Add a seqlock in struct neighbour to protect neigh->ha[], and avoid
dirtying neighbour in stress situation (many different flows / dsts)
Dirtying takes place because of read_lock(&n->lock) and n->used writes.
Switching to a seqlock, and writing n->used only on jiffies changes
permits less dirtying.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
When a new dst is used to send a frame, neigh_resolve_output() tries to
associate an struct hh_cache to this dst, calling neigh_hh_init() with
the neigh rwlock write locked.
Most of the time, hh_cache is already known and linked into neighbour,
so we find it and increment its refcount.
This patch changes the logic so that we call neigh_hh_init() with
neighbour lock read locked only, so that fast path can be run in
parallel by concurrent cpus.
This brings part of the speedup we got with commit c7d4426a98
(introduce DST_NOCACHE flag) for non cached dsts, even for cached ones,
removing one of the contention point that routers hit on multiqueue
enabled machines.
Further improvements would need to use a seqlock instead of an rwlock to
protect neigh->ha[], to not dirty neigh too often and remove two atomic
ops.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The current code works like this:
int garbage, status;
socklen_t len = sizeof(status);
/* enable pipe */
setsockopt(fd, SOL_PNPIPE, PNPIPE_ENABLE, &garbage, sizeof(garbage));
/* disable pipe */
setsockopt(fd, SOL_PNPIPE, PNPIPE_DISABLE, &garbage, sizeof(garbage));
/* get status */
getsockopt(fd, SOL_PNPIPE, PNPIPE_INQ, &status, &len);
...which does not follow the usual socket option pattern. This patch
merges all three "options" into a single gettable&settable option,
before Linux 2.6.37 gets out:
int status;
socklen_t len = sizeof(status);
/* enable pipe */
status = 1;
setsockopt(fd, SOL_PNPIPE, PNPIPE_ENABLE, &status, sizeof(status));
/* disable pipe */
status = 0;
setsockopt(fd, SOL_PNPIPE, PNPIPE_ENABLE, &status, sizeof(status));
/* get status */
getsockopt(fd, SOL_PNPIPE, PNPIPE_ENABLE, &status, &len);
This also fixes the error code from EFAULT to ENOTCONN.
Signed-off-by: Rémi Denis-Courmont <remi.denis-courmont@nokia.com>
Cc: Kumar Sanghvi <kumar.sanghvi@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
There's no need for the WDS peer address
to not be const, so make it const.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This is the second step for neighbour RCU conversion.
(first was commit d6bf7817 : RCU conversion of neigh hash table)
neigh_lookup() becomes lockless, but still take a reference on found
neighbour. (no more read_lock()/read_unlock() on tbl->lock)
struct neighbour gets an additional rcu_head field and is freed after an
RCU grace period.
Future work would need to eventually not take a reference on neighbour
for temporary dst (DST_NOCACHE), but this would need dst->_neighbour to
use a noref bit like we did for skb->_dst.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This information is already available in mac80211, we just need to export it
via cfg80211 and nl80211.
Signed-off-by: Bruno Randolf <br1@einfach.org>
Acked-by: Johannes Berg <johannes@sipsolutions.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
This adds API to allow adding per-station GTKs,
updates mac80211 to support it, and also allows
drivers to remove a key from hwaccel again when
this may be necessary due to multiple GTKs.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Allow sysadmins to configure the number of multicast
membership report sent on a link failure event.
Signed-off-by: Flavio Leitner <fleitner@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
David
This is the first step for RCU conversion of neigh code.
Next patches will convert hash_buckets[] and "struct neighbour" to RCU
protected objects.
Thanks
[PATCH net-next] net neigh: RCU conversion of neigh hash table
Instead of storing hash_buckets, hash_mask and hash_rnd in "struct
neigh_table", a new structure is defined :
struct neigh_hash_table {
struct neighbour **hash_buckets;
unsigned int hash_mask;
__u32 hash_rnd;
struct rcu_head rcu;
};
And "struct neigh_table" has an RCU protected pointer to such a
neigh_hash_table.
This means the signature of (*hash)() function changed: We need to add a
third parameter with the actual hash_rnd value, since this is not
anymore a neigh_table field.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
In various situations, a device provides a packet to our stack and we
drop it before it enters protocol stack :
- softnet backlog full (accounted in /proc/net/softnet_stat)
- bad vlan tag (not accounted)
- unknown/unregistered protocol (not accounted)
We can handle a per-device counter of such dropped frames at core level,
and automatically adds it to the device provided stats (rx_dropped), so
that standard tools can be used (ifconfig, ip link, cat /proc/net/dev)
This is a generalization of commit 8990f468a (net: rx_dropped
accounting), thus reverting it.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
The "flags" member of "struct wait_queue_t" is used in several places in
the kernel code without beeing initialized by init_wait(). "flags" is
used in bitwise operations.
If "flags" not initialized then unexpected behaviour may take place.
Incorrect flags might used later in code.
Added initialization of "wait_queue_t.flags" with zero value into
"init_wait".
Signed-off-by: Evgeny Kuznetsov <EXT-Eugeny.Kuznetsov@nokia.com>
[ The bit we care about does end up being initialized by both
prepare_to_wait() and add_to_wait_queue(), so this doesn't seem to
cause actual bugs, but is definitely the right thing to do -Linus ]
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
With all the recent module loading cleanups, we've minimized the code
that sits under module_mutex, fixing various deadlocks and making it
possible to do most of the module loading in parallel.
However, that whole conversion totally missed the rather obscure code
that adds a new module to the list for BUG() handling. That code was
doubly obscure because (a) the code itself lives in lib/bugs.c (for
dubious reasons) and (b) it gets called from the architecture-specific
"module_finalize()" rather than from generic code.
Calling it from arch-specific code makes no sense what-so-ever to begin
with, and is now actively wrong since that code isn't protected by the
module loading lock any more.
So this commit moves the "module_bug_{finalize,cleanup}()" calls away
from the arch-specific code, and into the generic code - and in the
process protects it with the module_mutex so that the list operations
are now safe.
Future fixups:
- move the module list handling code into kernel/module.c where it
belongs.
- get rid of 'module_bug_list' and just use the regular list of modules
(called 'modules' - imagine that) that we already create and maintain
for other reasons.
Reported-and-tested-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Adrian Bunk <bunk@kernel.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
The documentation for NL80211_CMD_REMAIN_ON_CHANNEL
isn't accurate, an interface index is required by
the command. Update it accordingly.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Each family may have some amount of boilerplate
locking code that applies to most, or even all,
commands.
This allows a family to handle such things in
a more generic way, by allowing it to
a) include private flags in each operation
b) specify a pre_doit hook that is called,
before an operation's doit() callback and
may return an error directly,
c) specify a post_doit hook that can undo
locking or similar things done by pre_doit,
and finally
d) include two private pointers in each info
struct passed between all these operations
including doit(). (It's two because I'll
need two in nl80211 -- can be extended.)
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Some drivers cannot handle multiple retry rates specified by the rc
algorithm but instead use their own retry table (for example rt2800).
However, if such a device registers itself with a max_rates value of 1
the rc algorithm cannot make use of the extended information the device
can provide about retried rates. On the other hand, if a device
registers itself with a max_rates value > 1 the rc algorithm assumes
that the device can handle multi rate retries.
Fix this issue by introducing another hw parameter max_report_rates that
can be set to a different value then max_rates to indicate if a device
is capable of reporting more rates then specified in max_rates.
Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Added a nl interface to set the peer bssid of a WDS interface.
Signed-off-by: Bill Jordan <bjordan@rajant.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
The net/cfg80211.h header file isn't exported to
userspace, so there's no need for any kind of
__KERNEL__ protection in it. If it was exported,
everything else in it would need protection as
well, not just the logging stuff ...
Cc:Joe Perches <joe@perches.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
