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2015-05-08locking/pvqspinlock, x86: Enable PV qspinlock for KVMWaiman Long2-1/+44
This patch adds the necessary KVM specific code to allow KVM to support the CPU halting and kicking operations needed by the queue spinlock PV code. Signed-off-by: Waiman Long <Waiman.Long@hp.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Daniel J Blueman <daniel@numascale.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Douglas Hatch <doug.hatch@hp.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <paolo.bonzini@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1429901803-29771-11-git-send-email-Waiman.Long@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08locking/pvqspinlock, x86: Implement the paravirt qspinlock call patchingPeter Zijlstra (Intel)8-12/+128
We use the regular paravirt call patching to switch between: native_queued_spin_lock_slowpath() __pv_queued_spin_lock_slowpath() native_queued_spin_unlock() __pv_queued_spin_unlock() We use a callee saved call for the unlock function which reduces the i-cache footprint and allows 'inlining' of SPIN_UNLOCK functions again. We further optimize the unlock path by patching the direct call with a "movb $0,%arg1" if we are indeed using the native unlock code. This makes the unlock code almost as fast as the !PARAVIRT case. This significantly lowers the overhead of having CONFIG_PARAVIRT_SPINLOCKS enabled, even for native code. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Waiman Long <Waiman.Long@hp.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Daniel J Blueman <daniel@numascale.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Douglas Hatch <doug.hatch@hp.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <paolo.bonzini@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1429901803-29771-10-git-send-email-Waiman.Long@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08locking/pvqspinlock: Implement simple paravirt support for the qspinlockWaiman Long2-1/+392
Provide a separate (second) version of the spin_lock_slowpath for paravirt along with a special unlock path. The second slowpath is generated by adding a few pv hooks to the normal slowpath, but where those will compile away for the native case, they expand into special wait/wake code for the pv version. The actual MCS queue can use extra storage in the mcs_nodes[] array to keep track of state and therefore uses directed wakeups. The head contender has no such storage directly visible to the unlocker. So the unlocker searches a hash table with open addressing using a simple binary Galois linear feedback shift register. Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Waiman Long <Waiman.Long@hp.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Daniel J Blueman <daniel@numascale.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Douglas Hatch <doug.hatch@hp.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <paolo.bonzini@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1429901803-29771-9-git-send-email-Waiman.Long@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08locking/qspinlock: Revert to test-and-set on hypervisorsPeter Zijlstra (Intel)3-0/+24
When we detect a hypervisor (!paravirt, see qspinlock paravirt support patches), revert to a simple test-and-set lock to avoid the horrors of queue preemption. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Waiman Long <Waiman.Long@hp.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Daniel J Blueman <daniel@numascale.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Douglas Hatch <doug.hatch@hp.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <paolo.bonzini@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1429901803-29771-8-git-send-email-Waiman.Long@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08locking/qspinlock: Use a simple write to grab the lockWaiman Long1-16/+50
Currently, atomic_cmpxchg() is used to get the lock. However, this is not really necessary if there is more than one task in the queue and the queue head don't need to reset the tail code. For that case, a simple write to set the lock bit is enough as the queue head will be the only one eligible to get the lock as long as it checks that both the lock and pending bits are not set. The current pending bit waiting code will ensure that the bit will not be set as soon as the tail code in the lock is set. With that change, the are some slight improvement in the performance of the queued spinlock in the 5M loop micro-benchmark run on a 4-socket Westere-EX machine as shown in the tables below. [Standalone/Embedded - same node] # of tasks Before patch After patch %Change ---------- ----------- ---------- ------- 3 2324/2321 2248/2265 -3%/-2% 4 2890/2896 2819/2831 -2%/-2% 5 3611/3595 3522/3512 -2%/-2% 6 4281/4276 4173/4160 -3%/-3% 7 5018/5001 4875/4861 -3%/-3% 8 5759/5750 5563/5568 -3%/-3% [Standalone/Embedded - different nodes] # of tasks Before patch After patch %Change ---------- ----------- ---------- ------- 3 12242/12237 12087/12093 -1%/-1% 4 10688/10696 10507/10521 -2%/-2% It was also found that this change produced a much bigger performance improvement in the newer IvyBridge-EX chip and was essentially to close the performance gap between the ticket spinlock and queued spinlock. The disk workload of the AIM7 benchmark was run on a 4-socket Westmere-EX machine with both ext4 and xfs RAM disks at 3000 users on a 3.14 based kernel. The results of the test runs were: AIM7 XFS Disk Test kernel JPM Real Time Sys Time Usr Time ----- --- --------- -------- -------- ticketlock 5678233 3.17 96.61 5.81 qspinlock 5750799 3.13 94.83 5.97 AIM7 EXT4 Disk Test kernel JPM Real Time Sys Time Usr Time ----- --- --------- -------- -------- ticketlock 1114551 16.15 509.72 7.11 qspinlock 2184466 8.24 232.99 6.01 The ext4 filesystem run had a much higher spinlock contention than the xfs filesystem run. The "ebizzy -m" test was also run with the following results: kernel records/s Real Time Sys Time Usr Time ----- --------- --------- -------- -------- ticketlock 2075 10.00 216.35 3.49 qspinlock 3023 10.00 198.20 4.80 Signed-off-by: Waiman Long <Waiman.Long@hp.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Daniel J Blueman <daniel@numascale.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Douglas Hatch <doug.hatch@hp.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <paolo.bonzini@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1429901803-29771-7-git-send-email-Waiman.Long@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08locking/qspinlock: Optimize for smaller NR_CPUSPeter Zijlstra (Intel)2-1/+81
When we allow for a max NR_CPUS < 2^14 we can optimize the pending wait-acquire and the xchg_tail() operations. By growing the pending bit to a byte, we reduce the tail to 16bit. This means we can use xchg16 for the tail part and do away with all the repeated compxchg() operations. This in turn allows us to unconditionally acquire; the locked state as observed by the wait loops cannot change. And because both locked and pending are now a full byte we can use simple stores for the state transition, obviating one atomic operation entirely. This optimization is needed to make the qspinlock achieve performance parity with ticket spinlock at light load. All this is horribly broken on Alpha pre EV56 (and any other arch that cannot do single-copy atomic byte stores). Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Waiman Long <Waiman.Long@hp.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Daniel J Blueman <daniel@numascale.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Douglas Hatch <doug.hatch@hp.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <paolo.bonzini@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1429901803-29771-6-git-send-email-Waiman.Long@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08locking/qspinlock: Extract out code snippets for the next patchWaiman Long2-31/+50
This is a preparatory patch that extracts out the following 2 code snippets to prepare for the next performance optimization patch. 1) the logic for the exchange of new and previous tail code words into a new xchg_tail() function. 2) the logic for clearing the pending bit and setting the locked bit into a new clear_pending_set_locked() function. This patch also simplifies the trylock operation before queuing by calling queued_spin_trylock() directly. Signed-off-by: Waiman Long <Waiman.Long@hp.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Daniel J Blueman <daniel@numascale.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Douglas Hatch <doug.hatch@hp.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <paolo.bonzini@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1429901803-29771-5-git-send-email-Waiman.Long@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08locking/qspinlock: Add pending bitPeter Zijlstra (Intel)2-24/+107
Because the qspinlock needs to touch a second cacheline (the per-cpu mcs_nodes[]); add a pending bit and allow a single in-word spinner before we punt to the second cacheline. It is possible so observe the pending bit without the locked bit when the last owner has just released but the pending owner has not yet taken ownership. In this case we would normally queue -- because the pending bit is already taken. However, in this case the pending bit is guaranteed to be released 'soon', therefore wait for it and avoid queueing. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Waiman Long <Waiman.Long@hp.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Daniel J Blueman <daniel@numascale.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Douglas Hatch <doug.hatch@hp.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <paolo.bonzini@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1429901803-29771-4-git-send-email-Waiman.Long@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08locking/qspinlock, x86: Enable x86-64 to use queued spinlocksWaiman Long4-0/+30
This patch makes the necessary changes at the x86 architecture specific layer to enable the use of queued spinlocks for x86-64. As x86-32 machines are typically not multi-socket. The benefit of queue spinlock may not be apparent. So queued spinlocks are not enabled. Currently, there is some incompatibilities between the para-virtualized spinlock code (which hard-codes the use of ticket spinlock) and the queued spinlocks. Therefore, the use of queued spinlocks is disabled when the para-virtualized spinlock is enabled. The arch/x86/include/asm/qspinlock.h header file includes some x86 specific optimization which will make the queueds spinlock code perform better than the generic implementation. Signed-off-by: Waiman Long <Waiman.Long@hp.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Daniel J Blueman <daniel@numascale.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Douglas Hatch <doug.hatch@hp.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <paolo.bonzini@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1429901803-29771-3-git-send-email-Waiman.Long@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08locking/qspinlock: Introduce a simple generic 4-byte queued spinlockWaiman Long6-0/+408
This patch introduces a new generic queued spinlock implementation that can serve as an alternative to the default ticket spinlock. Compared with the ticket spinlock, this queued spinlock should be almost as fair as the ticket spinlock. It has about the same speed in single-thread and it can be much faster in high contention situations especially when the spinlock is embedded within the data structure to be protected. Only in light to moderate contention where the average queue depth is around 1-3 will this queued spinlock be potentially a bit slower due to the higher slowpath overhead. This queued spinlock is especially suit to NUMA machines with a large number of cores as the chance of spinlock contention is much higher in those machines. The cost of contention is also higher because of slower inter-node memory traffic. Due to the fact that spinlocks are acquired with preemption disabled, the process will not be migrated to another CPU while it is trying to get a spinlock. Ignoring interrupt handling, a CPU can only be contending in one spinlock at any one time. Counting soft IRQ, hard IRQ and NMI, a CPU can only have a maximum of 4 concurrent lock waiting activities. By allocating a set of per-cpu queue nodes and used them to form a waiting queue, we can encode the queue node address into a much smaller 24-bit size (including CPU number and queue node index) leaving one byte for the lock. Please note that the queue node is only needed when waiting for the lock. Once the lock is acquired, the queue node can be released to be used later. Signed-off-by: Waiman Long <Waiman.Long@hp.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Boris Ostrovsky <boris.ostrovsky@oracle.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Daniel J Blueman <daniel@numascale.com> Cc: David Vrabel <david.vrabel@citrix.com> Cc: Douglas Hatch <doug.hatch@hp.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Paolo Bonzini <paolo.bonzini@gmail.com> Cc: Paul E. McKenney <paulmck@linux.vnet.ibm.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Raghavendra K T <raghavendra.kt@linux.vnet.ibm.com> Cc: Rik van Riel <riel@redhat.com> Cc: Scott J Norton <scott.norton@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: virtualization@lists.linux-foundation.org Cc: xen-devel@lists.xenproject.org Link: http://lkml.kernel.org/r/1429901803-29771-2-git-send-email-Waiman.Long@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08kernel: Replace reference to ASSIGN_ONCE() with WRITE_ONCE() in commentPreeti U Murthy1-1/+1
Looks like commit : 43239cbe79fc ("kernel: Change ASSIGN_ONCE(val, x) to WRITE_ONCE(x, val)") left behind a reference to ASSIGN_ONCE(). Update this to WRITE_ONCE(). Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Borislav Petkov <bp@alien8.de> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: borntraeger@de.ibm.com Cc: dave@stgolabs.net Cc: paulmck@linux.vnet.ibm.com Link: http://lkml.kernel.org/r/20150430115721.22278.94082.stgit@preeti.in.ibm.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-08locking/rwsem: Reduce spinlock contention in wakeup after up_read()/up_write()Waiman Long2-0/+49
In up_write()/up_read(), rwsem_wake() will be called whenever it detects that some writers/readers are waiting. The rwsem_wake() function will take the wait_lock and call __rwsem_do_wake() to do the real wakeup. For a heavily contended rwsem, doing a spin_lock() on wait_lock will cause further contention on the heavily contended rwsem cacheline resulting in delay in the completion of the up_read/up_write operations. This patch makes the wait_lock taking and the call to __rwsem_do_wake() optional if at least one spinning writer is present. The spinning writer will be able to take the rwsem and call rwsem_wake() later when it calls up_write(). With the presence of a spinning writer, rwsem_wake() will now try to acquire the lock using trylock. If that fails, it will just quit. Suggested-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Waiman Long <Waiman.Long@hp.com> Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Davidlohr Bueso <dave@stgolabs.net> Acked-by: Jason Low <jason.low2@hp.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Borislav Petkov <bp@alien8.de> Cc: Douglas Hatch <doug.hatch@hp.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Scott J Norton <scott.norton@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1430428337-16802-2-git-send-email-Waiman.Long@hp.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-07Merge tag 'pm+acpi-4.1-rc3' of ↵Linus Torvalds6-7/+51
git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm Pull power management and ACPI fixes from Rafael Wysocki: "These include three regression fixes (PCI resources management, ACPI/PNP device enumeration, ACPI SBS on MacBook) and two ACPI documentation fixes related to GPIO. Specifics: - Fix for a PCI resources management regression introduced during the 4.0 cycle and related to the handling of ACPI resources' Producer/Consumer flags that turn out to be useless (Jiang Liu) - Fix for a MacBook regression related to the Smart Battery Subsystem (SBS) driver causing various problems (stalls on boot, failure to detect or report battery) to happen and introduced during the 3.18 cycle (Chris Bainbridge) - Fix for an ACPI/PNP device enumeration regression introduced during the 3.16 cycle caused by failing to include two PNP device IDs into the list of IDs that PNP device objects need to be created for (Witold Szczeponik) - Fixes for two minor mistakes in the ACPI GPIO properties documentation (Antonio Ospite, Rafael J Wysocki)" * tag 'pm+acpi-4.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm: ACPI / PNP: add two IDs to list for PNPACPI device enumeration ACPI / documentation: Fix ambiguity in the GPIO properties document ACPI / documentation: fix a sentence about GPIO resources ACPI / SBS: Add 5 us delay to fix SBS hangs on MacBook x86/PCI/ACPI: Make all resources except [io 0xcf8-0xcff] available on PCI bus
2015-05-07Merge branches 'acpi-resources', 'acpi-battery', 'acpi-doc' and 'acpi-pnp'Rafael J. Wysocki230-1649/+2700
* acpi-resources: x86/PCI/ACPI: Make all resources except [io 0xcf8-0xcff] available on PCI bus * acpi-battery: ACPI / SBS: Add 5 us delay to fix SBS hangs on MacBook * acpi-doc: ACPI / documentation: Fix ambiguity in the GPIO properties document ACPI / documentation: fix a sentence about GPIO resources * acpi-pnp: ACPI / PNP: add two IDs to list for PNPACPI device enumeration
2015-05-07Merge tag 'for-f2fs-4.1-rc3' of ↵Linus Torvalds4-5/+12
git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs Pull f2fs fixes from Jaegeuk Kim: "Fix a performance regression and a bug" * tag 'for-f2fs-4.1-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: f2fs: fix wrong error hanlder in f2fs_follow_link Revert "f2fs: enhance multi-threads performance"
2015-05-07Merge tag 'pinctrl-v4.1-3' of ↵Linus Torvalds7-13/+16
git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl Pull pin control fixes from Linus Walleij: "Here is a smallish set of pin control fixes for the v4.1 cycle, collected the last two weeks: - fix a real nasty legacy bug that has screwed up the protection of adding pinctrl maps dynamically. Normally this didn't happen so much but Dough Anderson ran into it and fixed it, kudos! - minor driver fixes for Qualcomm spmi, mediatek and Marvell drivers" * tag 'pinctrl-v4.1-3' of git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrl: pinctrl: Don't just pretend to protect pinctrl_maps, do it for real pinctrl: mediatek: mtk-common: initialize unmask pinctrl: qcom-spmi-mpp: Fix input value report pinctrl: qcom-spmi: Fix pin direction configuration pinctrl: mvebu: Fix mapping of pin 63 (gpo -> gpio)
2015-05-07Merge tag 'vfio-v4.1-rc3' of git://github.com/awilliam/linux-vfioLinus Torvalds2-4/+25
Pull vfio fixes from Alex Williamson: "Fix some undesirable behavior with the vfio device request interface: - increase verbosity of device request channel (Alex Williamson) - fix runaway interruptible timeout (Alex Williamson)" * tag 'vfio-v4.1-rc3' of git://github.com/awilliam/linux-vfio: vfio: Fix runaway interruptible timeout vfio-pci: Log device requests more verbosely
2015-05-07Merge tag 'for-linus' of git://github.com/dledford/linuxLinus Torvalds31-219/+568
Pull infiniband updates from Doug Ledford: "Minor updates for 4.1-rc Most of the changes are fairly small and well confined. The iWARP address reporting changes are the only ones that are a medium size. I had these queued up prior to rc1, but due to the shuffle in maintainers, they did not get submitted when I expected. My apologies for that. I feel comfortable with them however due to the testing they've received, so I left them in this submission" * tag 'for-linus' of git://github.com/dledford/linux: MAINTAINERS: Update InfiniBand subsystem maintainer MAINTAINERS: add include/rdma/ to InfiniBand subsystem IPoIB/CM: Fix indentation level iw_cxgb4: Remove negative advice dmesg warnings IB/core: Fix unaligned accesses IB/core: change rdma_gid2ip into void function as it always return zero IB/qib: use arch_phys_wc_add() IB/qib: add acounting for MTRR IB/core: dma unmap optimizations IB/core: dma map/unmap locking optimizations RDMA/cxgb4: Report the actual address of the remote connecting peer RDMA/nes: Report the actual address of the remote connecting peer RDMA/core: Enable the iWarp Port Mapper to provide the actual address of the connecting peer to its clients iw_cxgb4: enforce qp/cq id requirements iw_cxgb4: use BAR2 GTS register for T5 kernel mode CQs iw_cxgb4: 32b platform fixes iw_cxgb4: Cleanup register defines/MACROS RDMA/CMA: Canonize IPv4 on IPV6 sockets properly
2015-05-06Merge tag 'for-linus-4.1b-rc2-tag' of ↵Linus Torvalds21-74/+168
git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip Pull xen bug fixes from David Vrabel: - fix blkback regression if using persistent grants - fix various event channel related suspend/resume bugs - fix AMD x86 regression with X86_BUG_SYSRET_SS_ATTRS - SWIOTLB on ARM now uses frames <4 GiB (if available) so device only capable of 32-bit DMA work. * tag 'for-linus-4.1b-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip: xen: Add __GFP_DMA flag when xen_swiotlb_init gets free pages on ARM hypervisor/x86/xen: Unset X86_BUG_SYSRET_SS_ATTRS on Xen PV guests xen/events: Set irq_info->evtchn before binding the channel to CPU in __startup_pirq() xen/console: Update console event channel on resume xen/xenbus: Update xenbus event channel on resume xen/events: Clear cpu_evtchn_mask before resuming xen-pciback: Add name prefix to global 'permissive' variable xen: Suspend ticks on all CPUs during suspend xen/grant: introduce func gnttab_unmap_refs_sync() xen/blkback: safely unmap purge persistent grants
2015-05-06Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds6-17/+23
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "EFI fixes, and FPU fix, a ticket spinlock boundary condition fix and two build fixes" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/fpu: Always restore_xinit_state() when use_eager_cpu() x86: Make cpu_tss available to external modules efi: Fix error handling in add_sysfs_runtime_map_entry() x86/spinlocks: Fix regression in spinlock contention detection x86/mm: Clean up types in xlate_dev_mem_ptr() x86/efi: Store upper bits of command line buffer address in ext_cmd_line_ptr efivarfs: Ensure VariableName is NUL-terminated
2015-05-06Merge branch 'perf-urgent-for-linus' of ↵Linus Torvalds13-77/+114
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull perf fixes from Ingo Molnar: "Mostly tooling fixes, but also an uncore PMU driver fix and an uncore PMU driver hardware-enablement addition" * 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: perf probe: Fix segfault if passed with ''. perf report: Fix -T/--threads option to work again perf bench numa: Fix immediate meeting of convergence condition perf bench numa: Fixes of --quiet argument perf bench futex: Fix hung wakeup tasks after requeueing perf probe: Fix bug with global variables handling perf top: Fix a segfault when kernel map is restricted. tools lib traceevent: Fix build failure on 32-bit arch perf kmem: Fix compiles on RHEL6/OL6 tools lib api: Undefine _FORTIFY_SOURCE before setting it perf kmem: Consistently use PRIu64 for printing u64 values perf trace: Disable events and drain events when forked workload ends perf trace: Enable events when doing system wide tracing and starting a workload perf/x86/intel/uncore: Move PCI IDs for IMC to uncore driver perf/x86/intel/uncore: Add support for Intel Haswell ULT (lower power Mobile Processor) IMC uncore PMUs perf/x86/intel: Add cpu_(prepare|starting|dying) for core_pmu
2015-05-06Merge branch 'core-urgent-for-linus' of ↵Linus Torvalds2-7/+10
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull RCU fix from Ingo Molnar: "An RCU Kconfig fix that eliminates an annoying interactive kconfig question for CONFIG_RCU_TORTURE_TEST_SLOW_INIT" * 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: rcu: Control grace-period delays directly from value
2015-05-06pinctrl: Don't just pretend to protect pinctrl_maps, do it for realDoug Anderson3-8/+6
Way back, when the world was a simpler place and there was no war, no evil, and no kernel bugs, there was just a single pinctrl lock. That was how the world was when (57291ce pinctrl: core device tree mapping table parsing support) was written. In that case, there were instances where the pinctrl mutex was already held when pinctrl_register_map() was called, hence a "locked" parameter was passed to the function to indicate that the mutex was already locked (so we shouldn't lock it again). A few years ago in (42fed7b pinctrl: move subsystem mutex to pinctrl_dev struct), we switched to a separate pinctrl_maps_mutex. ...but (oops) we forgot to re-think about the whole "locked" parameter for pinctrl_register_map(). Basically the "locked" parameter appears to still refer to whether the bigger pinctrl_dev mutex is locked, but we're using it to skip locks of our (now separate) pinctrl_maps_mutex. That's kind of a bad thing(TM). Probably nobody noticed because most of the calls to pinctrl_register_map happen at boot time and we've got synchronous device probing. ...and even cases where we're asynchronous don't end up actually hitting the race too often. ...but after banging my head against the wall for a bug that reproduced 1 out of 1000 reboots and lots of looking through kgdb, I finally noticed this. Anyway, we can now safely remove the "locked" parameter and go back to a war-free, evil-free, and kernel-bug-free world. Fixes: 42fed7ba44e4 ("pinctrl: move subsystem mutex to pinctrl_dev struct") Signed-off-by: Doug Anderson <dianders@chromium.org> Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
2015-05-06xen: Add __GFP_DMA flag when xen_swiotlb_init gets free pages on ARMStefano Stabellini4-1/+22
Make sure that xen_swiotlb_init allocates buffers that are DMA capable when at least one memblock is available below 4G. Otherwise we assume that all devices on the SoC can cope with >4G addresses. We do this on ARM and ARM64, where dom0 is mapped 1:1, so pfn == mfn in this case. No functional changes on x86. From: Chen Baozi <baozich@gmail.com> Signed-off-by: Chen Baozi <baozich@gmail.com> Signed-off-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com> Tested-by: Chen Baozi <baozich@gmail.com> Acked-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by: David Vrabel <david.vrabel@citrix.com>
2015-05-06x86/fpu: Always restore_xinit_state() when use_eager_cpu()Bobby Powers1-5/+7
The following commit: f893959b0898 ("x86/fpu: Don't abuse drop_init_fpu() in flush_thread()") removed drop_init_fpu() usage from flush_thread(). This seems to break things for me - the Go 1.4 test suite fails all over the place with floating point comparision errors (offending commit found through bisection). The functional change was that flush_thread() after this commit only calls restore_init_xstate() when both use_eager_fpu() and !used_math() are true. drop_init_fpu() (now fpu_reset_state()) calls restore_init_xstate() regardless of whether current used_math() - apply the same logic here. Switch used_math() -> tsk_used_math(tsk) to consistently use the grabbed tsk instead of current, like in the rest of flush_thread(). Tested-by: Dave Hansen <dave.hansen@intel.com> Signed-off-by: Bobby Powers <bobbypowers@gmail.com> Signed-off-by: Borislav Petkov <bp@suse.de> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Borislav Petkov <bp@alien8.de> Cc: Fenghua Yu <fenghua.yu@intel.com> Cc: H. Peter Anvin <hpa@zytor.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Pekka Riikonen <priikone@iki.fi> Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com> Cc: Rik van Riel <riel@redhat.com> Cc: Suresh Siddha <sbsiddha@gmail.com> Cc: Thomas Gleixner <tglx@linutronix.de> Fixes: f893959b ("x86/fpu: Don't abuse drop_init_fpu() in flush_thread()") Link: http://lkml.kernel.org/r/1430147441-9820-1-git-send-email-bobbypowers@gmail.com Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-06Merge tag 'efi-urgent' of ↵Ingo Molnar3-4/+6
git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/urgent Pull EFI fixes from Matt Fleming: * Avoid garbage names in efivarfs due to buggy firmware by zeroing EFI variable name. (Ross Lagerwall) * Stop erroneously dropping upper 32 bits of boot command line pointer in EFI boot stub and stash them in ext_cmd_line_ptr. (Roy Franz) * Fix double-free bug in error handling code path of EFI runtime map code. (Dan Carpenter) Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-06Merge tag 'perf-urgent-for-mingo' of ↵Ingo Molnar2-1/+3
git://git.kernel.org/pub/scm/linux/kernel/git/acme/linux into perf/urgent Pull perf/urgent fixes from Arnaldo Carvalho de Melo: - Fix 'perf probe -a' segfault if passed with '' (Wang Nan) - Fix report -T/--threads option (Namhyung Kim) Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com> Signed-off-by: Ingo Molnar <mingo@kernel.org>
2015-05-05Merge tag 'for-linus-4.1-1' of git://git.code.sf.net/p/openipmi/linux-ipmiLinus Torvalds4-45/+193
Pull IPMI fixes from Corey Minyard: "Lots of minor IPMI fixes, especially ones that have have come up since the SSIF driver has been in the main kernel for a while" * tag 'for-linus-4.1-1' of git://git.code.sf.net/p/openipmi/linux-ipmi: ipmi: Fix multi-part message handling ipmi: Add alert handling to SSIF ipmi: Fix a problem that messages are not issued in run_to_completion mode ipmi: Report an error if ACPI _IFT doesn't exist ipmi: Remove unused including <linux/version.h> ipmi: Don't report err in the SI driver for SSIF devices ipmi: Remove incorrect use of seq_has_overflowed ipmi:ssif: Ignore spaces when comparing I2C adapter names ipmi_ssif: Fix the logic on user-supplied addresses
2015-05-05Merge branch 'akpm' (patches from Andrew)Linus Torvalds17-75/+429
Merge misc fixes from Andrew Morton: "16 patches This includes a new rtc driver for the Abracon AB x80x and isn't very appropriate for -rc2. It was still being fiddled with a bit during the merge window and I fell asleep during -rc1" [ So I took the new driver, it seems small and won't regress anything. I'm a softy. - Linus ] * emailed patches from Andrew Morton <akpm@linux-foundation.org>: rtc: armada38x: fix concurrency access in armada38x_rtc_set_time ocfs2: dlm: fix race between purge and get lock resource nilfs2: fix sanity check of btree level in nilfs_btree_root_broken() util_macros.h: have array pointer point to array of constants configfs: init configfs module earlier at boot time mm/hwpoison-inject: check PageLRU of hpage mm/hwpoison-inject: fix refcounting in no-injection case mm: soft-offline: fix num_poisoned_pages counting on concurrent events rtc: add rtc-abx80x, a driver for the Abracon AB x80x i2c rtc Documentation: bindings: add abracon,abx80x kasan: show gcc version requirements in Kconfig and Documentation mm/memory-failure: call shake_page() when error hits thp tail page lib: delete lib/find_last_bit.c MAINTAINERS: add co-maintainer for LED subsystem zram: add Designated Reviewer for zram in MAINTAINERS revert "zram: move compact_store() to sysfs functions area"
2015-05-05Merge tag 'platform-drivers-x86-v4.1-2' of ↵Linus Torvalds2-1/+8
git://git.infradead.org/users/dvhart/linux-platform-drivers-x86 Pull x86 platform driver fixes from Darren Hart: "This includes a trivial warning and adding a Lenovo laptop to an existing quirk. I've held off on things like the latter in the past, but I didn't feel it was risky enough to push out to 4.2. - thinkpad_acpi: Fix warning for static not at beginning - ideapad_laptop: Add Lenovo G40-30 to devices without radio switch" * tag 'platform-drivers-x86-v4.1-2' of git://git.infradead.org/users/dvhart/linux-platform-drivers-x86: thinkpad_acpi: Fix warning for static not at beginning ideapad_laptop: Add Lenovo G40-30 to devices without radio switch
2015-05-05ipmi: Fix multi-part message handlingCorey Minyard1-13/+38
Lots of little fixes for multi-part messages: The values was not being re-initialized, if something went wrong handling a multi-part message and it got left in a bad state, it might be an issue. The commands were not correct when issuing multi-part reads, the code was not passing in the proper value for commands. Also clean up some minor formatting issues. Get the block number from the right location, limit the maximum send message size to 63 bytes and explain why, and fix some minor sylistic issues. Signed-off-by: Corey Minyard <cminyard@mvista.com>
2015-05-05ipmi: Add alert handling to SSIFCorey Minyard1-16/+116
The SSIF interface can optionally have an SMBus alert come in when data is ready. Unfortunately, the IPMI spec gives wiggle room to the implementer to allow them to always have the alert enabled, even if the driver doesn't enable it. So implement alerts. If you don't in this situation, the SMBus alert handling will constantly complain. Signed-off-by: Corey Minyard <cminyard@mvista.com>
2015-05-05ipmi: Fix a problem that messages are not issued in run_to_completion modeHidehiro Kawai1-2/+1
start_next_msg() issues a message placed in smi_info->waiting_msg if it is non-NULL. However, sender() sets a message to smi_info->curr_msg and NULL to smi_info->waiting_msg in the context of run_to_completion mode. As the result, it leads an infinite loop by waiting the completion of unissued message when leaving dying message after kernel panic. sender() should set the message to smi_info->waiting_msg not curr_msg. Signed-off-by: Hidehiro Kawai <hidehiro.kawai.ez@hitachi.com> Signed-off-by: Corey Minyard <cminyard@mvista.com>
2015-05-05ipmi: Report an error if ACPI _IFT doesn't existCorey Minyard1-1/+3
When probing an ACPI table, report a specific error, instead of just returning an error, if _IFT doesn't exist. Signed-off-by: Corey Minyard <cminyard@mvista.com>
2015-05-05ipmi: Remove unused including <linux/version.h>Wei Yongjun1-1/+0
Remove including <linux/version.h> that don't need it. Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn> Signed-off-by: Corey Minyard <cminyard@mvista.com>
2015-05-05rtc: armada38x: fix concurrency access in armada38x_rtc_set_timeGregory CLEMENT1-12/+12
While setting the time, the RTC TIME register should not be accessed. However due to hardware constraints, setting the RTC time involves sleeping during 100ms. This sleep was done outside the critical section protected by the spinlock, so it was possible to read the RTC TIME register and get an incorrect value. This patch introduces a mutex for protecting the RTC TIME access, unlike the spinlock it is allowed to sleep in a critical section protected by a mutex. The RTC STATUS register can still be used from the interrupt handler but it has no effect on setting the time. Signed-off-by: Gregory CLEMENT <gregory.clement@free-electrons.com> Acked-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Acked-by: Andrew Lunn <andrew@lunn.ch> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: <stable@vger.kernel.org> [4.0] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05ocfs2: dlm: fix race between purge and get lock resourceJunxiao Bi1-0/+13
There is a race window in dlm_get_lock_resource(), which may return a lock resource which has been purged. This will cause the process to hang forever in dlmlock() as the ast msg can't be handled due to its lock resource not existing. dlm_get_lock_resource { ... spin_lock(&dlm->spinlock); tmpres = __dlm_lookup_lockres_full(dlm, lockid, namelen, hash); if (tmpres) { spin_unlock(&dlm->spinlock); >>>>>>>> race window, dlm_run_purge_list() may run and purge the lock resource spin_lock(&tmpres->spinlock); ... spin_unlock(&tmpres->spinlock); } } Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05nilfs2: fix sanity check of btree level in nilfs_btree_root_broken()Ryusuke Konishi2-2/+2
The range check for b-tree level parameter in nilfs_btree_root_broken() is wrong; it accepts the case of "level == NILFS_BTREE_LEVEL_MAX" even though the level is limited to values in the range of 0 to (NILFS_BTREE_LEVEL_MAX - 1). Since the level parameter is read from storage device and used to index nilfs_btree_path array whose element count is NILFS_BTREE_LEVEL_MAX, it can cause memory overrun during btree operations if the boundary value is set to the level parameter on device. This fixes the broken sanity check and adds a comment to clarify that the upper bound NILFS_BTREE_LEVEL_MAX is exclusive. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05util_macros.h: have array pointer point to array of constantsGuenter Roeck1-1/+1
Using the new find_closest() macro can result in the following sparse warnings. drivers/hwmon/lm85.c:194:16: warning: incorrect type in initializer (different modifiers) drivers/hwmon/lm85.c:194:16: expected int *__fc_a drivers/hwmon/lm85.c:194:16: got int static const [toplevel] *<noident> drivers/hwmon/lm85.c:210:16: warning: incorrect type in initializer (different modifiers) drivers/hwmon/lm85.c:210:16: expected int *__fc_a drivers/hwmon/lm85.c:210:16: got int const *map This is because the array passed to find_closest() will typically be declared as array of constants, but the macro declares a non-constant pointer to it. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Cc: Bartosz Golaszewski <bgolaszewski@baylibre.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05configfs: init configfs module earlier at boot timeDaniel Baluta1-1/+1
We need this earlier in the boot process to allow various subsystems to use configfs (e.g Industrial IIO). Also, debugfs is at core_initcall level and configfs should be on the same level from infrastructure point of view. Signed-off-by: Daniel Baluta <daniel.baluta@intel.com> Suggested-by: Lars-Peter Clausen <lars@metafoo.de> Reviewed-by: Christoph Hellwig <hch@lst.de> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05mm/hwpoison-inject: check PageLRU of hpageNaoya Horiguchi1-3/+3
Hwpoison injector checks PageLRU of the raw target page to find out whether the page is an appropriate target, but current code now filters out thp tail pages, which prevents us from testing for such cases via this interface. So let's check hpage instead of p. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Dean Nelson <dnelson@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05mm/hwpoison-inject: fix refcounting in no-injection caseNaoya Horiguchi1-2/+5
Hwpoison injection via debugfs:hwpoison/corrupt-pfn takes a refcount of the target page. But current code doesn't release it if the target page is not supposed to be injected, which results in memory leak. This patch simply adds the refcount releasing code. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Dean Nelson <dnelson@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05mm: soft-offline: fix num_poisoned_pages counting on concurrent eventsNaoya Horiguchi1-4/+4
If multiple soft offline events hit one free page/hugepage concurrently, soft_offline_page() can handle the free page/hugepage multiple times, which makes num_poisoned_pages counter increased more than once. This patch fixes this wrong counting by checking TestSetPageHWPoison for normal papes and by checking the return value of dequeue_hwpoisoned_huge_page() for hugepages. Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Acked-by: Dean Nelson <dnelson@redhat.com> Cc: Andi Kleen <andi@firstfloor.org> Cc: <stable@vger.kernel.org> [3.14+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05rtc: add rtc-abx80x, a driver for the Abracon AB x80x i2c rtcPhilippe De Muyter3-0/+318
This is a basic driver for the ultra-low-power Abracon AB x80x series of RTC chips. It supports in particular, the supersets AB0805 and AB1805. It allows reading and writing the time, and enables the supercapacitor/ battery charger. [arnd@arndb.de: abx805 depends on i2c] [alexandre.belloni@free-electrons.com: renam buffer from date to buf in abx80x_rtc_read_time()] Signed-off-by: Philippe De Muyter <phdm@macqel.be> Cc: Alessandro Zummo <a.zummo@towertech.it> Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Cc: Paul Bolle <pebolle@tiscali.nl> Cc: Arnd Bergmann <arnd@arndb.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05Documentation: bindings: add abracon,abx80xAlexandre Belloni1-0/+30
Document the bindings for abracon,abx80x and related compatibles. Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com> Cc: Philippe De Muyter <phdm@macqel.be> Cc: Alessandro Zummo <a.zummo@towertech.it> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Paul Bolle <pebolle@tiscali.nl> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05kasan: show gcc version requirements in Kconfig and DocumentationJoe Perches2-5/+11
The documentation shows a need for gcc > 4.9.2, but it's really >=. The Kconfig entries don't show require versions so add them. Correct a latter/later typo too. Also mention that gcc 5 required to catch out of bounds accesses to global and stack variables. Signed-off-by: Joe Perches <joe@perches.com> Signed-off-by: Andrey Ryabinin <a.ryabinin@samsung.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05mm/memory-failure: call shake_page() when error hits thp tail pageNaoya Horiguchi1-4/+4
Currently memory_failure() calls shake_page() to sweep pages out from pcplists only when the victim page is 4kB LRU page or thp head page. But we should do this for a thp tail page too. Consider that a memory error hits a thp tail page whose head page is on a pcplist when memory_failure() runs. Then, the current kernel skips shake_pages() part, so hwpoison_user_mappings() returns without calling split_huge_page() nor try_to_unmap() because PageLRU of the thp head is still cleared due to the skip of shake_page(). As a result, me_huge_page() runs for the thp, which is broken behavior. One effect is a leak of the thp. And another is to fail to isolate the memory error, so later access to the error address causes another MCE, which kills the processes which used the thp. This patch fixes this problem by calling shake_page() for thp tail case. Fixes: 385de35722c9 ("thp: allow a hwpoisoned head page to be put back to LRU") Signed-off-by: Naoya Horiguchi <n-horiguchi@ah.jp.nec.com> Reviewed-by: Andi Kleen <ak@linux.intel.com> Acked-by: Dean Nelson <dnelson@redhat.com> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Hidetoshi Seto <seto.hidetoshi@jp.fujitsu.com> Cc: Jin Dongming <jin.dongming@np.css.fujitsu.com> Cc: <stable@vger.kernel.org> [3.4+] Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05lib: delete lib/find_last_bit.cYury Norov1-41/+0
The file lib/find_last_bit.c was no longer used and supposed to be deleted by commit 8f6f19dd51 ("lib: move find_last_bit to lib/find_next_bit.c") but that delete didn't happen. This gets rid of it. Signed-off-by: Yury Norov <yury.norov@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05MAINTAINERS: add co-maintainer for LED subsystemAndrew Morton1-0/+1
Add myself (Jacek Anaszewski) as a co-maintainer for the LED subsystem. Signed-off-by: Jacek Anaszewski <j.anaszewski@samsung.com> Acked-by: Bryan Wu <cooloney@gmail.com> Cc: Richard Purdie <rpurdie@rpsys.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-05-05zram: add Designated Reviewer for zram in MAINTAINERSMinchan Kim1-0/+1
Sergey Senozhatsky has contributed/reviewed to zram for a long time. He is really helpful for maintaining zram so I want for him to continue helping me as Designated Reviewer unless he hates it. Signed-off-by: Minchan Kim <minchan@kernel.org> Cc: Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>