Commit Graph

27330 Commits

Author SHA1 Message Date
Johannes Berg
3edaf3e61f mac80211: manage AP netdev carrier state
The AP netdev is really only active when beaconing, so
manage the carrier state accordingly. Also do that for
VLAN interfaces enslaved to a given AP interface.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-11 16:23:48 -04:00
Ashok Nagarajan
fe40cb6274 mac80211: Check basic rates when peering
Section 13.2.3 of IEEE 80211s standard requires BSSBasicRateSet of mesh nodes
to be identical to establish peer link.

Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-11 16:23:47 -04:00
Ashok Nagarajan
9ebb61a23d mac80211: Modify sta_get_rates to give basic rates
Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-11 16:23:47 -04:00
Ashok Nagarajan
657c3e0c41 mac80211: Indicate basic rates when adding rate IEs
Basic rates are added with supported rates IE and extended supported
rates IE.

Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-11 16:23:46 -04:00
Ashok Nagarajan
d934f7d0d6 mac80211: Use mandatory rates as basic rates when starting mesh
Signed-off-by: Ashok Nagarajan <ashok@cozybit.com>
Signed-off-by: Thomas Pedersen <thomas@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-11 16:23:45 -04:00
Samuel Ortiz
b4838d12e1 NFC: Fix the LLCP Tx fragmentation loop
Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Samuel Ortiz <sameo@linux.intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-11 15:09:33 -04:00
Eric Dumazet
a21d45726a tcp: avoid order-1 allocations on wifi and tx path
Marc Merlin reported many order-1 allocations failures in TX path on its
wireless setup, that dont make any sense with MTU=1500 network, and non
SG capable hardware.

After investigation, it turns out TCP uses sk_stream_alloc_skb() and
used as a convention skb_tailroom(skb) to know how many bytes of data
payload could be put in this skb (for non SG capable devices)

Note : these skb used kmalloc-4096 (MTU=1500 + MAX_HEADER +
sizeof(struct skb_shared_info) being above 2048)

Later, mac80211 layer need to add some bytes at the tail of skb
(IEEE80211_ENCRYPT_TAILROOM = 18 bytes) and since no more tailroom is
available has to call pskb_expand_head() and request order-1
allocations.

This patch changes sk_stream_alloc_skb() so that only
sk->sk_prot->max_header bytes of headroom are reserved, and use a new
skb field, avail_size to hold the data payload limit.

This way, order-0 allocations done by TCP stack can leave more than 2 KB
of tailroom and no more allocation is performed in mac80211 layer (or
any layer needing some tailroom)

avail_size is unioned with mark/dropcount, since mark will be set later
in IP stack for output packets. Therefore, skb size is unchanged.

Reported-by: Marc MERLIN <marc@merlins.org>
Tested-by: Marc MERLIN <marc@merlins.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-11 10:11:12 -04:00
Eric Dumazet
87151b8689 net: allow pskb_expand_head() to get maximum tailroom
Marc Merlin reported many order-1 allocations failures in TX path on its
wireless setup, that dont make any sense with MTU=1500 network, and non
SG capable hardware.

Turns out part of the problem comes from pskb_expand_head() not using
ksize() to get exact head size given by kmalloc(). Doing the same thing
than __alloc_skb() allows more tailroom in skb and can prevent future
reallocations.

As a bonus, struct skb_shared_info becomes cache line aligned.

Reported-by: Marc MERLIN <marc@merlins.org>
Tested-by: Marc MERLIN <marc@merlins.org>
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-11 10:10:43 -04:00
Herbert Xu
996304bbea bridge: Do not send queries on multicast group leaves
As it stands the bridge IGMP snooping system will respond to
group leave messages with queries for remaining membership.
This is both unnecessary and undesirable.  First of all any
multicast routers present should be doing this rather than us.
What's more the queries that we send may end up upsetting other
multicast snooping swithces in the system that are buggy.

In fact, we can simply remove the code that send these queries
because the existing membership expiry mechanism doesn't rely
on them anyway.

So this patch simply removes all code associated with group
queries in response to group leave messages.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-11 09:43:13 -04:00
Simon Wunderlich
7a5cc24277 batman-adv: add bridge loop avoidance compile option
The define CONFIG_BATMAN_ADV_BLA switches the bridge loop avoidance
on - skip it, and the bridge loop avoidance is not compiled in.

This is useful if binary size should be saved or the feature is
not needed.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-04-11 14:29:00 +02:00
Simon Wunderlich
38ef3d1d91 batman-adv: form groups in the bridge loop avoidance
backbone gateways may be part of the same LAN, but participate
in different meshes. With this patch, backbone gateways form groups by
applying the groupid of another backbone gateway if it is higher. After
forming the group, they only accept messages from backbone gateways of
the same group.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-04-11 14:28:59 +02:00
Simon Wunderlich
b1a8c04b8a batman-adv: drop STP over batman
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-04-11 14:28:59 +02:00
Simon Wunderlich
fe2da6ff27 batman-adv: add broadcast duplicate check
When multiple backbone gateways relay the same broadcast from the
backbone into the mesh, other nodes in the mesh may receive this
broadcast multiple times. To avoid this, the crc checksums of
received broadcasts are recorded and new broadcast packets with
the same content may be dropped if received by another gateway.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-04-11 14:28:59 +02:00
Simon Wunderlich
20ff9d593f batman-adv: don't let backbone gateways exchange tt entries
As the backbone gateways are connected to the same backbone, they
should announce the same clients on the backbone non-exclusively.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-04-11 14:28:59 +02:00
Simon Wunderlich
db08e6e557 batman-adv: allow multiple entries in tt_global_entries
as backbone gateways will all independently announce the same clients,
also the tt global table must be able to hold multiple originators per
client entry.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-04-11 14:28:59 +02:00
Simon Wunderlich
9bf8e4d425 batman-adv: export claim tables through debugfs
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-04-11 14:28:59 +02:00
Simon Wunderlich
c867305509 batman-adv: make bridge loop avoidance switchable
Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-04-11 14:28:59 +02:00
Simon Wunderlich
23721387c4 batman-adv: add basic bridge loop avoidance code
This second version of the bridge loop avoidance for batman-adv
avoids loops between the mesh and a backbone (usually a LAN).

By connecting multiple batman-adv mesh nodes to the same ethernet
segment a loop can be created when the soft-interface is bridged
into that ethernet segment. A simple visualization of the loop
involving the most common case - a LAN as ethernet segment:

node1  <-- LAN  -->  node2
  |                   |
wifi   <-- mesh -->  wifi

Packets from the LAN (e.g. ARP broadcasts) will circle forever from
node1 or node2 over the mesh back into the LAN.

With this patch, batman recognizes backbone gateways, nodes which are
part of the mesh and backbone/LAN at the same time. Each backbone
gateway "claims" clients from within the mesh to handle them
exclusively. By restricting that only responsible backbone gateways
may handle their claimed clients traffic, loops are effectively
avoided.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-04-11 14:28:58 +02:00
Simon Wunderlich
a7f6ee9493 batman-adv: remove old bridge loop avoidance code
The functionality is to be replaced by an improved implementation,
so first clean up.

Signed-off-by: Simon Wunderlich <siwu@hrz.tu-chemnitz.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-04-11 14:28:58 +02:00
Marek Lindner
8681a1c4dd batman-adv: encourage batman to take shorter routes by changing the default hop penalty
Signed-off-by: Marek Lindner <lindner_marek@yahoo.de>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-04-11 14:28:58 +02:00
Sven Eckelmann
de7aae6570 batman-adv: Remove declaration of only locally used functions
Signed-off-by: Sven Eckelmann <sven@narfation.org>
Acked-by: Antonio Quartulli <ordex@autistici.org>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-04-11 14:28:58 +02:00
Sven Eckelmann
0079d2cef1 batman-adv: Replace bitarray operations with bitmap
bitarray.c consists mostly of functionality that is already available as part
of the standard kernel API. batman-adv could use architecture optimized code
and reduce the binary size by switching to the standard functions.

Signed-off-by: Sven Eckelmann <sven@narfation.org>
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-04-11 14:28:58 +02:00
Antonio Quartulli
c1faead333 batman-adv: use ETH_ALEN instead of hardcoded numeric constants
In packet.h the numeric constant 6 is used instead of the more portable ETH_ALEN
define. This patch substitute any hardcoded value with such define.

Signed-off-by: Antonio Quartulli <ordex@autistici.org>
Acked-by: Sven Eckelmann <sven@narfation.org>
2012-04-11 14:28:58 +02:00
Antonio Quartulli
10e3cd6a25 batman-adv: clean up Kconfig
Signed-off-by: Antonio Quartulli <ordex@autistici.org>
2012-04-11 14:28:58 +02:00
Linus Torvalds
94fb175c04 Merge tag 'dmaengine-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/dmaengine
Pull dmaengine fixes from Dan Williams:

1/ regression fix for Xen as it now trips over a broken assumption
   about the dma address size on 32-bit builds

2/ new quirk for netdma to ignore dma channels that cannot meet
   netdma alignment requirements

3/ fixes for two long standing issues in ioatdma (ring size overflow)
   and iop-adma (potential stack corruption)

* tag 'dmaengine-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/djbw/dmaengine:
  netdma: adding alignment check for NETDMA ops
  ioatdma: DMA copy alignment needed to address IOAT DMA silicon errata
  ioat: ring size variables need to be 32bit to avoid overflow
  iop-adma: Corrected array overflow in RAID6 Xscale(R) test.
  ioat: fix size of 'completion' for Xen
2012-04-10 15:30:16 -07:00
Javier Cardona
d299a1f21e {nl,cfg}80211: Support for mesh synchronization
Report Toffset to userspace.
Let userspace select the mesh synchronization method.

Signed-off-by: Marco Porsch <marco.porsch@s2005.tu-chemnitz.de>
Signed-off-by: Pavel Zubarev <pavel.zubarev@gmail.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 15:20:33 -04:00
Javier Cardona
dbf498fbaf mac80211: Implement mesh synchronization framework
This patch adds MBSS extensible synchronization framework (Sec.
13.13.2 of IEEE Std. 802.11-2012).

The framework is implemented via an ops table which defines the
following functions:

    rx_bcn_presp() - this is called every time a mesh beacon is
received.
    adjust_tbtt() - this is called immediately before a beacon is about
to be transmitted.

The default neighbor offset synchronization defined in the standard is
implemented.  We also provide template functions for vendor specific
methods.

When neighbor offset synchronization is active (which is the default)
mesh neighbors in the same MBSS will track timing offsets to each other
and compensate clock drift.

In our tests we observed that this mesh synchronization implementation
successfully corrected drifts between stations of ~2PPM while
introducing a jitter of ~20us.

It is also possible to test this framework on mac80211_hwsim simulated
phys to see how it behaves under different topologies, over poor links,
etc.

Signed-off-by: Marco Porsch <marco.porsch@s2005.tu-chemnitz.de>
Signed-off-by: Pavel Zubarev <pavel.zubarev@gmail.com>
Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 15:20:31 -04:00
Javier Cardona
9bdd3a6bf8 mac80211: Allow tsf increments via debugfs
Reading and writing back the tsf value via tsf is too slow if one wants
to make small increments to this timer.  With this change you can use
the syntax "+=<some value>" or "-=<some value>" to add or substract a
value from the tsf counter.

Signed-off-by: Javier Cardona <javier@cozybit.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 15:20:30 -04:00
Stanislaw Gruszka
88c868c43b mac80211: sanity check for null SSID
While associated we should never have empty SSID, but life can be full
of surprises, and is allways better to print a warning than crash.

Before memcpy() in ieee80211_probereq_get() check ssid_len instead of
ssid pointer, sice pointer it always passed by "ssidie + 2" expression
to send probe functions, so practically never can be NULL.

Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 15:20:28 -04:00
Johannes Berg
32c5057b22 mac80211: use IEEE80211_NUM_ACS
When comparing hw->queues to determine if the
device is QoS capable, use IEEE80211_NUM_ACS
instead of just 4.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 14:56:10 -04:00
Johannes Berg
4644ae8903 mac80211: lazily stop queues in add_pending
When adding pending SKBs there's no need to
stop all queues, we only need to stop those
that we're adding frames to. Implement that
by lazily stopping a queue as we add an SKB.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 14:54:11 -04:00
Johannes Berg
ada1512526 mac80211: debounce queue stop/wake
When the queue status changes we need to do a fair
bit of work, so ignore no-op changes early.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 14:54:11 -04:00
Johannes Berg
ded81f6ba9 mac80211: decouple # of netdev queues from HW queues
When we get more hardware queues, we'll still want
to only have netdev queues per AC, so set it up in
that way. If the hardware doesn't support QoS (by
not supporting at least 4 queues) the netdevs get
a single queue only (this is no change in behavior
as there are no drivers with 2 or 3 queues today.)

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 14:54:10 -04:00
Johannes Berg
54bcbc695e mac80211: refuse TX queue configuration on non-QoS HW
Drivers that don't support QoS also don't support
setting up their ACs, catch that early. While at
it, remove the input check since cfg80211 does it
now.

Also fix up the restart code to not try to set up
the queues in this case.

Finally also change the tx_conf array to have
IEEE80211_NUM_ACS entries instead of # of queues
since that's what it really needs.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 14:54:10 -04:00
Johannes Berg
a3304b0a17 cfg80211/nl80211: clarify TX queue API
With the plan to change mac80211's queue API to
not map ACs to queues 1:1, it seems necessary to
clarify some APIs that act on ACs rather than on
queues to spell that out explicitly. Do this.

Also verify that the AC number given is valid.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 14:54:09 -04:00
Johannes Berg
8f727ef3c4 mac80211: notify driver of rate control updates
Devices that have internal rate control need to be
notified when the bandwidth or SMPS state changes
just like external rate control algorithms get a
notification now.

Add this notification and clarify the change bits
while at it, the HT_CHANGED bit really meant only
bandwidth changed.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 14:54:08 -04:00
Johannes Berg
7213cf2cb0 mac80211: remove queue stop on rate control update
We currently stop the queue when changing the rate
control between 20/40 MHz in the BSS. This seems to
have been necessary when we actually changed the
channel, but now that we just update the station it
doesn't seem right any more. Remove it.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 14:54:08 -04:00
Johannes Berg
64f68e5d15 mac80211: remove channel type argument from rate_update
The channel type argument to the rate_update()
callback isn't really the correct way to give
the rate control algorithm about the desired
RX bandwidth of the peer.

Remove this argument, and instead update the
STA capabilities with 20/40 appropriately. The
SMPS update done by this callback works in the
same way, so this makes the callback cleaner.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 14:54:08 -04:00
Johannes Berg
24398e39c8 mac80211: set HT channel before association
Changing the channel type during operation is
confusing to some drivers and will be hard to
handle in multi-channel scenarios. Instead of
changing the channel, set it to the right HT
channel before authenticating/associating and
don't change it -- just update the 20/40 MHz
restrictions in rate control as needed when
changed by the AP.

This also fixes a problem that Paul missed in
his fix for the "regulatory makes us deaf"
issue -- when we couldn't use 40 MHz we still
associated saying we were using 40 MHz, which
could in similarly broken APs make us never
even connect successfully.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 14:54:07 -04:00
Johannes Berg
1d98fb122d mac80211: use AC constants
Use the AC constants instead of hard-coding
the numbers with comments.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 14:54:07 -04:00
Johannes Berg
78307daadf mac80211: inline ieee80211_add_pending_skbs
This is a trivial wrapper function, inline it.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 14:54:06 -04:00
Johannes Berg
4670cf7a84 mac80211: make ieee80211_downgrade_queue static
There's no reason for it to not be static.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 14:54:06 -04:00
Johannes Berg
4875d30df5 mac80211: clean up uAPSD TX code
Clean up the code formatting and also replace
the constant 0 by IEEE80211_AC_VO.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 14:54:06 -04:00
Johannes Berg
98aed9fd01 mac80211: fix mesh TX coding style
Fix bad indentation & pointless if nesting.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 14:54:05 -04:00
Johannes Berg
81ddbb5c11 mac80211: don't always advertise remain-on-channel
Not all devices are really capable of implementing
remain-on-channel, even if it is implemented in SW,
as they can't necessarily deal with channel changes
while associated.

Remove the WIPHY_FLAG_HAS_REMAIN_ON_CHANNEL and add
it only if either the driver has remain_on_channel
implemented in the driver/device.

Also add it to all drivers that advertise P2P right
now since those definitely have to have it working.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Acked-by: Luciano Coelho <coelho@ti.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2012-04-10 14:54:04 -04:00
Neal Cardwell
18a223e0b9 tcp: fix tcp_rcv_rtt_update() use of an unscaled RTT sample
Fix a code path in tcp_rcv_rtt_update() that was comparing scaled and
unscaled RTT samples.

The intent in the code was to only use the 'm' measurement if it was a
new minimum.  However, since 'm' had not yet been shifted left 3 bits
but 'new_sample' had, this comparison would nearly always succeed,
leading us to erroneously set our receive-side RTT estimate to the 'm'
sample when that sample could be nearly 8x too high to use.

The overall effect is to often cause the receive-side RTT estimate to
be significantly too large (up to 40% too large for brief periods in
my tests).

Signed-off-by: Neal Cardwell <ncardwell@google.com>
Acked-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-10 14:47:09 -04:00
Eric Dumazet
5fb84b1428 tcp: restore correct limit
Commit c43b874d5d (tcp: properly initialize tcp memory limits) tried
to fix a regression added in commits 4acb4190 & 3dc43e3,
but still get it wrong.

Result is machines with low amount of memory have too small tcp_rmem[2]
value and slow tcp receives : Per socket limit being 1/1024 of memory
instead of 1/128 in old kernels, so rcv window is capped to small
values.

Fix this to match comment and previous behavior.

Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Cc: Jason Wang <jasowang@redhat.com>
Cc: Glauber Costa <glommer@parallels.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-10 14:39:26 -04:00
David S. Miller
ecd159fc5f Merge branch 'master' of git://1984.lsi.us.es/net 2012-04-10 14:38:31 -04:00
David S. Miller
06eb4eafbd Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2012-04-10 14:30:45 -04:00
Glauber Costa
1d62e43657 cgroup: pass struct mem_cgroup instead of struct cgroup to socket memcg
The only reason cgroup was used, was to be consistent with the populate()
interface. Now that we're getting rid of it, not only we no longer need
it, but we also *can't* call it this way.

Since we will no longer rely on populate(), this will be called from
create(). During create, the association between struct mem_cgroup
and struct cgroup does not yet exist, since cgroup internals hasn't
yet initialized its bookkeeping. This means we would not be able
to draw the memcg pointer from the cgroup pointer in these
functions, which is highly undesirable.

Signed-off-by: Glauber Costa <glommer@parallels.com>
Acked-by: Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
CC: Li Zefan <lizefan@huawei.com>
CC: Johannes Weiner <hannes@cmpxchg.org>
CC: Michal Hocko <mhocko@suse.cz>
2012-04-10 10:04:07 -07:00