Avoid touching the curr->preempt_notifier cacheline when not needed.

Provides a small improvement on pipe-bench:

  taskset 01 perf stat --repeat 10 -- perf bench sched pipe

before:

 Performance counter stats for 'perf bench sched pipe' (10 runs):

      12385.016204      task-clock (msec)         #    1.001 CPUs utilized            ( +-  0.34% )
         2,000,023      context-switches          #    0.161 M/sec                    ( +-  0.00% )
                 0      cpu-migrations            #    0.000 K/sec
               175      page-faults               #    0.014 K/sec                    ( +-  0.26% )
    41,376,162,250      cycles                    #    3.341 GHz                      ( +-  0.11% )
    17,389,139,321      stalled-cycles-frontend   #   42.03% frontend cycles idle     ( +-  0.25% )
   <not supported>      stalled-cycles-backend
    68,788,588,003      instructions              #    1.66  insns per cycle
                                                  #    0.25  stalled cycles per insn  ( +-  0.02% )
    13,449,387,620      branches                  # 1085.940 M/sec                    ( +-  0.02% )
        20,880,690      branch-misses             #    0.16% of all branches          ( +-  0.98% )

      12.372646094 seconds time elapsed                                          ( +-  0.34% )

after:

 Performance counter stats for 'perf bench sched pipe' (10 runs):

      12180.936528      task-clock (msec)         #    1.001 CPUs utilized            ( +-  0.33% )
         2,000,077      context-switches          #    0.164 M/sec                    ( +-  0.00% )
                 0      cpu-migrations            #    0.000 K/sec
               174      page-faults               #    0.014 K/sec                    ( +-  0.27% )
    40,691,545,577      cycles                    #    3.341 GHz                      ( +-  0.06% )
    16,446,333,371      stalled-cycles-frontend   #   40.42% frontend cycles idle     ( +-  0.18% )
   <not supported>      stalled-cycles-backend
    68,570,100,387      instructions              #    1.69  insns per cycle
                                                  #    0.24  stalled cycles per insn  ( +-  0.01% )
    13,389,740,014      branches                  # 1099.237 M/sec                    ( +-  0.01% )
        20,175,440      branch-misses             #    0.15% of all branches          ( +-  0.52% )

      12.169253010 seconds time elapsed                                          ( +-  0.33% )
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

preempt_notifier_unregister() documents:

  "This is safe to call from within a preemption notifier."

However, both fire_sched_in_preempt_notifiers() and
fire_sched_out_preempt_notifiers() are using hlist_for_each_entry(),
which is not safe against entry removal during iteration.

Inspection of the KVM code does not reveal any use of
preempt_notifier_unregister() within the preempt notifiers.

Therefore, fix the comment.
Signed-off-by: Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1431881590-1456-1-git-send-email-mathieu.desnoyers@efficios.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Jiri reported a machine stuck in multi_cpu_stop() with
migrate_swap_stop() as function and with the following src,dst cpu
pairs: {11,  4} {13, 11} { 4, 13}

                        4       11      13

cpuM: queue(4 ,13)
                        *Ma
cpuN: queue(13,11)
                                *N      Na
                        *M              Mb
cpuO: queue(11, 4)
                        *O      Oa
                                *Nb
                        *Ob

Where *X denotes the cpu running the queueing of cpu-X and X[ab] denotes
the first/second queued work.

You'll observe the top of the workqueue for each cpu: 4,11,13 to be work
from cpus: M, O, N resp. IOW. deadlock.

Do away with the queueing trickery and introduce lg_double_lock() to
lock both CPUs and fully serialize the stop_two_cpus() callers instead
of the partial (and buggy) serialization we have now.
Reported-by: Jiri Olsa <jolsa@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Rik van Riel <riel@redhat.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150605153023.GH19282@twins.programming.kicks-ass.netSigned-off-by: Ingo Molnar <mingo@kernel.org>

When CONFIG_SCHEDSTATS is enabled, /proc/<pid>/sched prints almost all
sched statistics except sum_sleep_runtime. Since sum_sleep_runtime is
a good info to collect, add this it to /proc/<pid>/sched.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1433751041-11724-4-git-send-email-srikar@linux.vnet.ibm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Within runnable tasks in /proc/sched_debug, vruntime is printed twice,
once as tree-key and again as exec-runtime.

Since exec-runtime isnt populated in !CONFIG_SCHEDSTATS, use this field
to print wait_sum.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1433751041-11724-3-git-send-email-srikar@linux.vnet.ibm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

With !CONFIG_SCHEDSTATS, runnable tasks in /proc/sched_debug has too
many columns than required. Fix this by printing appropriate columns.

While at this, print sum_exec_runtime, since this information is
available even in !CONFIG_SCHEDSTATS case.
Signed-off-by: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1433751041-11724-2-git-send-email-srikar@linux.vnet.ibm.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Changeset a43455a1 ("sched/numa: Ensure task_numa_migrate() checks
the preferred node") fixes an issue where workloads would never
converge on a fully loaded (or overloaded) system.

However, it introduces a regression on less than fully loaded systems,
where workloads converge on a few NUMA nodes, instead of properly
staying spread out across the whole system. This leads to a reduction
in available memory bandwidth, and usable CPU cache, with predictable
performance problems.

The root cause appears to be an interaction between the load balancer
and NUMA balancing, where the short term load represented by the load
balancer differs from the long term load the NUMA balancing code would
like to base its decisions on.

Simply reverting a43455a1 would re-introduce the non-convergence
of workloads on fully loaded systems, so that is not a good option. As
an aside, the check done before a43455a1 only applied to a task's
preferred node, not to other candidate nodes in the system, so the
converge-on-too-few-nodes problem still happens, just to a lesser
degree.

Instead, try to compensate for the impedance mismatch between the load
balancer and NUMA balancing by only ever considering a lesser loaded
node as a destination for NUMA balancing, regardless of whether the
task is trying to move to the preferred node, or to another node.

This patch also addresses the issue that a system with a single
runnable thread would never migrate that thread to near its memory,
introduced by 095bebf6 ("sched/numa: Do not move past the balance
point if unbalanced").

A test where the main thread creates a large memory area, and spawns a
worker thread to iterate over the memory (placed on another node by
select_task_rq_fair), after which the main thread goes to sleep and
waits for the worker thread to loop over all the memory now sees the
worker thread migrated to where the memory is, instead of having all
the memory migrated over like before.

Jirka has run a number of performance tests on several systems: single
instance SpecJBB 2005 performance is 7-15% higher on a 4 node system,
with higher gains on systems with more cores per socket.
Multi-instance SpecJBB 2005 (one per node), linpack, and stream see
little or no changes with the revert of 095bebf6 and this patch.
Reported-by: Artem Bityutski <dedekind1@gmail.com>
Reported-by: Jirka Hladky <jhladky@redhat.com>
Tested-by: Jirka Hladky <jhladky@redhat.com>
Tested-by: Artem Bityutskiy <dedekind1@gmail.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Mel Gorman <mgorman@suse.de>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Srikar Dronamraju <srikar@linux.vnet.ibm.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/20150528095249.3083ade0@annuminas.surriel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Commit 095bebf6 ("sched/numa: Do not move past the balance point
if unbalanced") broke convergence of workloads with just one runnable
thread, by making it impossible for the one runnable thread on the
system to move from one NUMA node to another.

Instead, the thread would remain where it was, and pull all the memory
across to its location, which is much slower than just migrating the
thread to where the memory is.

The next patch has a better fix for the issue that 095bebf6 tried
to address.
Reported-by: Jirka Hladky <jhladky@redhat.com>
Signed-off-by: Rik van Riel <riel@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: dedekind1@gmail.com
Cc: mgorman@suse.de
Link: http://lkml.kernel.org/r/1432753468-7785-2-git-send-email-riel@redhat.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

The optimized task selection logic optimistically selects a new task
to run without first doing a full put_prev_task(). This is so that we
can avoid a put/set on the common ancestors of the old and new task.

Similarly, we should only call check_cfs_rq_runtime() to throttle
eligible groups if they're part of the common ancestry, otherwise it
is possible to end up with no eligible task in the simple task
selection.

Imagine:
		/root
	/prev		/next
	/A		/B

If our optimistic selection ends up throttling /next, we goto simple
and our put_prev_task() ends up throttling /prev, after which we're
going to bug out in set_next_entity() because there aren't any tasks
left.

Avoid this scenario by only throttling common ancestors.
Reported-by: Mohammed Naser <mnaser@vexxhost.com>
Reported-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru>
Signed-off-by: Ben Segall <bsegall@google.com>
[ munged Changelog ]
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Roman Gushchin <klamm@yandex-team.ru>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: pjt@google.com
Fixes: 678d5718 ("sched/fair: Optimize cgroup pick_next_task_fair()")
Link: http://lkml.kernel.org/r/xm26wq1oswoq.fsf@sword-of-the-dawn.mtv.corp.google.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

preempt.h has two seperate "#ifdef CONFIG_PREEMPT" sections: one to
define preempt_enable() and another to define preempt_enable_notrace().

Lets gather both.
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Fengguang Wu <fengguang.wu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1433432349-1021-4-git-send-email-fweisbec@gmail.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

preempt_schedule_context() is a tracing safe preemption point but it's
only used when CONFIG_CONTEXT_TRACKING=y. Other configs have tracing
recursion issues since commit:

  b30f0e3f ("sched/preempt: Optimize preemption operations on __schedule() callers")

introduced function based preemp_count_*() ops.

Lets make it available on all configs and give it a more appropriate
name for its new position.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1433432349-1021-3-git-send-email-fweisbec@gmail.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Since function tracing disables preemption, it needs a safe preemption
point to use when preemption is re-enabled without worrying about tracing
recursion. Ie: to avoid tracing recursion, that preemption point can't
be traced (use of notrace qualifier) and it can't call any traceable
function before that preemption point disables preemption itself, which
disarms the recursion.

preempt_schedule() was fine until commit:

  b30f0e3f ("sched/preempt: Optimize preemption operations on __schedule() callers")

because PREEMPT_ACTIVE (which has the property to disable preemption
and this disarm tracing preemption recursion) was set before calling
any further function.

But that commit introduced the use of preempt_count_add/sub() functions
to set PREEMPT_ACTIVE and because these functions are called before
preemption gets a chance to be disabled, we have a tracing recursion.

preempt_schedule_context() is one of the possible preemption functions
used by tracing. Its special purpose is to avoid tracing recursion
against context tracking. Lets enhance this function to become more
generally tracing safe by disabling preemption with raw accessors, such
that no function is called before preemption gets disabled and disarm
the tracing recursion.

This function is going to become the specific tracing-safe preemption
point in further commit.
Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Steven Rostedt <rostedt@goodmis.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1433432349-1021-2-git-send-email-fweisbec@gmail.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Conflicts:
	arch/sparc/include/asm/topology_64.h
Signed-off-by: Ingo Molnar <mingo@kernel.org>

Pull networking fixes from David Miller:

 1) Various VTI tunnel (mark handling, PMTU) bug fixes from Alexander
    Duyck and Steffen Klassert.

 2) Revert ethtool PHY query change, it wasn't correct.  The PHY address
    selected by the driver running the PHY to MAC connection decides
    what PHY address GET ethtool operations return information from.

 3) Fix handling of sequence number bits for encryption IV generation in
    ESP driver, from Herbert Xu.

 4) UDP can return -EAGAIN when we hit a bad checksum on receive, even
    when there are other packets in the receive queue which is wrong.
    Just respect the error returned from the generic socket recv
    datagram helper.  From Eric Dumazet.

 5) Fix BNA driver firmware loading on big-endian systems, from Ivan
    Vecera.

 6) Fix regression in that we were inheriting the congestion control of
    the listening socket for new connections, the intended behavior
    always was to use the default in this case.  From Neal Cardwell.

 7) Fix NULL deref in brcmfmac driver, from Arend van Spriel.

 8) OTP parsing fix in iwlwifi from Liad Kaufman.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (26 commits)
  vti6: Add pmtu handling to vti6_xmit.
  Revert "net: core: 'ethtool' issue with querying phy settings"
  bnx2x: Move statistics implementation into semaphores
  xen: netback: read hotplug script once at start of day.
  xen: netback: fix printf format string warning
  Revert "netfilter: ensure number of counters is >0 in do_replace()"
  net: dsa: Properly propagate errors from dsa_switch_setup_one
  tcp: fix child sockets to use system default congestion control if not set
  udp: fix behavior of wrong checksums
  sfc: free multiple Rx buffers when required
  bna: fix soft lock-up during firmware initialization failure
  bna: remove unreasonable iocpf timer start
  bna: fix firmware loading on big-endian machines
  bridge: fix br_multicast_query_expired() bug
  via-rhine: Resigning as maintainer
  brcmfmac: avoid null pointer access when brcmf_msgbuf_get_pktid() fails
  mac80211: Fix mac80211.h docbook comments
  iwlwifi: nvm: fix otp parsing in 8000 hw family
  iwlwifi: pcie: fix tracking of cmd_in_flight
  ip_vti/ip6_vti: Preserve skb->mark after rcv_cb call
  ...

Pull Sparc fixes from David Miller:

 1) Setup the core/threads/sockets bitmaps correctly so that 'lscpus'
    and friends operate properly.  Frtom Chris Hyser.

 2) The bit that normally means "Cached Virtually" on sun4v systems,
    actually changes meaning in M7 and later chips.  Fix from Khalid
    Aziz.

 3) One some PCI-E systems we need to probe different OF properties to
    fill in the PCI slot information properly, from Eric Snowberg.

 4) Kill an extraneous memset after kzalloc(), from Christophe Jaillet.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/sparc:
  sparc: Resolve conflict between sparc v9 and M7 on usage of bit 9 of TTE
  sparc64: pci slots information is not populated in sysfs
  sparc: kernel: GRPCI2: Remove a useless memset
  sparc64: Setup sysfs to mark LDOM sockets, cores and threads correctly

Pull virtio fix from Michael Tsirkin:
 "Last-minute virtio fix for 4.1

  This tweaks an exported user-space header to fix build breakage for
  userspace using it"

* tag 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/mst/vhost:
  include/uapi/linux/virtio_balloon.h: include linux/virtio_types.h

Pablo Neira Ayuso says:

====================
Netfilter fix for net

The following patch reverts the ebtables chunk that enforces counters that was
introduced in the recently applied d26e2c9f ('Revert "netfilter: ensure
number of counters is >0 in do_replace()"') since this breaks ebtables.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

Merge tag 'wireless-drivers-for-davem-2015-06-01' of git://git.kernel.org/pub/scm/linux/kernel/git/kvalo/wireless-drivers

Kalle Valo says:

====================
iwlwifi:

* fix OTP parsing 8260
* fix powersave handling for 8260

brcmfmac:

* fix null pointer crash
====================
Signed-off-by: David S. Miller <davem@davemloft.net>

We currently rely on the PMTU discovery of xfrm.
However if a packet is localy sent, the PMTU mechanism
of xfrm tries to to local socket notification what
might not work for applications like ping that don't
check for this. So add pmtu handling to vti6_xmit to
report MTU changes immediately.
Signed-off-by: Steffen Klassert <steffen.klassert@secunet.com>
Signed-off-by: Alexander Duyck <alexander.h.duyck@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This reverts commit f96dee13.

It isn't right, ethtool is meant to manage one PHY instance
per netdevice at a time, and this is selected by the SET
command.  Therefore by definition the GET command must only
return the settings for the configured and selected PHY.
Reported-by: Ben Hutchings <ben@decadent.org.uk>
Signed-off-by: David S. Miller <davem@davemloft.net>

Commit dff173de ("bnx2x: Fix statistics locking scheme") changed the
bnx2x locking around statistics state into using a mutex - but the lock
is being accessed via a timer which is forbidden.

[If compiled with CONFIG_DEBUG_MUTEXES, logs show a warning about
accessing the mutex in interrupt context]

This moves the implementation into using a semaphore [with size '1']
instead.
Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: Ariel Elior <Ariel.Elior@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When we come to tear things down in netback_remove() and generate the
uevent it is possible that the xenstore directory has already been
removed (details below).

In such cases netback_uevent() won't be able to read the hotplug
script and will write a xenstore error node.

A recent change to the hypervisor exposed this race such that we now
sometimes lose it (where apparently we didn't ever before).

Instead read the hotplug script configuration during setup and use it
for the lifetime of the backend device.

The apparently more obvious fix of moving the transition to
state=Closed in netback_remove() to after the uevent does not work
because it is possible that we are already in state=Closed (in
reaction to the guest having disconnected as it shutdown). Being
already in Closed means the toolstack is at liberty to start tearing
down the xenstore directories. In principal it might be possible to
arrange to unregister the device sooner (e.g on transition to Closing)
such that xenstore would still be there but this state machine is
fragile and prone to anger...

A modern Xen system only relies on the hotplug uevent for driver
domains, when the backend is in the same domain as the toolstack it
will run the necessary setup/teardown directly in the correct sequence
wrt xenstore changes.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/xen-netback/netback.c: In function ‘xenvif_tx_build_gops’:
drivers/net/xen-netback/netback.c:1253:8: warning: format ‘%lu’ expects argument of type ‘long unsigned int’, but argument 5 has type ‘int’ [-Wformat=]
        (txreq.offset&~PAGE_MASK) + txreq.size);
        ^

PAGE_MASK's type can vary by arch, so a cast is needed.
Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
----
v2: Cast to unsigned long, since PAGE_MASK can vary by arch.
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

This partially reverts commit 1086bbe9 ("netfilter: ensure number of
counters is >0 in do_replace()") in net/bridge/netfilter/ebtables.c.

Setting rules with ebtables does not work any more with 1086bbe9 place.

There is an error message and no rules set in the end.

e.g.

~# ebtables -t nat -A POSTROUTING --src 12:34:56:78:9a:bc -j DROP
Unable to update the kernel. Two possible causes:
1. Multiple ebtables programs were executing simultaneously. The ebtables
   userspace tool doesn't by default support multiple ebtables programs
running

Reverting the ebtables part of 1086bbe9 makes this work again.
Signed-off-by: Bernhard Thaler <bernhard.thaler@wvnet.at>
Signed-off-by: Pablo Neira Ayuso <pablo@netfilter.org>

Fixes userspace compilation error:

error: unknown type name ‘__virtio16’
  __virtio16 tag;
Signed-off-by: Mikko Rapeli <mikko.rapeli@iki.fi>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

sparc: Resolve conflict between sparc v9 and M7 on usage of bit 9 of TTE

Bit 9 of TTE is CV (Cacheable in V-cache) on sparc v9 processor while
the same bit 9 is MCDE (Memory Corruption Detection Enable) on M7
processor. This creates a conflicting usage of the same bit. Kernel
sets TTE.cv bit on all pages for sun4v architecture which works well
for sparc v9 but enables memory corruption detection on M7 processor
which is not the intent. This patch adds code to determine if kernel
is running on M7 processor and takes steps to not enable memory
corruption detection in TTE erroneously.
Signed-off-by: Khalid Aziz <khalid.aziz@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Add PCI slot numbers within sysfs for PCIe hardware.  Larger
PCIe systems with nested PCI bridges and slots further
down on these bridges were not being populated within sysfs.
This will add ACPI style PCI slot numbers for these systems
since the OF 'slot-names' information is not available on
all PCIe platforms.
Signed-off-by: Eric Snowberg <eric.snowberg@oracle.com>
Reviewed-by: Bob Picco <bob.picco@oracle.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

grpci2priv is allocated using kzalloc, so there is no need to memset it.
Signed-off-by: Christophe Jaillet <christophe.jaillet@wanadoo.fr>
Signed-off-by: David S. Miller <davem@davemloft.net>

While shuffling some code around, dsa_switch_setup_one() was introduced,
and it was modified to return either an error code using ERR_PTR() or a
NULL pointer when running out of memory or failing to setup a switch.

This is a problem for its caler: dsa_switch_setup() which uses IS_ERR()
and expects to find an error code, not a NULL pointer, so we still try
to proceed with dsa_switch_setup() and operate on invalid memory
addresses. This can be easily reproduced by having e.g: the bcm_sf2
driver built-in, but having no such switch, such that drv->setup will
fail.

Fix this by using PTR_ERR() consistently which is both more informative
and avoids for the caller to use IS_ERR_OR_NULL().

Fixes: df197195 ("net: dsa: split dsa_switch_setup into two functions")
Reported-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Tested-by: Andrew Lunn <andrew@lunn.ch>
Signed-off-by: David S. Miller <davem@davemloft.net>

Linux 3.17 and earlier are explicitly engineered so that if the app
doesn't specifically request a CC module on a listener before the SYN
arrives, then the child gets the system default CC when the connection
is established. See tcp_init_congestion_control() in 3.17 or earlier,
which says "if no choice made yet assign the current value set as
default". The change ("net: tcp: assign tcp cong_ops when tcp sk is
created") altered these semantics, so that children got their parent
listener's congestion control even if the system default had changed
after the listener was created.

This commit returns to those original semantics from 3.17 and earlier,
since they are the original semantics from 2007 in 4d4d3d1e ("[TCP]:
Congestion control initialization."), and some Linux congestion
control workflows depend on that.

In summary, if a listener socket specifically sets TCP_CONGESTION to
"x", or the route locks the CC module to "x", then the child gets
"x". Otherwise the child gets current system default from
net.ipv4.tcp_congestion_control. That's the behavior in 3.17 and
earlier, and this commit restores that.

Fixes: 55d8694f ("net: tcp: assign tcp cong_ops when tcp sk is created")
Cc: Florian Westphal <fw@strlen.de>
Cc: Daniel Borkmann <dborkman@redhat.com>
Cc: Glenn Judd <glenn.judd@morganstanley.com>
Cc: Stephen Hemminger <stephen@networkplumber.org>
Signed-off-by: Neal Cardwell <ncardwell@google.com>
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: Yuchung Cheng <ycheng@google.com>
Acked-by: Daniel Borkmann <daniel@iogearbox.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

We have two problems in UDP stack related to bogus checksums :

1) We return -EAGAIN to application even if receive queue is not empty.
   This breaks applications using edge trigger epoll()

2) Under UDP flood, we can loop forever without yielding to other
   processes, potentially hanging the host, especially on non SMP.

This patch is an attempt to make things better.

We might in the future add extra support for rt applications
wanting to better control time spent doing a recv() in a hostile
environment. For example we could validate checksums before queuing
packets in socket receive queue.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Cc: Willem de Bruijn <willemb@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

When Rx packet data must be dropped, all the buffers
associated with that Rx packet must be freed. Extend
and rename efx_free_rx_buffer() to efx_free_rx_buffers()
and loop through all the fragments.
By doing so this patch fixes a possible memory leak.
Signed-off-by: Shradha Shah <sshah@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

Pull vfs fix from Al Viro:
 "Off-by-one in d_walk()/__dentry_kill() race fix.

  It's very hard to hit; possible in the same conditions as the original
  bug, except that you need the skipped branch to contain all the
  remaining evictables, so that the d_walk()-calling loop in
  d_invalidate() decides there's nothing more to do and doesn't go for
  another pass - otherwise that next pass will sweep the sucker.

  So it's not too urgent, but seeing that the fix is obvious and the
  original commit has spread into all -stable branches..."

* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  d_walk() might skip too much

Pull ARM fixes from Russell King:
 "Three fixes this time around:

   - fix a memory leak which occurs when probing performance monitoring
     unit interrupts

   - fix handling of non-PMD aligned end of RAM causing boot failures

   - fix missing syscall trace exit path with syscall tracing enabled
     causing a kernel oops in the audit code"

* 'fixes' of git://ftp.arm.linux.org.uk/~rmk/linux-arm:
  ARM: 8357/1: perf: fix memory leak when probing PMU PPIs
  ARM: fix missing syscall trace exit
  ARM: 8356/1: mm: handle non-pmd-aligned end of RAM

Pull MIPS fixes from Ralf Baechle:
 "MIPS fixes for 4.1 all across the tree"

* 'upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/ralf/linux:
  MIPS: strnlen_user.S: Fix a CPU_DADDI_WORKAROUNDS regression
  MIPS: BMIPS: Fix bmips_wr_vec()
  MIPS: ath79: fix build problem if CONFIG_BLK_DEV_INITRD is not set
  MIPS: Fuloong 2E: Replace CONFIG_USB_ISP1760_HCD by CONFIG_USB_ISP1760
  MIPS: irq: Use DECLARE_BITMAP
  ttyFDC: Fix to use native endian MMIO reads
  MIPS: Fix CDMM to use native endian MMIO reads

Pull turbostat tool fixes from Len Brown:
 "Just one minor kernel dependency in this batch -- added a #define to
  msr-index.h"

* 'turbostat' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
  tools/power turbostat: update version number to 4.7
  tools/power turbostat: allow running without cpu0
  tools/power turbostat: correctly decode of ENERGY_PERFORMANCE_BIAS
  tools/power turbostat: enable turbostat to support Knights Landing (KNL)
  tools/power turbostat: correctly display more than 2 threads/core

Pull SCSI target fixes from Nicholas Bellinger:
 "These are mostly minor fixes, with the exception of the following that
  address fall-out from recent v4.1-rc1 changes:

   - regression fix related to the big fabric API registration changes
     and configfs_depend_item() usage, that required cherry-picking one
     of HCH's patches from for-next to address the issue for v4.1 code.

   - remaining TCM-USER -v2 related changes to enforce full CDB
     passthrough from Andy + Ilias.

  Also included is a target_core_pscsi driver fix from Andy that
  addresses a long standing issue with a Scsi_Host reference being
  leaked on PSCSI device shutdown"

* git://git.kernel.org/pub/scm/linux/kernel/git/nab/target-pending:
  iser-target: Fix error path in isert_create_pi_ctx()
  target: Use a PASSTHROUGH flag instead of transport_types
  target: Move passthrough CDB parsing into a common function
  target/user: Only support full command pass-through
  target/user: Update example code for new ABI requirements
  target/pscsi: Don't leak scsi_host if hba is VIRTUAL_HOST
  target: Fix se_tpg_tfo->tf_subsys regression + remove tf_subsystem
  target: Drop signal_pending checks after interruptible lock acquire
  target: Add missing parentheses
  target: Fix bidi command handling
  target/user: Disallow full passthrough (pass_level=0)
  ISCSI: fix minor memory leak

Merge tag 'hwmon-for-linus-v4.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fixes from Guenter Roeck:
 "Some late hwmon patches, all headed for -stable

   - fix sysfs attribute initialization in nct6775 and nct6683 drivers

   - do not attempt to auto-detect tmp435 on I2C address 0x37

   - ensure iio channel is of type IIO_VOLTAGE in ntc_thermistor driver"

* tag 'hwmon-for-linus-v4.1-rc6' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: (nct6683) Add missing sysfs attribute initialization
  hwmon: (nct6775) Add missing sysfs attribute initialization
  hwmon: (tmp401) Do not auto-detect chip on I2C address 0x37
  hwmon: (ntc_thermistor) Ensure iio channel is of type IIO_VOLTAGE

Ivan Vecera says:

====================
bna: misc bugfixes

These patches fix several bugs found during device initialization debugging.
====================
Signed-off-by: David S. Miller <davem@davemloft.net>