- In 8.x and above the run-queue locks are nomore shared even in the
HTT case, so remove the special case.
- The deadlock explained in the removed comment here is still possible
even with different locks, with the contribution of tdq_lock_pair().
An explanation is here:
(hypotesis: a thread needs to migrate on another CPU, thread1 is doing
sched_switch_migrate() and thread2 is the one handling the sched_switch()
request or in other words, thread1 is the thread that needs to migrate
and thread2 is a thread that is going to be preempted, most likely an
idle thread. Also, 'old' is referred to the context (in terms of
run-queue and CPU) thread1 is leaving and 'new' is referred to the
context thread1 is going into. Finally, thread3 is doing tdq_idletd()
or sched_balance() and definitively doing tdq_lock_pair())
* thread1 blocks its td_lock. Now td_lock is 'blocked'
* thread1 drops its old runqueue lock
* thread1 acquires the new runqueue lock
* thread1 adds itself to the new runqueue and sends an IPI_PREEMPT
through tdq_notify() to the new CPU
* thread1 drops the new lock
* thread3, scanning the runqueues, locks the old lock
* thread2 received the IPI_PREEMPT and does thread_lock() with td_lock
pointing to the new runqueue
* thread3 wants to acquire the new runqueue lock, but it can't because
it is held by thread2 so it spins
* thread1 wants to acquire old lock, but as long as it is held by
thread3 it can't
* thread2 going further, at some point wants to switchin in thread1,
but it will wait forever because thread1->td_lock is in blocked state
This deadlock has been manifested mostly on 7.x and reported several time
on mailing lists under the voice 'spinlock held too long'.
Many thanks to des@ for having worked hard on producing suitable textdumps
and Jeff for help on the comment wording.
Reviewed by: jeff
Reported by: des, others
Tested by: des, Giovanni Trematerra
<giovanni dot trematerra at gmail dot com>
(STABLE_7 based version)
we at least don't panic.
We don't really support dual role mode (INITIATOR/TARGET) any more. We
should but it's broken and will take a fair amount of effort to fix
and correctly manage both initiator and target roles sharing the port
database. So, for now, disallow it.
module tries to install the same address again. This extra code
is removed, which was discovered by the removal of a call to
in_ifscrub() in r196714. This call to in_ifscrub is put back here
because the SIOCAIFADDR command can be used to change the prefix
length of an existing alias.
Reviewed by: kmacy
within the system that owns the interface. Packets destined to
the local end point leak to the wire towards the default gateway
if one exists. This behavior is changed as part of the L2/L3
rewrite efforts. The local end point is now reachable within the
system. The inpcb code needs to consider this fact during the
address selection process.
Reviewed by: bz
MFC after: immediately
df(1) and mount(8) output. This is a bit smilar to OpenSolaris and follows
ZFS route of not listing snapshots by default with 'zfs list' command.
- Add UPDATING entry to note that ZFS snapshots are no longer visible in
mount(8) and df(1) output by default.
Reviewed by: kib
MFC after: 3 days
does. This is not POLA violation, because there is no single file system in the
base that use MNT_IGNORE currently, although ZFS snapshots will be mounted with
MNT_IGNORE after next commit.
Reviewed by: kib
MFC after: 3 days
legacy IP handling rather than the IPv6 version.
Reported by: Pegasus Mc Cleaft (ken mthelicon.com)
Tested by: Pegasus Mc Cleaft (ken mthelicon.com)
MFC after: 2 days
X-MFX with: r197139
For some vague reason, it may be possible that scp->cursor_pos exceeds
scp->ysize * scp->xsize. This means that teken_set_cursor() may get
called with an invalid position. Just ignore the old cursor position in
this case.
Reported by: Paul B. Mahol <onemda gmail com>
MFC after: 1 month
1) A lock issue, if we ever had to try again
we would double lock the INP lock.
2) We were allowing (at wrap) associd 0... which really
we cannot allow since 0 normally means in most socket
API calls that we are wishing to effect something on
the INP not TCB.
MFC after: 1 week
by just returning EOPNOTSUPP. This will allow NFS server to fall back to
regular READDIR.
Note that converting inode number to snapshot's vnode is expensive operation.
Snapshots are stored in AVL tree, but based on their names, not inode numbers,
so to convert inode to snapshot vnode we have to interate over all snalshots.
This is not a problem in OpenSolaris, because in their READDIRPLUS
implementation they use VOP_LOOKUP() on d_name, instead of VFS_VGET() on
d_fileno as we do.
PR: kern/125149
Reported by: Weldon Godfrey <wgodfrey@ena.com>
Analysis by: Jaakko Heinonen <jh@saunalahti.fi>
MFC after: 3 days
OFW device tree for PCI bridges and add a new one for PCI Express.
While at it, take advantage of the former for the rman(9) work-
around in jbusppm(4).
the same entry twice. This bug is not fixed yet, but leads to situation
where when try to access corrupted directory the kernel will panic.
Until the bug is properly fixed, try to recover from it and log that it
happened.
Reported by: marck
OpenSolaris bug: 6709336
MFC after: 3 days
network_ipv6->rc.d/netif integration:
- $ipv6_enable is now obsolete. Instead, IPv6 is enabled by
default if the kernel supports it, and $ipv6_network_interfaces
is "none" by default. If you want to use IPv6, define
$ipv6_network_interfaces and $ifconfig_xxx_ipv6.
An interface which is in $network_interfaces and not in
$ipv6_network_interfaces will be marked as "inet6
-auto_linklocal ifdisabled" (see ifconfig(8)).
- $ipv6_ifconfig_xxx is renamed to ifconfig_xxx_ipv6 for
consistency with other address families. The old variables
still work but can be removed in the future. Note that
ipv6_ifconfig_xxx="..." should be replaced with
ifconfig_xxx_ipv6="inet6 ...".
- Receiving ICMPv6 Router Advertisement is not automatically
enabled even if there is no manual configuration of IPv6 in
rc.conf. If you want it, define
ifconfig_xxx_ipv6="inet6 ... accept_rtadv".
- The rc.d/ip6addrctl now chooses address selection policy based
on $ipv6_prefer, not $ipv6_enable. The default is
ipv6_prefer=NO.
- $router* and $ipv6_router* are replaced with $routed_* and
$route6d_* for consistency. The old variables still work but
can be removed in the future.
MFC after: 3 days
and $desc.
The set_rcvar_obsolete() is for displaying an obsolete variable
and the new one. More specifically, a warning is displayed when
a variable is removed or changed in the source tree and the user
still defines the old one.
$router* and $ipv6_router* are replaced with $routed_* and
$route6d_* for consistency. The old variables still work but
can be removed in the future.
MFC after: 3 days
- Add rc.d/stf and rc.d/faith for stf(4) and faith(4).
- Remove rc.d/auto_linklocal and rc.d/network_ipv6.
- Move rc.d/sysctl to just before FILESYSTEMS because rc.d/netif
depends on some sysctl variables.
Reviewed by: brooks
MFC after: 3 days
automatic link-local address configuration:
- Convert a sysctl net.inet6.ip6.accept_rtadv to one for the
default value of a per-IF flag ND6_IFF_ACCEPT_RTADV, not a
global knob. The default value of the sysctl is 0.
- Add a new per-IF flag ND6_IFF_AUTO_LINKLOCAL and convert a
sysctl net.inet6.ip6.auto_linklocal to one for its default
value. The default value of the sysctl is 1.
- Make ND6_IFF_IFDISABLED more robust. It can be used to disable
IPv6 functionality of an interface now.
- Receiving RA is allowed if ip6_forwarding==0 *and*
ND6_IFF_ACCEPT_RTADV is set on that interface. The former
condition will be revisited later to support a "host + router" box
like IPv6 CPE router. The current behavior is compatible with
the older releases of FreeBSD.
- The ifconfig(8) now supports these ND6 flags as well as "nud",
"prefer_source", and "disabled" in ndp(8). The ndp(8) now
supports "auto_linklocal".
Discussed with: bz and jinmei
Reviewed by: bz
MFC after: 3 days
