Commit graph

49,638 commits

Author SHA1 Message Date
Ingo Molnar
2d84e023cb Merge branch 'rcu/next' of git://git.kernel.org/pub/scm/linux/kernel/git/paulmck/linux-rcu into core/rcu
Pull the v3.5 RCU tree from Paul E. McKenney:

 1)	A set of improvements and fixes to the RCU_FAST_NO_HZ feature
	(with more on the way for 3.6).  Posted to LKML:
	https://lkml.org/lkml/2012/4/23/324 (commits 1-3 and 5),
	https://lkml.org/lkml/2012/4/16/611 (commit 4),
	https://lkml.org/lkml/2012/4/30/390 (commit 6), and
	https://lkml.org/lkml/2012/5/4/410 (commit 7, combined with
	the other commits for the convenience of the tester).

 2)	Changes to make rcu_barrier() avoid disrupting execution of CPUs
	that have no RCU callbacks.  Posted to LKML:
	https://lkml.org/lkml/2012/4/23/322.

 3)	A couple of commits that improve the efficiency of the interaction
	between preemptible RCU and the scheduler, these two being all
	that survived an abortive attempt to allow preemptible RCU's
	__rcu_read_lock() to be inlined.  The full set was posted to
	LKML at https://lkml.org/lkml/2012/4/14/143, and the first and
	third patches of that set remain.

 4)	Lai Jiangshan's algorithmic implementation of SRCU, which includes
	call_srcu() and srcu_barrier().  A major feature of this new
	implementation is that synchronize_srcu() no longer disturbs
	the execution of other CPUs.  This work is based on earlier
	implementations by Peter Zijlstra and Paul E. McKenney.  Posted to
	LKML: https://lkml.org/lkml/2012/2/22/82.

 5)	A number of miscellaneous bug fixes and improvements which were
	posted to LKML at: https://lkml.org/lkml/2012/4/23/353 with
	subsequent updates posted to LKML.

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-05-14 08:41:46 +02:00
Linus Torvalds
4a873f5399 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David S. Miller:

 1) Since we do RCU lookups on ipv4 FIB entries, we have to test if the
    entry is dead before returning it to our caller.

 2) openvswitch locking and packet validation fixes from Ansis Atteka,
    Jesse Gross, and Pravin B Shelar.

 3) Fix PM resume locking in IGB driver, from Benjamin Poirier.

 4) Fix VLAN header handling in vhost-net and macvtap, from Basil Gor.

 5) Revert a bogus network namespace isolation change that was causing
    regressions on S390 networking devices.

 6) If bonding decides to process and handle a LACPDU frame, we
    shouldn't bump the rx_dropped counter.  From Jiri Bohac.

 7) Fix mis-calculation of available TX space in r8169 driver when doing
    TSO, which can lead to crashes and/or hung device.  From Julien
    Ducourthial.

 8) SCTP does not validate cached routes properly in all cases, from
    Nicolas Dichtel.

 9) Link status interrupt needs to be handled in ks8851 driver, from
    Stephen Boyd.

10) Use capable(), not cap_raised(), in connector/userns netlink code.
    From Eric W. Biederman via Andrew Morton.

11) Fix pktgen OOPS on module unload, from Eric Dumazet.

12) iwlwifi under-estimates SKB truesizes, also from Eric Dumazet.

13) Cure division by zero in SFC driver, from Ben Hutchings.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (26 commits)
  ks8851: Update link status during link change interrupt
  macvtap: restore vlan header on user read
  vhost-net: fix handle_rx buffer size
  bonding: don't increase rx_dropped after processing LACPDUs
  connector/userns: replace netlink uses of cap_raised() with capable()
  sctp: check cached dst before using it
  pktgen: fix crash at module unload
  Revert "net: maintain namespace isolation between vlan and real device"
  ehea: fix losing of NEQ events when one event occurred early
  igb: fix rtnl race in PM resume path
  ipv4: Do not use dead fib_info entries.
  r8169: fix unsigned int wraparound with TSO
  sfc: Fix division by zero when using one RX channel and no SR-IOV
  openvswitch: Validation of IPv6 set port action uses IPv4 header
  net: compare_ether_addr[_64bits]() has no ordering
  cdc_ether: Ignore bogus union descriptor for RNDIS devices
  bnx2x: bug fix when loading after SAN boot
  e1000: Silence sparse warnings by correcting type
  igb, ixgbe: netdev_tx_reset_queue incorrectly called from tx init path
  openvswitch: Release rtnl_lock if ovs_vport_cmd_build_info() failed.
  ...
2012-05-12 12:57:01 -07:00
Paul E. McKenney
dc36be4419 Merge branches 'barrier.2012.05.09a', 'fixes.2012.04.26a', 'inline.2012.05.02b' and 'srcu.2012.05.07b' into HEAD
barrier:  Reduce the amount of disturbance by rcu_barrier() to the rest of
    	the system.  This branch also includes improvements to
    	RCU_FAST_NO_HZ, which are included here due to conflicts.
fixes:  Miscellaneous fixes.
inline:  Remaining changes from an abortive attempt to inline
    	preemptible RCU's __rcu_read_lock().  These are (1) making
    	exit_rcu() avoid unnecessary work and (2) avoiding having
    	preemptible RCU record a blocked thread when the scheduler
    	declines to do a context switch.
srcu:	Lai Jiangshan's algorithmic implementation of SRCU, including
    	call_srcu().
2012-05-11 10:14:21 -07:00
Nicolas Dichtel
e0268868ba sctp: check cached dst before using it
dst_check() will take care of SA (and obsolete field), hence
IPsec rekeying scenario is taken into account.

Signed-off-by: Nicolas Dichtel <nicolas.dichtel@6wind.com>
Acked-by: Vlad Yaseivch <vyasevich@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-10 23:15:47 -04:00
David S. Miller
59b9997bab Revert "net: maintain namespace isolation between vlan and real device"
This reverts commit 8a83a00b07.

It causes regressions for S390 devices, because it does an
unconditional DST drop on SKBs for vlans and the QETH device
needs the neighbour entry hung off the DST for certain things
on transmit.

Arnd can't remember exactly why he even needed this change.

Conflicts:

	drivers/net/macvlan.c
	net/8021q/vlan_dev.c
	net/core/dev.c

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-10 23:03:34 -04:00
Paul E. McKenney
21e52e1566 rcu: Make RCU_FAST_NO_HZ handle timer migration
The current RCU_FAST_NO_HZ assumes that timers do not migrate unless a
CPU goes offline, in which case it assumes that the CPU will have to come
out of dyntick-idle mode (cancelling the timer) in order to go offline.
This is important because when RCU_FAST_NO_HZ permits a CPU to enter
dyntick-idle mode despite having RCU callbacks pending, it posts a timer
on that CPU to force a wakeup on that CPU.  This wakeup ensures that the
CPU will eventually handle the end of the grace period, including invoking
its RCU callbacks.

However, Pascal Chapperon's test setup shows that the timer handler
rcu_idle_gp_timer_func() really does get invoked in some cases.  This is
problematic because this can cause the CPU that entered dyntick-idle
mode despite still having RCU callbacks pending to remain in
dyntick-idle mode indefinitely, which means that its RCU callbacks might
never be invoked.  This situation can result in grace-period delays or
even system hangs, which matches Pascal's observations of slow boot-up
and shutdown (https://lkml.org/lkml/2012/4/5/142).  See also the bugzilla:

	https://bugzilla.redhat.com/show_bug.cgi?id=806548

This commit therefore causes the "should never be invoked" timer handler
rcu_idle_gp_timer_func() to use smp_call_function_single() to wake up
the CPU for which the timer was intended, allowing that CPU to invoke
its RCU callbacks in a timely manner.

Reported-by: Pascal Chapperon <pascal.chapperon@wanadoo.fr>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-05-09 14:26:56 -07:00
Johannes Berg
1c430a727f net: compare_ether_addr[_64bits]() has no ordering
Neither compare_ether_addr() nor compare_ether_addr_64bits()
(as it can fall back to the former) have comparison semantics
like memcmp() where the sign of the return value indicates sort
order. We had a bug in the wireless code due to a blind memcmp
replacement because of this.

A cursory look suggests that the wireless bug was the only one
due to this semantic difference.

Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-07 19:21:29 -04:00
Linus Torvalds
18b15fcde7 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes form Peter Anvin

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  intel_mid_powerbtn: mark irq as IRQF_NO_SUSPEND
  arch/x86/platform/geode/net5501.c: change active_low to 0 for LED driver
  x86, relocs: Remove an unused variable
  asm-generic: Use __BITS_PER_LONG in statfs.h
  x86/amd: Re-enable CPU topology extensions in case BIOS has disabled it
2012-05-06 12:19:38 -07:00
Linus Torvalds
59068e369b Merge branch 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux
Pull an ACPI patch from Len Brown:
 "It fixes a D3 issue new in 3.4-rc1."

By Lin Ming via Len Brown:
* 'release' of git://git.kernel.org/pub/scm/linux/kernel/git/lenb/linux:
  ACPI: Fix D3hot v D3cold confusion
2012-05-05 10:06:06 -07:00
Lin Ming
1cc0c998fd ACPI: Fix D3hot v D3cold confusion
Before this patch, ACPI_STATE_D3 incorrectly referenced D3hot
in some places, but D3cold in other places.

After this patch, ACPI_STATE_D3 always means ACPI_STATE_D3_COLD;
and all references to D3hot use ACPI_STATE_D3_HOT.

ACPI's _PR3 method is used to enter both D3hot and D3cold states.
What distinguishes D3hot from D3cold is the presence _PR3
(Power Resources for D3hot)  If these resources are all ON,
then the state is D3hot.  If _PR3 is not present,
or all _PR0 resources for the devices are OFF,
then the state is D3cold.

This patch applies after Linux-3.4-rc1.
A future syntax cleanup may remove ACPI_STATE_D3
to emphasize that it always means ACPI_STATE_D3_COLD.

Signed-off-by: Lin Ming <ming.m.lin@intel.com>
Acked-by: Rafael J. Wysocki <rjw@sisk.pl>
Reviewed-by: Aaron Lu <aaron.lu@amd.com>
Signed-off-by: Len Brown <len.brown@intel.com>
2012-05-05 01:19:52 -04:00
Linus Torvalds
4f988f152e seqlock: add 'raw_seqcount_begin()' function
The normal read_seqcount_begin() function will wait for any current
writers to exit their critical region by looping until the sequence
count is even.

That "wait for sequence count to stabilize" is the right thing to do if
the read-locker will just retry the whole operation on contention: no
point in doing a potentially expensive reader sequence if we know at the
beginning that we'll just end up re-doing it all.

HOWEVER.  Some users don't actually retry the operation, but instead
will abort and do the operation with proper locking.  So the sequence
count case may be the optimistic quick case, but in the presense of
writers you may want to do full locking in order to guarantee forward
progress.  The prime example of this would be the RCU name lookup.

And in that case, you may well be better off without the "retry early",
and are in a rush to instead get to the failure handling.  Thus this
"raw" interface that just returns the sequence number without testing it
- it just forces the low bit to zero so that read_seqcount_retry() will
always fail such a "active concurrent writer" scenario.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-04 15:13:54 -07:00
Linus Torvalds
2f62427862 Fix __read_seqcount_begin() to use ACCESS_ONCE for sequence value read
We really need to use a ACCESS_ONCE() on the sequence value read in
__read_seqcount_begin(), because otherwise the compiler might end up
reloading the value in between the test and the return of it.  As a
result, it might end up returning an odd value (which means that a write
is in progress).

If the reader is then fast enough that that odd value is still the
current one when the read_seqcount_retry() is done, we might end up with
a "successful" read sequence, even despite the concurrent write being
active.

In practice this probably never really happens - there just isn't
anything else going on around the read of the sequence count, and the
common case is that we end up having a read barrier immediately
afterwards.

So the code sequence in which gcc might decide to reaload from memory is
small, and there's no reason to believe it would ever actually do the
reload.  But if the compiler ever were to decide to do so, it would be
incredibly annoying to debug.  Let's just make sure.

Cc: stable@kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-04 14:46:02 -07:00
Linus Torvalds
c42f1d4b52 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net
Pull networking fixes from David Miller:

 1) Transfer padding was wrong for full-speed USB in ASIX driver, fix
    from Ingo van Lil.

 2) Propagate the negative packet offset fix into the PowerPC BPF JIT.
    From Jan Seiffert.

 3) dl2k driver's private ioctls were letting unprivileged tasks make
    MII writes and other ugly bits like that.  Fix from Jeff Mahoney.

 4) Fix TX VLAN and RX packet drops in ucc_geth, from Joakim Tjernlund.

 5) OOPS and network namespace fixes in IPVS from Hans Schillstrom and
    Julian Anastasov.

 6) Fix races and sleeping in locked context bugs in drop_monitor, from
    Neil Horman.

 7) Fix link status indication in smsc95xx driver, from Paolo Pisati.

 8) Fix bridge netfilter OOPS, from Peter Huang.

 9) L2TP sendmsg can return on error conditions with the socket lock
    held, oops.  Fix from Sasha Levin.

10) udp_diag should return meaningful values for socket memory usage,
    from Shan Wei.

11) Eric Dumazet is so awesome he gets his own section:

       Socket memory cgroup code (I never should have applied those
       patches, grumble...) made erroneous changes to
       sk_sockets_allocated_read_positive().  It was changed to
       use percpu_counter_sum_positive (which requires BH disabling)
       instead of percpu_counter_read_positive (which does not).
       Revert back to avoid crashes and lockdep warnings.

       Adjust the default tcp_adv_win_scale and tcp_rmem[2] values
       to fix throughput regressions.  This is necessary as a result
       of our more precise skb->truesize tracking.

       Fix SKB leak in netem packet scheduler.

12) New device IDs for various bluetooth devices, from Manoj Iyer,
    AceLan Kao, and Steven Harms.

13) Fix command completion race in ipw2200, from Stanislav Yakovlev.

14) Fix rtlwifi oops on unload, from Larry Finger.

15) Fix hard_mtu when adjusting hard_header_len in smsc95xx driver.
    From Stephane Fillod.

16) ehea driver registers it's IRQ before all the necessary state is
    setup, resulting in crashes.  Fix from Thadeu Lima de Souza
    Cascardo.

17) Fix PHY connection failures in davinci_emac driver, from Anatolij
    Gustschin.

18) Missing break; in switch statement in bluetooth's
    hci_cmd_complete_evt().  Fix from Szymon Janc.

19) Fix queue programming in iwlwifi, from Johannes Berg.

20) Interrupt throttling defaults not being actually programmed into the
    hardware, fix from Jeff Kirsher and Ying Cai.

21) TLAN driver SKB encoding in descriptor busted on 64-bit, fix from
    Benjamin Poirier.

22) Fix blind status block RX producer pointer deref in TG3 driver, from
    Matt Carlson.

23) Promisc and multicast are busted on ehea, fixes from Thadeu Lima de
    Souza Cascardo.

24) Fix crashes in 6lowpan, from Alexander Smirnov.

25) tcp_complete_cwr() needs to be careful to not rewind the CWND to
    ssthresh if ssthresh has the "infinite" value.  Fix from Yuchung
    Cheng.

* git://git.kernel.org/pub/scm/linux/kernel/git/davem/net: (81 commits)
  sungem: Fix WakeOnLan
  tcp: change tcp_adv_win_scale and tcp_rmem[2]
  net: l2tp: unlock socket lock before returning from l2tp_ip_sendmsg
  drop_monitor: prevent init path from scheduling on the wrong cpu
  usbnet: fix failure handling in usbnet_probe
  usbnet: fix leak of transfer buffer of dev->interrupt
  ucc_geth: Add 16 bytes to max TX frame for VLANs
  net: ucc_geth, increase no. of HW RX descriptors
  netem: fix possible skb leak
  sky2: fix receive length error in mixed non-VLAN/VLAN traffic
  sky2: propogate rx hash when packet is copied
  net: fix two typos in skbuff.h
  cxgb3: Don't call cxgb_vlan_mode until q locks are initialized
  ixgbe: fix calling skb_put on nonlinear skb assertion bug
  ixgbe: Fix a memory leak in IEEE DCB
  igbvf: fix the bug when initializing the igbvf
  smsc75xx: enable mac to detect speed/duplex from phy
  smsc75xx: declare smsc75xx's MII as GMII capable
  smsc75xx: fix phy interrupt acknowledge
  smsc75xx: fix phy init reset loop
  ...
2012-05-03 17:10:39 -07:00
Paul E. McKenney
9dd8fb16c3 rcu: Make exit_rcu() more precise and consolidate
When running preemptible RCU, if a task exits in an RCU read-side
critical section having blocked within that same RCU read-side critical
section, the task must be removed from the list of tasks blocking a
grace period (perhaps the current grace period, perhaps the next grace
period, depending on timing).  The exit() path invokes exit_rcu() to
do this cleanup.

However, the current implementation of exit_rcu() needlessly does the
cleanup even if the task did not block within the current RCU read-side
critical section, which wastes time and needlessly increases the size
of the state space.  Fix this by only doing the cleanup if the current
task is actually on the list of tasks blocking some grace period.

While we are at it, consolidate the two identical exit_rcu() functions
into a single function.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Linus Torvalds <torvalds@linux-foundation.org>

Conflicts:

	kernel/rcupdate.c
2012-05-02 14:48:27 -07:00
Paul E. McKenney
616c310e83 rcu: Move PREEMPT_RCU preemption to switch_to() invocation
Currently, PREEMPT_RCU readers are enqueued upon entry to the scheduler.
This is inefficient because enqueuing is required only if there is a
context switch, and entry to the scheduler does not guarantee a context
switch.

The commit therefore moves the enqueuing to immediately precede the
call to switch_to() from the scheduler.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Tested-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-05-02 14:43:23 -07:00
John W. Linville
076e7779c0 Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/linville/wireless into for-davem 2012-05-01 14:14:05 -04:00
Eric Dumazet
d961949660 net: fix two typos in skbuff.h
fix kernel doc typos in function names

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-05-01 09:40:19 -04:00
Linus Torvalds
e7a7c9ab41 SCSI fixes on 20120430
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Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi

Pull SCSI fixes from James Bottomley:
 "This is a set of SAS and SATA fixes; there are one or two longstanding
  bug fixes, but most of this is regression fixes."

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  [SCSI] libfc: update mfs boundry checking
  [SCSI] Revert "[SCSI] libsas: fix sas port naming"
  [SCSI] libsas: fix false positive 'device attached' conditions
  [SCSI] libsas, libata: fix start of life for a sas ata_port
  [SCSI] libsas: fix ata_eh clobbering ex_phys via smp_ata_check_ready
  [SCSI] libsas: unify domain_device sas_rphy lifetimes
  [SCSI] libsas: fix sas_get_port_device regression
  [SCSI] libsas: fix sas_find_bcast_phy() in the presence of 'vacant' phys
  [SCSI] libsas: introduce sas_work to fix sas_drain_work vs sas_queue_work
  [SCSI] libata: Pass correct DMA device to scsi host
  [SCSI] scsi_lib: use correct DMA device in __scsi_alloc_queue
2012-04-30 15:33:50 -07:00
Matthew Garrett
41b3254c93 efi: Add new variable attributes
More recent versions of the UEFI spec have added new attributes for
variables. Add them.

Signed-off-by: Matthew Garrett <mjg@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-30 15:30:18 -07:00
H. Peter Anvin
f5c2347ee2 asm-generic: Use __BITS_PER_LONG in statfs.h
<asm-generic/statfs.h> is exported to userspace, so using
BITS_PER_LONG is invalid.  We need to use __BITS_PER_LONG instead.

This is kernel bugzilla 43165.

Reported-by: H.J. Lu <hjl.tools@gmail.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
Link: http://lkml.kernel.org/r/1335465916-16965-1-git-send-email-hpa@linux.intel.com
Acked-by: Arnd Bergmann <arnd@arndb.de>
Cc: <stable@vger.kernel.org>
2012-04-30 12:55:15 -07:00
Lai Jiangshan
931ea9d1a6 rcu: Implement per-domain single-threaded call_srcu() state machine
This commit implements an SRCU state machine in support of call_srcu().
The state machine is preemptible, light-weight, and single-threaded,
minimizing synchronization overhead.  In particular, there is no longer
any need for synchronize_srcu() to be guarded by a mutex.

Expedited processing is handled, at least in the absence of concurrent
grace-period operations on that same srcu_struct structure, by having
the synchronize_srcu_expedited() thread take on the role of the
workqueue thread for one iteration.

There is a reasonable probability that a given SRCU callback will
be invoked on the same CPU that registered it, however, there is no
guarantee.  Concurrent SRCU grace-period primitives can cause callbacks
to be executed elsewhere, even in absence of CPU-hotplug operations.

Callbacks execute in process context, but under the influence of
local_bh_disable(), so it is illegal to sleep in an SRCU callback
function.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-04-30 10:48:25 -07:00
Lai Jiangshan
966f58c2f6 rcu: Remove unused srcu_barrier()
The old srcu_barrier() macro is now unused.  This commit removes it so
that it may be used for the SRCU flavor of rcu_barrier(), which will in
turn be needed to allow the upcoming call_srcu() to be used from within
modules.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-04-30 10:48:23 -07:00
Lai Jiangshan
b52ce066c5 rcu: Implement a variant of Peter's SRCU algorithm
This commit implements a variant of Peter's algorithm, which may be found
at https://lkml.org/lkml/2012/2/1/119.

o	Make the checking lock-free to enable parallel checking.
	Parallel checking is required when (1) the original checking
	task is preempted for a long time, (2) sychronize_srcu_expedited()
	starts during an ongoing SRCU grace period, or (3) we wish to
	avoid acquiring a lock.

o	Since the checking is lock-free, we avoid a mutex in state machine
	for call_srcu().

o	Remove the SRCU_REF_MASK and remove the coupling with the flipping.
	This might allow us to remove the preempt_disable() in future
	versions, though such removal will need great care because it
	rescinds the one-old-reader-per-CPU guarantee.

o	Remove a smp_mb(), simplify the comments and make the smp_mb() pairs
	more intuitive.

Inspired-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-04-30 10:48:22 -07:00
Lai Jiangshan
440253c17f rcu: Increment upper bit only for srcu_read_lock()
The purpose of the upper bit of SRCU's per-CPU counters is to guarantee
that no reasonable series of srcu_read_lock() and srcu_read_unlock()
operations can return the value of the counter to its original value.
This guarantee is require only after the index has been switched to
the other set of counters, so at most one srcu_read_lock() can affect
a given CPU's counter.  The number of srcu_read_unlock() operations
on a given counter is limited to the number of tasks in the system,
which given the Linux kernel's current structure is limited to far less
than 2^30 on 32-bit systems and far less than 2^62 on 64-bit systems.
(Something about a limited number of bytes in the kernel's address space.)

Therefore, if srcu_read_lock() increments the upper bits, then
srcu_read_unlock() need not do so.  In this case, an srcu_read_lock() and
an srcu_read_unlock() will flip the lower bit of the upper field of the
counter.  An unreasonably large additional number of srcu_read_unlock()
operations would be required to return the counter to its initial value,
thus preserving the guarantee.

This commit takes this approach, which further allows it to shrink
the size of the upper field to one bit, making the number of
srcu_read_unlock() operations required to return the counter to its
initial value even more unreasonable than before.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-04-30 10:48:20 -07:00
Paul E. McKenney
cef50120b6 rcu: Direct algorithmic SRCU implementation
The current implementation of synchronize_srcu_expedited() can cause
severe OS jitter due to its use of synchronize_sched(), which in turn
invokes try_stop_cpus(), which causes each CPU to be sent an IPI.
This can result in severe performance degradation for real-time workloads
and especially for short-interation-length HPC workloads.  Furthermore,
because only one instance of try_stop_cpus() can be making forward progress
at a given time, only one instance of synchronize_srcu_expedited() can
make forward progress at a time, even if they are all operating on
distinct srcu_struct structures.

This commit, inspired by an earlier implementation by Peter Zijlstra
(https://lkml.org/lkml/2012/1/31/211) and by further offline discussions,
takes a strictly algorithmic bits-in-memory approach.  This has the
disadvantage of requiring one explicit memory-barrier instruction in
each of srcu_read_lock() and srcu_read_unlock(), but on the other hand
completely dispenses with OS jitter and furthermore allows SRCU to be
used freely by CPUs that RCU believes to be idle or offline.

The update-side implementation handles the single read-side memory
barrier by rechecking the per-CPU counters after summing them and
by running through the update-side state machine twice.

This implementation has passed moderate rcutorture testing on both
x86 and Power.  Also updated to use this_cpu_ptr() instead of per_cpu_ptr(),
as suggested by Peter Zijlstra.

Reported-by: Peter Zijlstra <peterz@infradead.org>
Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Reviewed-by: Lai Jiangshan <laijs@cn.fujitsu.com>
2012-04-30 10:48:19 -07:00
Eric Dumazet
518fbf9cdf net: fix sk_sockets_allocated_read_positive
Denys Fedoryshchenko reported frequent crashes on a proxy server and kindly
provided a lockdep report that explains it all :

  [  762.903868]
  [  762.903880] =================================
  [  762.903890] [ INFO: inconsistent lock state ]
  [  762.903903] 3.3.4-build-0061 #8 Not tainted
  [  762.904133] ---------------------------------
  [  762.904344] inconsistent {IN-SOFTIRQ-W} -> {SOFTIRQ-ON-W} usage.
  [  762.904542] squid/1603 [HC0[0]:SC0[0]:HE1:SE1] takes:
  [  762.904542]  (key#3){+.?...}, at: [<c0232cc4>]
__percpu_counter_sum+0xd/0x58
  [  762.904542] {IN-SOFTIRQ-W} state was registered at:
  [  762.904542]   [<c0158b84>] __lock_acquire+0x284/0xc26
  [  762.904542]   [<c01598e8>] lock_acquire+0x71/0x85
  [  762.904542]   [<c0349765>] _raw_spin_lock+0x33/0x40
  [  762.904542]   [<c0232c93>] __percpu_counter_add+0x58/0x7c
  [  762.904542]   [<c02cfde1>] sk_clone_lock+0x1e5/0x200
  [  762.904542]   [<c0303ee4>] inet_csk_clone_lock+0xe/0x78
  [  762.904542]   [<c0315778>] tcp_create_openreq_child+0x1b/0x404
  [  762.904542]   [<c031339c>] tcp_v4_syn_recv_sock+0x32/0x1c1
  [  762.904542]   [<c031615a>] tcp_check_req+0x1fd/0x2d7
  [  762.904542]   [<c0313f77>] tcp_v4_do_rcv+0xab/0x194
  [  762.904542]   [<c03153bb>] tcp_v4_rcv+0x3b3/0x5cc
  [  762.904542]   [<c02fc0c4>] ip_local_deliver_finish+0x13a/0x1e9
  [  762.904542]   [<c02fc539>] NF_HOOK.clone.11+0x46/0x4d
  [  762.904542]   [<c02fc652>] ip_local_deliver+0x41/0x45
  [  762.904542]   [<c02fc4d1>] ip_rcv_finish+0x31a/0x33c
  [  762.904542]   [<c02fc539>] NF_HOOK.clone.11+0x46/0x4d
  [  762.904542]   [<c02fc857>] ip_rcv+0x201/0x23e
  [  762.904542]   [<c02daa3a>] __netif_receive_skb+0x319/0x368
  [  762.904542]   [<c02dac07>] netif_receive_skb+0x4e/0x7d
  [  762.904542]   [<c02dacf6>] napi_skb_finish+0x1e/0x34
  [  762.904542]   [<c02db122>] napi_gro_receive+0x20/0x24
  [  762.904542]   [<f85d1743>] e1000_receive_skb+0x3f/0x45 [e1000e]
  [  762.904542]   [<f85d3464>] e1000_clean_rx_irq+0x1f9/0x284 [e1000e]
  [  762.904542]   [<f85d3926>] e1000_clean+0x62/0x1f4 [e1000e]
  [  762.904542]   [<c02db228>] net_rx_action+0x90/0x160
  [  762.904542]   [<c012a445>] __do_softirq+0x7b/0x118
  [  762.904542] irq event stamp: 156915469
  [  762.904542] hardirqs last  enabled at (156915469): [<c019b4f4>]
__slab_alloc.clone.58.clone.63+0xc4/0x2de
  [  762.904542] hardirqs last disabled at (156915468): [<c019b452>]
__slab_alloc.clone.58.clone.63+0x22/0x2de
  [  762.904542] softirqs last  enabled at (156915466): [<c02ce677>]
lock_sock_nested+0x64/0x6c
  [  762.904542] softirqs last disabled at (156915464): [<c0349914>]
_raw_spin_lock_bh+0xe/0x45
  [  762.904542]
  [  762.904542] other info that might help us debug this:
  [  762.904542]  Possible unsafe locking scenario:
  [  762.904542]
  [  762.904542]        CPU0
  [  762.904542]        ----
  [  762.904542]   lock(key#3);
  [  762.904542]   <Interrupt>
  [  762.904542]     lock(key#3);
  [  762.904542]
  [  762.904542]  *** DEADLOCK ***
  [  762.904542]
  [  762.904542] 1 lock held by squid/1603:
  [  762.904542]  #0:  (sk_lock-AF_INET){+.+.+.}, at: [<c03055c0>]
lock_sock+0xa/0xc
  [  762.904542]
  [  762.904542] stack backtrace:
  [  762.904542] Pid: 1603, comm: squid Not tainted 3.3.4-build-0061 #8
  [  762.904542] Call Trace:
  [  762.904542]  [<c0347b73>] ? printk+0x18/0x1d
  [  762.904542]  [<c015873a>] valid_state+0x1f6/0x201
  [  762.904542]  [<c0158816>] mark_lock+0xd1/0x1bb
  [  762.904542]  [<c015876b>] ? mark_lock+0x26/0x1bb
  [  762.904542]  [<c015805d>] ? check_usage_forwards+0x77/0x77
  [  762.904542]  [<c0158bf8>] __lock_acquire+0x2f8/0xc26
  [  762.904542]  [<c0159b8e>] ? mark_held_locks+0x5d/0x7b
  [  762.904542]  [<c0159cf6>] ? trace_hardirqs_on+0xb/0xd
  [  762.904542]  [<c0158dd4>] ? __lock_acquire+0x4d4/0xc26
  [  762.904542]  [<c01598e8>] lock_acquire+0x71/0x85
  [  762.904542]  [<c0232cc4>] ? __percpu_counter_sum+0xd/0x58
  [  762.904542]  [<c0349765>] _raw_spin_lock+0x33/0x40
  [  762.904542]  [<c0232cc4>] ? __percpu_counter_sum+0xd/0x58
  [  762.904542]  [<c0232cc4>] __percpu_counter_sum+0xd/0x58
  [  762.904542]  [<c02cebc4>] __sk_mem_schedule+0xdd/0x1c7
  [  762.904542]  [<c02d178d>] ? __alloc_skb+0x76/0x100
  [  762.904542]  [<c0305e8e>] sk_wmem_schedule+0x21/0x2d
  [  762.904542]  [<c0306370>] sk_stream_alloc_skb+0x42/0xaa
  [  762.904542]  [<c0306567>] tcp_sendmsg+0x18f/0x68b
  [  762.904542]  [<c031f3dc>] ? ip_fast_csum+0x30/0x30
  [  762.904542]  [<c0320193>] inet_sendmsg+0x53/0x5a
  [  762.904542]  [<c02cb633>] sock_aio_write+0xd2/0xda
  [  762.904542]  [<c015876b>] ? mark_lock+0x26/0x1bb
  [  762.904542]  [<c01a1017>] do_sync_write+0x9f/0xd9
  [  762.904542]  [<c01a2111>] ? file_free_rcu+0x2f/0x2f
  [  762.904542]  [<c01a17a1>] vfs_write+0x8f/0xab
  [  762.904542]  [<c01a284d>] ? fget_light+0x75/0x7c
  [  762.904542]  [<c01a1900>] sys_write+0x3d/0x5e
  [  762.904542]  [<c0349ec9>] syscall_call+0x7/0xb
  [  762.904542]  [<c0340000>] ? rp_sidt+0x41/0x83

Bug is that sk_sockets_allocated_read_positive() calls
percpu_counter_sum_positive() without BH being disabled.

This bug was added in commit 180d8cd942
(foundations of per-cgroup memory pressure controlling.), since previous
code was using percpu_counter_read_positive() which is IRQ safe.

In __sk_mem_schedule() we dont need the precise count of allocated
sockets and can revert to previous behavior.

Reported-by: Denys Fedoryshchenko <denys@visp.net.lb>
Sined-off-by: Eric Dumazet <edumazet@google.com>
Cc: Glauber Costa <glommer@parallels.com>
Acked-by: Neal Cardwell <ncardwell@google.com>

Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-30 13:37:59 -04:00
David S. Miller
5414fc12e3 Merge branch 'master' of git://1984.lsi.us.es/net 2012-04-30 13:23:22 -04:00
Hans Schillstrom
8537de8a7a ipvs: kernel oops - do_ip_vs_get_ctl
Change order of init so netns init is ready
when register ioctl and netlink.

Ver2
	Whitespace fixes and __init added.

Reported-by: "Ryan O'Hara" <rohara@redhat.com>
Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Jesper Dangaard Brouer <brouer@redhat.com>
Signed-off-by: Simon Horman <horms@verge.net.au>
2012-04-30 10:40:35 +02:00
Hans Schillstrom
582b8e3ead ipvs: take care of return value from protocol init_netns
ip_vs_create_timeout_table() can return NULL
All functions protocol init_netns is affected of this patch.

Signed-off-by: Hans Schillstrom <hans.schillstrom@ericsson.com>
Acked-by: Julian Anastasov <ja@ssi.bg>
Signed-off-by: Simon Horman <horms@verge.net.au>
2012-04-30 10:40:35 +02:00
Linus Torvalds
9883035ae7 pipes: add a "packetized pipe" mode for writing
The actual internal pipe implementation is already really about
individual packets (called "pipe buffers"), and this simply exposes that
as a special packetized mode.

When we are in the packetized mode (marked by O_DIRECT as suggested by
Alan Cox), a write() on a pipe will not merge the new data with previous
writes, so each write will get a pipe buffer of its own.  The pipe
buffer is then marked with the PIPE_BUF_FLAG_PACKET flag, which in turn
will tell the reader side to break the read at that boundary (and throw
away any partial packet contents that do not fit in the read buffer).

End result: as long as you do writes less than PIPE_BUF in size (so that
the pipe doesn't have to split them up), you can now treat the pipe as a
packet interface, where each read() system call will read one packet at
a time.  You can just use a sufficiently big read buffer (PIPE_BUF is
sufficient, since bigger than that doesn't guarantee atomicity anyway),
and the return value of the read() will naturally give you the size of
the packet.

NOTE! We do not support zero-sized packets, and zero-sized reads and
writes to a pipe continue to be no-ops.  Also note that big packets will
currently be split at write time, but that the size at which that
happens is not really specified (except that it's bigger than PIPE_BUF).
Currently that limit is the system page size, but we might want to
explicitly support bigger packets some day.

The main user for this is going to be the autofs packet interface,
allowing us to stop having to care so deeply about exact packet sizes
(which have had bugs with 32/64-bit compatibility modes).  But user
space can create packetized pipes with "pipe2(fd, O_DIRECT)", which will
fail with an EINVAL on kernels that do not support this interface.

Tested-by: Michael Tokarev <mjt@tls.msk.ru>
Cc: Alan Cox <alan@lxorguk.ukuu.org.uk>
Cc: David Miller <davem@davemloft.net>
Cc: Ian Kent <raven@themaw.net>
Cc: Thomas Meyer <thomas@m3y3r.de>
Cc: stable@kernel.org  # needed for systemd/autofs interaction fix
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-29 13:12:42 -07:00
Linus Torvalds
8d7d1adcd7 USB fixes for 3.4-rc5
Here are a number of small USB fixes for 3.4-rc5.
 
 Nothing major, as before, some USB gadget fixes.  There's a crash fix
 for a number of ASUS laptops on resume that had been reported by a
 number of different people.  We think the fix might also pertain to
 other machines, as this was a BIOS bug, and they seem to travel to
 different models and manufacturers quite easily.  Other than that, some
 other reported problems fixed as well.
 
 Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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Merge tag 'usb-3.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb

Pull USB fixes from Greg Kroah-Hartman:
 "Here are a number of small USB fixes for 3.4-rc5.

  Nothing major, as before, some USB gadget fixes.  There's a crash fix
  for a number of ASUS laptops on resume that had been reported by a
  number of different people.  We think the fix might also pertain to
  other machines, as this was a BIOS bug, and they seem to travel to
  different models and manufacturers quite easily.  Other than that,
  some other reported problems fixed as well."

* tag 'usb-3.4-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb:
  usb: gadget: udc-core: fix incompatibility with dummy-hcd
  usb: gadget: udc-core: fix wrong call order
  USB: cdc-wdm: fix race leading leading to memory corruption
  USB: EHCI: fix crash during suspend on ASUS computers
  usb gadget: uvc: uvc_request_data::length field must be signed
  usb: gadget: dummy: do not call pullup() on udc_stop()
  usb: musb: davinci.c: add missing unregister
  usb: musb: drop __deprecated flag
  USB: gadget: storage gadgets send wrong error code for unknown commands
  usb: otg: gpio_vbus: Add otg transceiver events and notifiers
2012-04-29 12:17:54 -07:00
Linus Torvalds
b990f9b3cb ARM: SoC fixes for 3.4-rc
Nothing controversial, just another batch of fixes:
 
 - Samsung/exynos fixes for more merge window fallout: build errors and
   warnings mostly, but also some clock/device setup issues on exynos4/5
 - PXA bug and warning fixes related to gpio and pinmux
 - IRQ domain conversion bugfixes for U300 and MSM
 - A regulator setup fix for U300
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Merge tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc

Pull ARM SoC fixes from Olof Johansson:
 "Nothing controversial, just another batch of fixes:

   - Samsung/exynos fixes for more merge window fallout: build errors
     and warnings mostly, but also some clock/device setup issues on
     exynos4/5
   - PXA bug and warning fixes related to gpio and pinmux
   - IRQ domain conversion bugfixes for U300 and MSM
   - A regulator setup fix for U300"

* tag 'fixes-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/arm/arm-soc:
  ARM: PXA2xx: MFP: fix potential direction bug
  ARM: PXA2xx: MFP: fix bug with MFP_LPM_KEEP_OUTPUT
  arm/sa1100: fix sa1100-rtc memory resource
  ARM: pxa: fix gpio wakeup setting
  ARM: SAMSUNG: add missing MMC_CAP2_BROKEN_VOLTAGE capability
  ARM: EXYNOS: Fix compilation error when CONFIG_OF is not defined
  ARM: EXYNOS: Fix resource on dev-dwmci.c
  ARM: S3C24XX: Fix build warning for S3C2410_PM
  ARM: mini2440_defconfig: Fix build error
  ARM: msm: Fix gic irqdomain support
  ARM: EXYNOS: Fix incorrect initialization of GIC
  ARM: EXYNOS: use 'exynos4-sdhci' as device name for sdhci controllers
  ARM: u300: bump all IRQ numbers by one
  ARM: ux300: Fix unimplementable regulation constraints
2012-04-28 09:28:43 -07:00
Linus Torvalds
84c6a81bc6 Miscellaneous SPI device driver bug fixes for v3.4
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Merge tag 'spi-for-linus' of git://git.secretlab.ca/git/linux-2.6

Pull misc SPI device driver bug fixes from Grant Likely.

* tag 'spi-for-linus' of git://git.secretlab.ca/git/linux-2.6:
  spi/spi-bfin5xx: Fix flush of last bit after each spi transfer
  spi/spi-bfin5xx: fix reversed if condition in interrupt mode
  spi/spi_bfin_sport: drop bits_per_word from client data
  spi/bfin_spi: drop bits_per_word from client data
  spi/spi-bfin-sport: move word length setup to transfer handler
  spi/bfin5xx: rename config macro name for bfin5xx spi controller driver
  spi/pl022: Allow request for higher frequency than maximum possible
  spi/bcm63xx: set master driver mode_bits.
  spi/bcm63xx: don't use the stopping state
  spi/bcm63xx: convert to the pump message infrastructure
  spi/spi-ep93xx.c: use dma_transfer_direction instead of dma_data_direction
  spi: fix spi.h kernel-doc warning
  spi/pl022: Fix calculate_effective_freq()
  spi/pl022: Fix range checking for bits per word
2012-04-27 19:52:30 -07:00
John W. Linville
4dcc0637fc Merge branch 'for-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/bluetooth/bluetooth 2012-04-27 15:16:43 -04:00
Randy Dunlap
dbabe0d659 spi: fix spi.h kernel-doc warning
Fix kernel-doc warning in spi.h (copy/paste):

Warning(include/linux/spi/spi.h:365): No description found for parameter 'unprepare_transfer_hardware'

Signed-off-by: Randy Dunlap <rdunlap@xenotime.net>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
2012-04-27 11:03:38 -06:00
Robert Jarzmik
b95ace54a2 ARM: pxa: fix gpio wakeup setting
In 3.3, gpio wakeup setting was broken. The call
enable_irq_wake() didn't set up the PXA gpio registers
(PWER, ...) anymore.

Fix it at least for pxa27x. The driver doesn't seem to be
used in pxa25x (weird ...), and the fix doesn't extend to
pxa3xx and pxa95x (which don't have a gpio_set_wake()
available).

Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr>
Signed-off-by: Haojian Zhuang <haojian.zhuang@gmail.com>
2012-04-27 10:46:45 +08:00
Linus Torvalds
110a5c8b38 Merge branch 'akpm' (Andrew's patch-bomb)
Merge fixes from Andrew Morton:
 "13 fixes.  The acerhdf patches aren't (really) fixes.  But they've
  been stuck in my tree for up to two years, sent to Matthew multiple
  times and the developers are unhappy."

* emailed from Andrew Morton <akpm@linux-foundation.org>: (13 patches)
  mm: fix NULL ptr dereference in move_pages
  mm: fix NULL ptr dereference in migrate_pages
  revert "proc: clear_refs: do not clear reserved pages"
  drivers/rtc/rtc-ds1307.c: fix BUG shown with lock debugging enabled
  arch/arm/mach-ux500/mbox-db5500.c: world-writable sysfs fifo file
  hugetlbfs: lockdep annotate root inode properly
  acerhdf: lowered default temp fanon/fanoff values
  acerhdf: add support for new hardware
  acerhdf: add support for Aspire 1410 BIOS v1.3314
  fs/buffer.c: remove BUG() in possible but rare condition
  mm: fix up the vmscan stat in vmstat
  epoll: clear the tfile_check_list on -ELOOP
  mm/hugetlb: fix warning in alloc_huge_page/dequeue_huge_page_vma
2012-04-26 15:24:45 -07:00
Linus Torvalds
2300fd67b4 NFS client bugfixes for Linux 3.4
Highlights include:
 - Fix NFSv4 infinite loops on open(O_TRUNC)
 - Fix an Oops and an infinite loop in the NFSv4 flock code
 - Don't register the PipeFS filesystem until it has been set up
 - Fix an Oops in nfs_try_to_update_request
 - Don't reuse NFSv4 open owners: fixes a bad sequence id storm.
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Merge tag 'nfs-for-3.4-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs

Pull NFS client bugfixes from Trond Myklebust:
 - Fix NFSv4 infinite loops on open(O_TRUNC)
 - Fix an Oops and an infinite loop in the NFSv4 flock code
 - Don't register the PipeFS filesystem until it has been set up
 - Fix an Oops in nfs_try_to_update_request
 - Don't reuse NFSv4 open owners: fixes a bad sequence id storm.

* tag 'nfs-for-3.4-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs:
  NFSv4: Keep dropped state owners on the LRU list for a while
  NFSv4: Ensure that we don't drop a state owner more than once
  NFSv4: Ensure we do not reuse open owner names
  nfs: Enclose hostname in brackets when needed in nfs_do_root_mount
  NFS: put open context on error in nfs_flush_multi
  NFS: put open context on error in nfs_pagein_multi
  NFSv4: Fix open(O_TRUNC) and ftruncate() error handling
  NFSv4: Ensure that we check lock exclusive/shared type against open modes
  NFSv4: Ensure that the LOCK code sets exception->inode
  NFS: check for req==NULL in nfs_try_to_update_request cleanup
  SUNRPC: register PipeFS file system after pernet sybsystem
2012-04-25 21:38:44 -07:00
Linus Torvalds
86ec090e58 Merge branch 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from H. Peter Anvin.

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x32, siginfo: Provide proper overrides for x32 siginfo_t
  asm-generic: Allow overriding clock_t and add attributes to siginfo_t
  x32: Check __ILP32__ instead of __LP64__ for x32
  x86, acpi: Call acpi_enter_sleep_state via an asmlinkage C function from assembler
  ACPI: Convert wake_sleep_flags to a value instead of function
  x86, apic: APIC code touches invalid MSR on P5 class machines
  i387: ptrace breaks the lazy-fpu-restore logic
  x86/platform: Remove incorrect error message in x86_default_fixup_cpu_id()
  x86, efi: Add dedicated EFI stub entry point
  x86/amd: Remove broken links from comment and kernel message
  x86, microcode: Ensure that module is only loaded on supported AMD CPUs
  x86, microcode: Fix sysfs warning during module unload on unsupported CPUs
2012-04-25 21:29:26 -07:00
Ying Han
904249aa68 mm: fix up the vmscan stat in vmstat
The "pgsteal" stat is confusing because it counts both direct reclaim as
well as background reclaim.  However, we have "kswapd_steal" which also
counts background reclaim value.

This patch fixes it and also makes it match the existng "pgscan_" stats.

Test:
pgsteal_kswapd_dma32 447623
pgsteal_kswapd_normal 42272677
pgsteal_kswapd_movable 0
pgsteal_direct_dma32 2801
pgsteal_direct_normal 44353270
pgsteal_direct_movable 0

Signed-off-by: Ying Han <yinghan@google.com>
Reviewed-by: Rik van Riel <riel@redhat.com>
Acked-by: Christoph Lameter <cl@linux.com>
Cc: Johannes Weiner <hannes@cmpxchg.org>
Cc: Michal Hocko <mhocko@suse.cz>
Cc: Mel Gorman <mel@csn.ul.ie>
Acked-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>
Cc: Hillf Danton <dhillf@gmail.com>
Cc: Hugh Dickins <hughd@google.com>
Cc: Dan Magenheimer <dan.magenheimer@oracle.com>
Reviewed-by: Minchan Kim <minchan@kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2012-04-25 21:26:33 -07:00
Ingo Molnar
cd32b1616b A small L3 cache index disable fix from Srivatsa Bhat which unifies the
way the code checks for already disabled indices.
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Merge tag 'l3-fix-for-3.5' of git://git.kernel.org/pub/scm/linux/kernel/git/bp/bp into x86/urgent

A small L3 cache index disable fix from Srivatsa Bhat which unifies the
way the code checks for already disabled indices.

( Pulling it into v3.4 despite the v3.5 tag - the fix is small and we better
  keep the same code across kernel versions for such user facing interfaces. )

Signed-off-by: Ingo Molnar <mingo@kernel.org>
2012-04-25 12:24:16 +02:00
Paul E. McKenney
2fdbb31b66 rcu: Add RCU_FAST_NO_HZ tracing for idle exit
Traces of rcu_prep_idle events can be confusing because
rcu_cleanup_after_idle() does no tracing.  This commit therefore adds
this tracing.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-04-24 20:55:19 -07:00
Paul E. McKenney
6d8133919b rcu: Document why rcu_blocking_is_gp() is safe
The rcu_blocking_is_gp() function tests to see if there is only one
online CPU, and if so, synchronize_sched() and friends become no-ops.
However, for larger systems, num_online_cpus() scans a large vector,
and might be preempted while doing so.  While preempted, any number
of CPUs might come online and go offline, potentially resulting in
num_online_cpus() returning 1 when there never had only been one
CPU online.  This could result in a too-short RCU grace period, which
could in turn result in total failure, except that the only way that
the grace period is too short is if there is an RCU read-side critical
section spanning it.  For RCU-sched and RCU-bh (which are the only
cases using rcu_blocking_is_gp()), RCU read-side critical sections
have either preemption or bh disabled, which prevents CPUs from going
offline.  This in turn prevents actual failures from occurring.

This commit therefore adds a large block comment to rcu_blocking_is_gp()
documenting why it is safe.  This commit also moves rcu_blocking_is_gp()
into kernel/rcutree.c, which should help prevent unwary developers from
mistaking it for a generally useful function.

Signed-off-by: Paul E. McKenney <paul.mckenney@linaro.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-04-24 20:54:53 -07:00
Jan Engelhardt
d8169d4c36 rcu: Make __kfree_rcu() less dependent on compiler choices
Currently, __kfree_rcu() is implemented as an inline function, and
contains a BUILD_BUG_ON() that malfunctions if __kfree_rcu() is compiled
as an out-of-line function.  Unfortunately, there are compiler settings
(e.g., -O0) that can result in __kfree_rcu() being compiled out of line,
resulting in annoying build breakage.  This commit therefore converts
both __kfree_rcu() and __is_kfree_rcu_offset() from inline functions to
macros to prevent such misbehavior on the part of the compiler.

Signed-off-by: Jan Engelhardt <jengelh@medozas.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>
2012-04-24 20:54:51 -07:00
Michel Machado
f88022a4f6 rcu: Replace list_first_entry_rcu() with list_first_or_null_rcu()
The list_first_entry_rcu() macro is inherently unsafe because it cannot
be applied to an empty list.  But because RCU readers do not exclude
updaters, a list might become empty between the time that list_empty()
claimed it was non-empty and the time that list_first_entry_rcu() is
invoked.  Therefore, the list_empty() test cannot be separated from the
list_first_entry_rcu() call.  This commit therefore combines these to
macros to create a new list_first_or_null_rcu() macro that replaces
the old (and unsafe) list_first_entry_rcu() macro.

This patch incorporates Paul's review comments on the previous version of
this patch available here:

https://lkml.org/lkml/2012/4/2/536

This patch cannot break any upstream code because list_first_entry_rcu()
is not being used anywhere in the kernel (tested with grep(1)), and any
external code using it is probably broken as a result of using it.

Signed-off-by: Michel Machado <michel@digirati.com.br>
CC: "Paul E. McKenney" <paulmck@linux.vnet.ibm.com>
CC: Dipankar Sarma <dipankar@in.ibm.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-04-24 20:54:49 -07:00
Dave Jones
559f9badd1 rcu: List-debug variants of rcu list routines.
* Make __list_add_rcu check the next->prev and prev->next pointers
  just like __list_add does.
* Make list_del_rcu use __list_del_entry, which does the same checking
  at deletion time.

Has been running for a week here without anything being tripped up,
but it seems worth adding for completeness just in case something
ever does corrupt those lists.

Signed-off-by: Dave Jones <davej@redhat.com>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
2012-04-24 20:54:49 -07:00
Alan Stern
151b612847 USB: EHCI: fix crash during suspend on ASUS computers
This patch (as1545) fixes a problem affecting several ASUS computers:
The machine crashes or corrupts memory when going into suspend if the
ehci-hcd driver is bound to any controllers.  Users have been forced
to unbind or unload ehci-hcd before putting their systems to sleep.

After extensive testing, it was determined that the machines don't
like going into suspend when any EHCI controllers are in the PCI D3
power state.  Presumably this is a firmware bug, but there's nothing
we can do about it except to avoid putting the controllers in D3
during system sleep.

The patch adds a new flag to indicate whether the problem is present,
and avoids changing the controller's power state if the flag is set.
Runtime suspend is unaffected; this matters only for system suspend.
However as a side effect, the controller will not respond to remote
wakeup requests while the system is asleep.  Hence USB wakeup is not
functional -- but of course, this is already true in the current state
of affairs.

This fixes Bugzilla #42728.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Tested-by: Steven Rostedt <rostedt@goodmis.org>
Tested-by: Andrey Rahmatullin <wrar@wrar.name>
Tested-by: Oleksij Rempel (fishor) <bug-track@fisher-privat.net>
Cc: stable <stable@vger.kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2012-04-24 13:55:43 -07:00
Linus Torvalds
423b40e194 HSI fixes and ABI documentation for 3.4
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Merge tag 'hsi_fixes_for_3.4' of git://gitorious.org/kernel-hsi/kernel-hsi

Pull HSI fixes and ABI documentation from Carlos Chinea

* tag 'hsi_fixes_for_3.4' of git://gitorious.org/kernel-hsi/kernel-hsi:
  HSI: Add HSI ABI documentation
  HSI: hsi_char: Remove max_data_size from sysfs
  HSI: hsi: Rework hsi_event interface
  HSI: hsi: Remove controllers and ports from the bus
  HSI: hsi: Fix error path cleanup on client registration
  HSI: hsi: Rework hsi_controller release
2012-04-24 08:20:28 -07:00
Peter Huang (Peng)
a881e963c7 set fake_rtable's dst to NULL to avoid kernel Oops
bridge: set fake_rtable's dst to NULL to avoid kernel Oops

when bridge is deleted before tap/vif device's delete, kernel may
encounter an oops because of NULL reference to fake_rtable's dst.
Set fake_rtable's dst to NULL before sending packets out can solve
this problem.

v4 reformat, change br_drop_fake_rtable(skb) to {}

v3 enrich commit header

v2 introducing new flag DST_FAKE_RTABLE to dst_entry struct.

[ Use "do { } while (0)" for nop br_drop_fake_rtable()
  implementation -DaveM ]

Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: Peter Huang <peter.huangpeng@huawei.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
2012-04-24 00:16:24 -04:00
H. Peter Anvin
d643bdca8a asm-generic: Allow overriding clock_t and add attributes to siginfo_t
For the particular issue of x32, which shares code with i386 in the
handling of compat_siginfo_t, the use of a 64-bit clock_t bumps the
sigchld structure out of alignment, which triggers a messy cascade of
padding.

This was already handled on the kernel compat side, but it needs
handling on the user space side, which uses the generic header.  To
make that possible:

1. Allow __kernel_clock_t to be overridden in struct siginfo;
2. Allow there to be attributes added to struct siginfo.

Reported-by: H.J. Lu <hjl.rools@gmail.com>
Cc: Bruce J. Beare <bruce.j.beare@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Link: http://lkml.kernel.org/r/CAMe9rOqF6Kh6-NK7oP0Fpzkd4SBAWU%2BG53hwBbSD4iA2UzyxuA@mail.gmail.com
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>
2012-04-23 16:29:18 -07:00