<feed xmlns='http://www.w3.org/2005/Atom'>
<title>linux.git/net/core, branch v4.5-rc5</title>
<subtitle>Linux kernel source tree</subtitle>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/'/>
<entry>
<title>flow_dissector: Fix unaligned access in __skb_flow_dissector when used by eth_get_headlen</title>
<updated>2016-02-09T12:07:48+00:00</updated>
<author>
<name>Alexander Duyck</name>
<email>aduyck@mirantis.com</email>
</author>
<published>2016-02-09T10:49:54+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=461547f3158978c180d74484d58e82be9b8e7357'/>
<id>461547f3158978c180d74484d58e82be9b8e7357</id>
<content type='text'>
This patch fixes an issue with unaligned accesses when using
eth_get_headlen on a page that was DMA aligned instead of being IP aligned.
The fact is when trying to check the length we don't need to be looking at
the flow label so we can reorder the checks to first check if we are
supposed to gather the flow label and then make the call to actually get
it.

v2:  Updated path so that either STOP_AT_FLOW_LABEL or KEY_FLOW_LABEL can
     cause us to check for the flow label.

Reported-by: Sowmini Varadhan &lt;sowmini.varadhan@oracle.com&gt;
Signed-off-by: Alexander Duyck &lt;aduyck@mirantis.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
This patch fixes an issue with unaligned accesses when using
eth_get_headlen on a page that was DMA aligned instead of being IP aligned.
The fact is when trying to check the length we don't need to be looking at
the flow label so we can reorder the checks to first check if we are
supposed to gather the flow label and then make the call to actually get
it.

v2:  Updated path so that either STOP_AT_FLOW_LABEL or KEY_FLOW_LABEL can
     cause us to check for the flow label.

Reported-by: Sowmini Varadhan &lt;sowmini.varadhan@oracle.com&gt;
Signed-off-by: Alexander Duyck &lt;aduyck@mirantis.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net:Add sysctl_max_skb_frags</title>
<updated>2016-02-09T09:28:06+00:00</updated>
<author>
<name>Hans Westgaard Ry</name>
<email>hans.westgaard.ry@oracle.com</email>
</author>
<published>2016-02-03T08:26:57+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=5f74f82ea34c0da80ea0b49192bb5ea06e063593'/>
<id>5f74f82ea34c0da80ea0b49192bb5ea06e063593</id>
<content type='text'>
Devices may have limits on the number of fragments in an skb they support.
Current codebase uses a constant as maximum for number of fragments one
skb can hold and use.
When enabling scatter/gather and running traffic with many small messages
the codebase uses the maximum number of fragments and may thereby violate
the max for certain devices.
The patch introduces a global variable as max number of fragments.

Signed-off-by: Hans Westgaard Ry &lt;hans.westgaard.ry@oracle.com&gt;
Reviewed-by: Håkon Bugge &lt;haakon.bugge@oracle.com&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Devices may have limits on the number of fragments in an skb they support.
Current codebase uses a constant as maximum for number of fragments one
skb can hold and use.
When enabling scatter/gather and running traffic with many small messages
the codebase uses the maximum number of fragments and may thereby violate
the max for certain devices.
The patch introduces a global variable as max number of fragments.

Signed-off-by: Hans Westgaard Ry &lt;hans.westgaard.ry@oracle.com&gt;
Reviewed-by: Håkon Bugge &lt;haakon.bugge@oracle.com&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>unix: correctly track in-flight fds in sending process user_struct</title>
<updated>2016-02-08T15:30:42+00:00</updated>
<author>
<name>Hannes Frederic Sowa</name>
<email>hannes@stressinduktion.org</email>
</author>
<published>2016-02-03T01:11:03+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=415e3d3e90ce9e18727e8843ae343eda5a58fad6'/>
<id>415e3d3e90ce9e18727e8843ae343eda5a58fad6</id>
<content type='text'>
The commit referenced in the Fixes tag incorrectly accounted the number
of in-flight fds over a unix domain socket to the original opener
of the file-descriptor. This allows another process to arbitrary
deplete the original file-openers resource limit for the maximum of
open files. Instead the sending processes and its struct cred should
be credited.

To do so, we add a reference counted struct user_struct pointer to the
scm_fp_list and use it to account for the number of inflight unix fds.

Fixes: 712f4aad406bb1 ("unix: properly account for FDs passed over unix sockets")
Reported-by: David Herrmann &lt;dh.herrmann@gmail.com&gt;
Cc: David Herrmann &lt;dh.herrmann@gmail.com&gt;
Cc: Willy Tarreau &lt;w@1wt.eu&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Suggested-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The commit referenced in the Fixes tag incorrectly accounted the number
of in-flight fds over a unix domain socket to the original opener
of the file-descriptor. This allows another process to arbitrary
deplete the original file-openers resource limit for the maximum of
open files. Instead the sending processes and its struct cred should
be credited.

To do so, we add a reference counted struct user_struct pointer to the
scm_fp_list and use it to account for the number of inflight unix fds.

Fixes: 712f4aad406bb1 ("unix: properly account for FDs passed over unix sockets")
Reported-by: David Herrmann &lt;dh.herrmann@gmail.com&gt;
Cc: David Herrmann &lt;dh.herrmann@gmail.com&gt;
Cc: Willy Tarreau &lt;w@1wt.eu&gt;
Cc: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Suggested-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
Signed-off-by: Hannes Frederic Sowa &lt;hannes@stressinduktion.org&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>gro: Make GRO aware of lightweight tunnels.</title>
<updated>2016-01-21T02:48:38+00:00</updated>
<author>
<name>Jesse Gross</name>
<email>jesse@kernel.org</email>
</author>
<published>2016-01-21T01:59:49+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=ce87fc6ce3f9f4488546187e3757cf666d9d4a2a'/>
<id>ce87fc6ce3f9f4488546187e3757cf666d9d4a2a</id>
<content type='text'>
GRO is currently not aware of tunnel metadata generated by lightweight
tunnels and stored in the dst. This leads to two possible problems:
 * Incorrectly merging two frames that have different metadata.
 * Leaking of allocated metadata from merged frames.

This avoids those problems by comparing the tunnel information before
merging, similar to how we handle other metadata (such as vlan tags),
and releasing any state when we are done.

Reported-by: John &lt;john.phillips5@hpe.com&gt;
Fixes: 2e15ea39 ("ip_gre: Add support to collect tunnel metadata.")
Signed-off-by: Jesse Gross &lt;jesse@kernel.org&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.com&gt;
Acked-by: Thomas Graf &lt;tgraf@suug.ch&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
GRO is currently not aware of tunnel metadata generated by lightweight
tunnels and stored in the dst. This leads to two possible problems:
 * Incorrectly merging two frames that have different metadata.
 * Leaking of allocated metadata from merged frames.

This avoids those problems by comparing the tunnel information before
merging, similar to how we handle other metadata (such as vlan tags),
and releasing any state when we are done.

Reported-by: John &lt;john.phillips5@hpe.com&gt;
Fixes: 2e15ea39 ("ip_gre: Add support to collect tunnel metadata.")
Signed-off-by: Jesse Gross &lt;jesse@kernel.org&gt;
Acked-by: Eric Dumazet &lt;edumazet@google.com&gt;
Acked-by: Thomas Graf &lt;tgraf@suug.ch&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>soreuseport: fix NULL ptr dereference SO_REUSEPORT after bind</title>
<updated>2016-01-19T19:44:23+00:00</updated>
<author>
<name>Craig Gallek</name>
<email>kraig@google.com</email>
</author>
<published>2016-01-19T19:27:08+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=b4ace4f1ae07691b4f6ea9f3e92efbec083df058'/>
<id>b4ace4f1ae07691b4f6ea9f3e92efbec083df058</id>
<content type='text'>
Marc Dionne discovered a NULL pointer dereference when setting
SO_REUSEPORT on a socket after it is bound.
This patch removes the assumption that at least one socket in the
reuseport group is bound with the SO_REUSEPORT option before other
bind calls occur.

Fixes: e32ea7e74727 ("soreuseport: fast reuseport UDP socket selection")
Reported-by: Marc Dionne &lt;marc.c.dionne@gmail.com&gt;
Signed-off-by: Craig Gallek &lt;kraig@google.com&gt;
Tested-by: Marc Dionne &lt;marc.dionne@auristor.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Marc Dionne discovered a NULL pointer dereference when setting
SO_REUSEPORT on a socket after it is bound.
This patch removes the assumption that at least one socket in the
reuseport group is bound with the SO_REUSEPORT option before other
bind calls occur.

Fixes: e32ea7e74727 ("soreuseport: fast reuseport UDP socket selection")
Reported-by: Marc Dionne &lt;marc.c.dionne@gmail.com&gt;
Signed-off-by: Craig Gallek &lt;kraig@google.com&gt;
Tested-by: Marc Dionne &lt;marc.dionne@auristor.com&gt;
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net</title>
<updated>2016-01-15T21:33:12+00:00</updated>
<author>
<name>Linus Torvalds</name>
<email>torvalds@linux-foundation.org</email>
</author>
<published>2016-01-15T21:33:12+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=4e5448a31d73d0e944b7adb9049438a09bc332cb'/>
<id>4e5448a31d73d0e944b7adb9049438a09bc332cb</id>
<content type='text'>
Pull networking fixes from David Miller:
 "A quick set of bug fixes after there initial networking merge:

  1) Netlink multicast group storage allocator only was tested with
     nr_groups equal to 1, make it work for other values too.  From
     Matti Vaittinen.

  2) Check build_skb() return value in macb and hip04_eth drivers, from
     Weidong Wang.

  3) Don't leak x25_asy on x25_asy_open() failure.

  4) More DMA map/unmap fixes in 3c59x from Neil Horman.

  5) Don't clobber IP skb control block during GSO segmentation, from
     Konstantin Khlebnikov.

  6) ECN helpers for ipv6 don't fixup the checksum, from Eric Dumazet.

  7) Fix SKB segment utilization estimation in xen-netback, from David
     Vrabel.

  8) Fix lockdep splat in bridge addrlist handling, from Nikolay
     Aleksandrov"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (26 commits)
  bgmac: Fix reversed test of build_skb() return value.
  bridge: fix lockdep addr_list_lock false positive splat
  net: smsc: Add support h8300
  xen-netback: free queues after freeing the net device
  xen-netback: delete NAPI instance when queue fails to initialize
  xen-netback: use skb to determine number of required guest Rx requests
  net: sctp: Move sequence start handling into sctp_transport_get_idx()
  ipv6: update skb-&gt;csum when CE mark is propagated
  net: phy: turn carrier off on phy attach
  net: macb: clear interrupts when disabling them
  sctp: support to lookup with ep+paddr in transport rhashtable
  net: hns: fixes no syscon error when init mdio
  dts: hisi: fixes no syscon fault when init mdio
  net: preserve IP control block during GSO segmentation
  fsl/fman: Delete one function call "put_device" in dtsec_config()
  hip04_eth: fix missing error handle for build_skb failed
  3c59x: fix another page map/single unmap imbalance
  3c59x: balance page maps and unmaps
  x25_asy: Free x25_asy on x25_asy_open() failure.
  mlxsw: fix SWITCHDEV_OBJ_ID_PORT_MDB
  ...
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Pull networking fixes from David Miller:
 "A quick set of bug fixes after there initial networking merge:

  1) Netlink multicast group storage allocator only was tested with
     nr_groups equal to 1, make it work for other values too.  From
     Matti Vaittinen.

  2) Check build_skb() return value in macb and hip04_eth drivers, from
     Weidong Wang.

  3) Don't leak x25_asy on x25_asy_open() failure.

  4) More DMA map/unmap fixes in 3c59x from Neil Horman.

  5) Don't clobber IP skb control block during GSO segmentation, from
     Konstantin Khlebnikov.

  6) ECN helpers for ipv6 don't fixup the checksum, from Eric Dumazet.

  7) Fix SKB segment utilization estimation in xen-netback, from David
     Vrabel.

  8) Fix lockdep splat in bridge addrlist handling, from Nikolay
     Aleksandrov"

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (26 commits)
  bgmac: Fix reversed test of build_skb() return value.
  bridge: fix lockdep addr_list_lock false positive splat
  net: smsc: Add support h8300
  xen-netback: free queues after freeing the net device
  xen-netback: delete NAPI instance when queue fails to initialize
  xen-netback: use skb to determine number of required guest Rx requests
  net: sctp: Move sequence start handling into sctp_transport_get_idx()
  ipv6: update skb-&gt;csum when CE mark is propagated
  net: phy: turn carrier off on phy attach
  net: macb: clear interrupts when disabling them
  sctp: support to lookup with ep+paddr in transport rhashtable
  net: hns: fixes no syscon error when init mdio
  dts: hisi: fixes no syscon fault when init mdio
  net: preserve IP control block during GSO segmentation
  fsl/fman: Delete one function call "put_device" in dtsec_config()
  hip04_eth: fix missing error handle for build_skb failed
  3c59x: fix another page map/single unmap imbalance
  3c59x: balance page maps and unmaps
  x25_asy: Free x25_asy on x25_asy_open() failure.
  mlxsw: fix SWITCHDEV_OBJ_ID_PORT_MDB
  ...
</pre>
</div>
</content>
</entry>
<entry>
<title>net: preserve IP control block during GSO segmentation</title>
<updated>2016-01-15T19:35:24+00:00</updated>
<author>
<name>Konstantin Khlebnikov</name>
<email>koct9i@gmail.com</email>
</author>
<published>2016-01-08T12:21:46+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=9207f9d45b0ad071baa128e846d7e7ed85016df3'/>
<id>9207f9d45b0ad071baa128e846d7e7ed85016df3</id>
<content type='text'>
Skb_gso_segment() uses skb control block during segmentation.
This patch adds 32-bytes room for previous control block which
will be copied into all resulting segments.

This patch fixes kernel crash during fragmenting forwarded packets.
Fragmentation requires valid IP CB in skb for clearing ip options.
Also patch removes custom save/restore in ovs code, now it's redundant.

Signed-off-by: Konstantin Khlebnikov &lt;koct9i@gmail.com&gt;
Link: http://lkml.kernel.org/r/CALYGNiP-0MZ-FExV2HutTvE9U-QQtkKSoE--KN=JQE5STYsjAA@mail.gmail.com
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
Skb_gso_segment() uses skb control block during segmentation.
This patch adds 32-bytes room for previous control block which
will be copied into all resulting segments.

This patch fixes kernel crash during fragmenting forwarded packets.
Fragmentation requires valid IP CB in skb for clearing ip options.
Also patch removes custom save/restore in ovs code, now it's redundant.

Signed-off-by: Konstantin Khlebnikov &lt;koct9i@gmail.com&gt;
Link: http://lkml.kernel.org/r/CALYGNiP-0MZ-FExV2HutTvE9U-QQtkKSoE--KN=JQE5STYsjAA@mail.gmail.com
Signed-off-by: David S. Miller &lt;davem@davemloft.net&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>mm: memcontrol: generalize the socket accounting jump label</title>
<updated>2016-01-15T00:00:49+00:00</updated>
<author>
<name>Johannes Weiner</name>
<email>hannes@cmpxchg.org</email>
</author>
<published>2016-01-14T23:21:20+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=80e95fe0fdcde2812c341ad4209d62dc1a7af53b'/>
<id>80e95fe0fdcde2812c341ad4209d62dc1a7af53b</id>
<content type='text'>
The unified hierarchy memory controller is going to use this jump label
as well to control the networking callbacks.  Move it to the memory
controller code and give it a more generic name.

Signed-off-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Reviewed-by: Vladimir Davydov &lt;vdavydov@virtuozzo.com&gt;
Acked-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
The unified hierarchy memory controller is going to use this jump label
as well to control the networking callbacks.  Move it to the memory
controller code and give it a more generic name.

Signed-off-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Acked-by: Michal Hocko &lt;mhocko@suse.com&gt;
Reviewed-by: Vladimir Davydov &lt;vdavydov@virtuozzo.com&gt;
Acked-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: tcp_memcontrol: simplify linkage between socket and page counter</title>
<updated>2016-01-15T00:00:49+00:00</updated>
<author>
<name>Johannes Weiner</name>
<email>hannes@cmpxchg.org</email>
</author>
<published>2016-01-14T23:21:17+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=baac50bbc3cdfd184ebf586b1704edbfcee866df'/>
<id>baac50bbc3cdfd184ebf586b1704edbfcee866df</id>
<content type='text'>
There won't be any separate counters for socket memory consumed by
protocols other than TCP in the future.  Remove the indirection and link
sockets directly to their owning memory cgroup.

Signed-off-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Reviewed-by: Vladimir Davydov &lt;vdavydov@virtuozzo.com&gt;
Acked-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</content>
<content type='xhtml'>
<div xmlns='http://www.w3.org/1999/xhtml'>
<pre>
There won't be any separate counters for socket memory consumed by
protocols other than TCP in the future.  Remove the indirection and link
sockets directly to their owning memory cgroup.

Signed-off-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Reviewed-by: Vladimir Davydov &lt;vdavydov@virtuozzo.com&gt;
Acked-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
</pre>
</div>
</content>
</entry>
<entry>
<title>net: tcp_memcontrol: sanitize tcp memory accounting callbacks</title>
<updated>2016-01-15T00:00:49+00:00</updated>
<author>
<name>Johannes Weiner</name>
<email>hannes@cmpxchg.org</email>
</author>
<published>2016-01-14T23:21:14+00:00</published>
<link rel='alternate' type='text/html' href='https://git.tavy.me/linux.git/commit/?id=e805605c721021879a1469bdae45c6f80bc985f4'/>
<id>e805605c721021879a1469bdae45c6f80bc985f4</id>
<content type='text'>
There won't be a tcp control soft limit, so integrating the memcg code
into the global skmem limiting scheme complicates things unnecessarily.
Replace this with simple and clear charge and uncharge calls--hidden
behind a jump label--to account skb memory.

Note that this is not purely aesthetic: as a result of shoehorning the
per-memcg code into the same memory accounting functions that handle the
global level, the old code would compare the per-memcg consumption
against the smaller of the per-memcg limit and the global limit.  This
allowed the total consumption of multiple sockets to exceed the global
limit, as long as the individual sockets stayed within bounds.  After
this change, the code will always compare the per-memcg consumption to
the per-memcg limit, and the global consumption to the global limit, and
thus close this loophole.

Without a soft limit, the per-memcg memory pressure state in sockets is
generally questionable.  However, we did it until now, so we continue to
enter it when the hard limit is hit, and packets are dropped, to let
other sockets in the cgroup know that they shouldn't grow their transmit
windows, either.  However, keep it simple in the new callback model and
leave memory pressure lazily when the next packet is accepted (as
opposed to doing it synchroneously when packets are processed).  When
packets are dropped, network performance will already be in the toilet,
so that should be a reasonable trade-off.

As described above, consumption is now checked on the per-memcg level
and the global level separately.  Likewise, memory pressure states are
maintained on both the per-memcg level and the global level, and a
socket is considered under pressure when either level asserts as much.

Signed-off-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Reviewed-by: Vladimir Davydov &lt;vdavydov@virtuozzo.com&gt;
Acked-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
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<pre>
There won't be a tcp control soft limit, so integrating the memcg code
into the global skmem limiting scheme complicates things unnecessarily.
Replace this with simple and clear charge and uncharge calls--hidden
behind a jump label--to account skb memory.

Note that this is not purely aesthetic: as a result of shoehorning the
per-memcg code into the same memory accounting functions that handle the
global level, the old code would compare the per-memcg consumption
against the smaller of the per-memcg limit and the global limit.  This
allowed the total consumption of multiple sockets to exceed the global
limit, as long as the individual sockets stayed within bounds.  After
this change, the code will always compare the per-memcg consumption to
the per-memcg limit, and the global consumption to the global limit, and
thus close this loophole.

Without a soft limit, the per-memcg memory pressure state in sockets is
generally questionable.  However, we did it until now, so we continue to
enter it when the hard limit is hit, and packets are dropped, to let
other sockets in the cgroup know that they shouldn't grow their transmit
windows, either.  However, keep it simple in the new callback model and
leave memory pressure lazily when the next packet is accepted (as
opposed to doing it synchroneously when packets are processed).  When
packets are dropped, network performance will already be in the toilet,
so that should be a reasonable trade-off.

As described above, consumption is now checked on the per-memcg level
and the global level separately.  Likewise, memory pressure states are
maintained on both the per-memcg level and the global level, and a
socket is considered under pressure when either level asserts as much.

Signed-off-by: Johannes Weiner &lt;hannes@cmpxchg.org&gt;
Reviewed-by: Vladimir Davydov &lt;vdavydov@virtuozzo.com&gt;
Acked-by: David S. Miller &lt;davem@davemloft.net&gt;
Signed-off-by: Andrew Morton &lt;akpm@linux-foundation.org&gt;
Signed-off-by: Linus Torvalds &lt;torvalds@linux-foundation.org&gt;
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