu time and a
largely unresponsive system during hard swap. Instead, check the higher
page directories which means we can run pmap_remove() in just a few
hundred loop iterations instead of millions since we can process
address space in chunks of 512GB and 1GB as well as 2MB.
Eternal thanks to: tmm
when I reordered events in accept1() to allocate a file descriptor
earlier, I didn't properly update use of goto on exit to unwind for
cases where the file descriptor is now held, but wasn't previously.
The result was that, in the event of accept() on a non-blocking socket,
or in the event of a socket error, a file descriptor would be leaked.
This ended up being non-fatal in many cases, as the file descriptor
would be properly GC'd on process exit, so only showed up for processes
that do a lot of non-blocking accept() calls, and also live for a long
time (such as qmail).
This change updates the use of goto targets to do additional unwinding.
Eyes provided by: Brian Feldman <green@freebsd.org>
Feet, hands provided by: Stefan Ehmann <shoesoft@gmx.net>,
Dimitry Andric <dimitry@andric.com>
Arjan van Leeuwen <avleeuwen@piwebs.com>
which doesn't support ACPI power states. Return AE_NOT_FOUND for these
cases and don't print the warning message. Also, print the name of the
handle instead of device when unable to switch states. The device is often
not attached at this point and so its name is NULL, which doesn't help
debugging.
