- 13 May, 2015 2 commits
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Thomas Gleixner authored
We removed the only user of this define in the rtmutex code. Get rid of it. Signed-off-by:Thomas Gleixner <tglx@linutronix.de> Cc: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
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Sebastian Andrzej Siewior authored
The rtmutex code is the only user of __HAVE_ARCH_CMPXCHG and we have a few other user of cmpxchg() which do not care about __HAVE_ARCH_CMPXCHG. This define was first introduced in 23f78d4a ("[PATCH] pi-futex: rt mutex core") which is v2.6.18. The generic cmpxchg was introduced later in 068fbad2 ("Add cmpxchg_local to asm-generic for per cpu atomic operations") which is v2.6.25. Back then something was required to get rtmutex working with the fast path on architectures without cmpxchg and this seems to be the result. It popped up recently on rt-users because ARM (v6+) does not define __HAVE_ARCH_CMPXCHG (even that it implements it) which results in slower locking performance in the fast path. To put some numbers on it: preempt -RT, am335x, 10 loops of 100000 invocations of rt_spin_lock() + rt_spin_unlock() (time "total" is the average of the 10 loops for the 100000 invocations, "loop" is "total / 100000 * 1000"): cmpxchg | slowpath used || cmpxchg used | total | loop || total | loop --------|-----------|-------||------------|------- ARMv6 | 9129.4 us | 91 ns || 3311.9 us | 33 ns generic | 9360.2 us | 94 ns || 10834.6 us | 108 ns ----------------------------||-------------------- Forcing it to generic cmpxchg() made things worse for the slowpath and even worse in cmpxchg() path. It boils down to 14ns more per lock+unlock in a cache hot loop so it might not be that much in real world. The last test was a substitute for pre ARMv6 machine but then I was able to perform the comparison on imx28 which is ARMv5 and therefore is always is using the generic cmpxchg implementation. And the numbers: | total | loop -------- |----------- |-------- slowpath | 263937.2 us | 2639 ns cmpxchg | 16934.2 us | 169 ns -------------------------------- The numbers are larger since the machine is slower in general. However, letting rtmutex use cmpxchg() instead the slowpath seem to improve things. Since from the ARM (tested on am335x + imx28) point of view always using cmpxchg() in rt_mutex_lock() + rt_mutex_unlock() makes sense I would drop the define. Signed-off-by:
Sebastian Andrzej Siewior <bigeasy@linutronix.de> Cc: Arnd Bergmann <arnd@arndb.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: will.deacon@arm.com Cc: linux-arm-kernel@lists.infradead.org Link: http://lkml.kernel.org/r/20150225175613.GE6823@linutronix.deSigned-off-by:
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- 12 May, 2015 1 commit
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Waiman Long authored
To be consistent with the queued spinlocks which use CONFIG_QUEUED_SPINLOCKS config parameter, the one for the queued rwlocks is now renamed to CONFIG_QUEUED_RWLOCKS. Signed-off-by:
Waiman Long <Waiman.Long@hp.com> 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: Peter Zijlstra <peterz@infradead.org> Cc: Scott J Norton <scott.norton@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Link: http://lkml.kernel.org/r/1431367031-36697-1-git-send-email-Waiman.Long@hp.comSigned-off-by:
Ingo Molnar <mingo@kernel.org>
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- 11 May, 2015 2 commits
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Ingo Molnar authored
Valentin Rothberg reported that we use CONFIG_QUEUED_SPINLOCKS in arch/x86/kernel/paravirt_patch_32.c, while the symbol is called CONFIG_QUEUED_SPINLOCK. (Note the extra 'S') But the typo was natural: the proper English term for such a generic object would be 'queued spinlocks' - so rename this and related symbols accordingly to the plural form. Reported-by:
Valentin Rothberg <valentinrothberg@gmail.com> Cc: Douglas Hatch <doug.hatch@hp.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Scott J Norton <scott.norton@hp.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Waiman Long <Waiman.Long@hp.com> Cc: linux-kernel@vger.kernel.org Signed-off-by:
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Waiman Long authored
The xchg() function was used in pv_wait_node() to set a certain value and provide a memory barrier which is what the set_mb() function is for. This patch replaces the xchg() call by set_mb(). Suggested-by:
Linus Torvalds <torvalds@linux-foundation.org> Signed-off-by:
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- 08 May, 2015 13 commits
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David Vrabel authored
This patch adds the necessary Xen specific code to allow Xen to support the CPU halting and kicking operations needed by the queue spinlock PV code. Signed-off-by:
David Vrabel <david.vrabel@citrix.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: 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/1429901803-29771-12-git-send-email-Waiman.Long@hp.comSigned-off-by:
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Waiman Long authored
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:
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Peter Zijlstra (Intel) authored
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:
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Waiman Long authored
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:
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Peter Zijlstra (Intel) authored
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:
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Waiman Long authored
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: -
Peter Zijlstra (Intel) authored
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:
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Waiman Long authored
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: -
Peter Zijlstra (Intel) authored
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:
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Waiman Long authored
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:
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Waiman Long authored
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:
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Preeti U Murthy authored
Looks like commit : 43239cbe ("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:
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Waiman Long authored
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:
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.comSigned-off-by:
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- 07 May, 2015 6 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pmLinus Torvalds authored
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 -
Rafael J. Wysocki authored
* 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
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git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fsLinus Torvalds authored
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"
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git://git.kernel.org/pub/scm/linux/kernel/git/linusw/linux-pinctrlLinus Torvalds authored
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) -
git://github.com/awilliam/linux-vfioLinus Torvalds authored
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
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git://github.com/dledford/linuxLinus Torvalds authored
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
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- 06 May, 2015 16 commits
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git://git.kernel.org/pub/scm/linux/kernel/git/xen/tipLinus Torvalds authored
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
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
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
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
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
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tipLinus Torvalds authored
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
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Doug Anderson authored
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 (57291ce2 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 (42fed7ba 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: 42fed7ba ("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>
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Stefano Stabellini authored
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:
Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> Signed-off-by:
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Bobby Powers authored
The following commit: f893959b ("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.comSigned-off-by:
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Ingo Molnar authored
Merge tag 'efi-urgent' of 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:
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Ingo Molnar authored
Merge tag 'perf-urgent-for-mingo' of 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:
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git://git.code.sf.net/p/openipmi/linux-ipmiLinus Torvalds authored
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
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Linus Torvalds authored
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"
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Linus Torvalds authored
Merge tag 'platform-drivers-x86-v4.1-2' of 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
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Corey Minyard authored
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>
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Corey Minyard authored
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: -
Hidehiro Kawai authored
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:
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Corey Minyard authored
When probing an ACPI table, report a specific error, instead of just returning an error, if _IFT doesn't exist. Signed-off-by:
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