Merge branch 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull core locking updates from Ingo Molnar:
 "The biggest change is the MCS spinlock generalization changes from Tim
  Chen, Peter Zijlstra, Jason Low et al.  There's also lockdep
  fixes/enhancements from Oleg Nesterov, in particular a false negative
  fix related to lockdep_set_novalidate_class() usage"

* 'core-locking-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (22 commits)
  locking/mutex: Fix debug checks
  locking/mutexes: Add extra reschedule point
  locking/mutexes: Introduce cancelable MCS lock for adaptive spinning
  locking/mutexes: Unlock the mutex without the wait_lock
  locking/mutexes: Modify the way optimistic spinners are queued
  locking/mutexes: Return false if task need_resched() in mutex_can_spin_on_owner()
  locking: Move mcs_spinlock.h into kernel/locking/
  m68k: Skip futex_atomic_cmpxchg_inatomic() test
  futex: Allow architectures to skip futex_atomic_cmpxchg_inatomic() test
  Revert "sched/wait: Suppress Sparse 'variable shadowing' warning"
  lockdep: Change lockdep_set_novalidate_class() to use _and_name
  lockdep: Change mark_held_locks() to check hlock->check instead of lockdep_no_validate
  lockdep: Don't create the wrong dependency on hlock->check == 0
  lockdep: Make held_lock->check and "int check" argument bool
  locking/mcs: Allow architecture specific asm files to be used for contended case
  locking/mcs: Order the header files in Kbuild of each architecture in alphabetical order
  sched/wait: Suppress Sparse 'variable shadowing' warning
  hung_task/Documentation: Fix hung_task_warnings description
  locking/mcs: Allow architectures to hook in to contended paths
  locking/mcs: Micro-optimize the MCS code, add extra comments
  ...
This commit is contained in:
Linus Torvalds 2014-03-31 10:59:39 -07:00
commit 462bf234a8
46 changed files with 587 additions and 215 deletions

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@ -320,10 +320,11 @@ This file shows up if CONFIG_DETECT_HUNG_TASK is enabled.
==============================================================
hung_task_warning:
hung_task_warnings:
The maximum number of warnings to report. During a check interval
When this value is reached, no more the warnings will be reported.
if a hung task is detected, this value is decreased by 1.
When this value reaches 0, no more warnings will be reported.
This file shows up if CONFIG_DETECT_HUNG_TASK is enabled.
-1: report an infinite number of warnings.

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@ -1,7 +1,8 @@
generic-y += clkdev.h
generic-y += exec.h
generic-y += trace_clock.h
generic-y += preempt.h
generic-y += hash.h
generic-y += mcs_spinlock.h
generic-y += preempt.h
generic-y += trace_clock.h

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@ -1,15 +1,15 @@
generic-y += auxvec.h
generic-y += barrier.h
generic-y += bugs.h
generic-y += bitsperlong.h
generic-y += bugs.h
generic-y += clkdev.h
generic-y += cputime.h
generic-y += device.h
generic-y += div64.h
generic-y += emergency-restart.h
generic-y += errno.h
generic-y += fcntl.h
generic-y += fb.h
generic-y += fcntl.h
generic-y += ftrace.h
generic-y += hardirq.h
generic-y += hash.h
@ -22,6 +22,7 @@ generic-y += kmap_types.h
generic-y += kvm_para.h
generic-y += local.h
generic-y += local64.h
generic-y += mcs_spinlock.h
generic-y += mman.h
generic-y += msgbuf.h
generic-y += param.h
@ -30,6 +31,7 @@ generic-y += pci.h
generic-y += percpu.h
generic-y += poll.h
generic-y += posix_types.h
generic-y += preempt.h
generic-y += resource.h
generic-y += scatterlist.h
generic-y += sembuf.h
@ -48,4 +50,3 @@ generic-y += ucontext.h
generic-y += user.h
generic-y += vga.h
generic-y += xor.h
generic-y += preempt.h

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@ -7,16 +7,19 @@ generic-y += current.h
generic-y += emergency-restart.h
generic-y += errno.h
generic-y += exec.h
generic-y += hash.h
generic-y += ioctl.h
generic-y += ipcbuf.h
generic-y += irq_regs.h
generic-y += kdebug.h
generic-y += local.h
generic-y += local64.h
generic-y += mcs_spinlock.h
generic-y += msgbuf.h
generic-y += param.h
generic-y += parport.h
generic-y += poll.h
generic-y += preempt.h
generic-y += resource.h
generic-y += sections.h
generic-y += segment.h
@ -33,5 +36,3 @@ generic-y += termios.h
generic-y += timex.h
generic-y += trace_clock.h
generic-y += unaligned.h
generic-y += preempt.h
generic-y += hash.h

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@ -12,6 +12,7 @@ generic-y += dma.h
generic-y += emergency-restart.h
generic-y += errno.h
generic-y += ftrace.h
generic-y += hash.h
generic-y += hw_irq.h
generic-y += ioctl.h
generic-y += ioctls.h
@ -22,12 +23,14 @@ generic-y += kmap_types.h
generic-y += kvm_para.h
generic-y += local.h
generic-y += local64.h
generic-y += mcs_spinlock.h
generic-y += mman.h
generic-y += msgbuf.h
generic-y += mutex.h
generic-y += pci.h
generic-y += poll.h
generic-y += posix_types.h
generic-y += preempt.h
generic-y += resource.h
generic-y += scatterlist.h
generic-y += sections.h
@ -38,8 +41,8 @@ generic-y += shmbuf.h
generic-y += sizes.h
generic-y += socket.h
generic-y += sockios.h
generic-y += switch_to.h
generic-y += swab.h
generic-y += switch_to.h
generic-y += termbits.h
generic-y += termios.h
generic-y += topology.h
@ -49,5 +52,3 @@ generic-y += unaligned.h
generic-y += user.h
generic-y += vga.h
generic-y += xor.h
generic-y += preempt.h
generic-y += hash.h

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@ -1,22 +1,23 @@
generic-y += clkdev.h
generic-y += cputime.h
generic-y += delay.h
generic-y += device.h
generic-y += div64.h
generic-y += emergency-restart.h
generic-y += exec.h
generic-y += futex.h
generic-y += preempt.h
generic-y += irq_regs.h
generic-y += param.h
generic-y += local.h
generic-y += local64.h
generic-y += percpu.h
generic-y += scatterlist.h
generic-y += sections.h
generic-y += topology.h
generic-y += trace_clock.h
generic-y += clkdev.h
generic-y += cputime.h
generic-y += delay.h
generic-y += device.h
generic-y += div64.h
generic-y += emergency-restart.h
generic-y += exec.h
generic-y += futex.h
generic-y += hash.h
generic-y += irq_regs.h
generic-y += local.h
generic-y += local64.h
generic-y += mcs_spinlock.h
generic-y += param.h
generic-y += percpu.h
generic-y += preempt.h
generic-y += scatterlist.h
generic-y += sections.h
generic-y += topology.h
generic-y += trace_clock.h
generic-y += vga.h
generic-y += xor.h
generic-y += hash.h
generic-y += xor.h

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@ -10,6 +10,7 @@ generic-y += emergency-restart.h
generic-y += errno.h
generic-y += fb.h
generic-y += futex.h
generic-y += hash.h
generic-y += hw_irq.h
generic-y += ioctl.h
generic-y += ipcbuf.h
@ -17,14 +18,16 @@ generic-y += irq_regs.h
generic-y += kdebug.h
generic-y += kmap_types.h
generic-y += kvm_para.h
generic-y += local64.h
generic-y += local.h
generic-y += local64.h
generic-y += mcs_spinlock.h
generic-y += mman.h
generic-y += msgbuf.h
generic-y += mutex.h
generic-y += param.h
generic-y += percpu.h
generic-y += pgalloc.h
generic-y += preempt.h
generic-y += resource.h
generic-y += scatterlist.h
generic-y += sembuf.h
@ -44,5 +47,3 @@ generic-y += ucontext.h
generic-y += unaligned.h
generic-y += user.h
generic-y += xor.h
generic-y += preempt.h
generic-y += hash.h

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@ -15,6 +15,7 @@ generic-y += exec.h
generic-y += fb.h
generic-y += fcntl.h
generic-y += futex.h
generic-y += hash.h
generic-y += hw_irq.h
generic-y += io.h
generic-y += ioctl.h
@ -24,6 +25,7 @@ generic-y += irq_regs.h
generic-y += kdebug.h
generic-y += kmap_types.h
generic-y += local.h
generic-y += mcs_spinlock.h
generic-y += mman.h
generic-y += mmu.h
generic-y += mmu_context.h
@ -34,6 +36,7 @@ generic-y += percpu.h
generic-y += pgalloc.h
generic-y += poll.h
generic-y += posix_types.h
generic-y += preempt.h
generic-y += resource.h
generic-y += scatterlist.h
generic-y += segment.h
@ -56,5 +59,3 @@ generic-y += ucontext.h
generic-y += user.h
generic-y += vga.h
generic-y += xor.h
generic-y += preempt.h
generic-y += hash.h

View File

@ -9,8 +9,9 @@ generic-y += exec.h
generic-y += hash.h
generic-y += kvm_para.h
generic-y += linkage.h
generic-y += mcs_spinlock.h
generic-y += module.h
generic-y += preempt.h
generic-y += trace_clock.h
generic-y += vga.h
generic-y += xor.h
generic-y += preempt.h

View File

@ -1,6 +1,7 @@
generic-y += clkdev.h
generic-y += exec.h
generic-y += trace_clock.h
generic-y += preempt.h
generic-y += hash.h
generic-y += mcs_spinlock.h
generic-y += preempt.h
generic-y += trace_clock.h

View File

@ -25,14 +25,16 @@ generic-y += ipcbuf.h
generic-y += irq_regs.h
generic-y += kdebug.h
generic-y += kmap_types.h
generic-y += local64.h
generic-y += local.h
generic-y += local64.h
generic-y += mcs_spinlock.h
generic-y += mman.h
generic-y += msgbuf.h
generic-y += pci.h
generic-y += percpu.h
generic-y += poll.h
generic-y += posix_types.h
generic-y += preempt.h
generic-y += resource.h
generic-y += rwsem.h
generic-y += scatterlist.h
@ -45,8 +47,8 @@ generic-y += siginfo.h
generic-y += sizes.h
generic-y += socket.h
generic-y += sockios.h
generic-y += statfs.h
generic-y += stat.h
generic-y += statfs.h
generic-y += termbits.h
generic-y += termios.h
generic-y += topology.h
@ -55,4 +57,3 @@ generic-y += types.h
generic-y += ucontext.h
generic-y += unaligned.h
generic-y += xor.h
generic-y += preempt.h

View File

@ -1,8 +1,9 @@
generic-y += clkdev.h
generic-y += exec.h
generic-y += kvm_para.h
generic-y += trace_clock.h
generic-y += preempt.h
generic-y += vtime.h
generic-y += hash.h
generic-y += kvm_para.h
generic-y += mcs_spinlock.h
generic-y += preempt.h
generic-y += trace_clock.h
generic-y += vtime.h

View File

@ -1,7 +1,8 @@
generic-y += clkdev.h
generic-y += exec.h
generic-y += module.h
generic-y += trace_clock.h
generic-y += preempt.h
generic-y += hash.h
generic-y += mcs_spinlock.h
generic-y += module.h
generic-y += preempt.h
generic-y += trace_clock.h

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@ -17,6 +17,7 @@ config M68K
select FPU if MMU
select ARCH_WANT_IPC_PARSE_VERSION
select ARCH_USES_GETTIMEOFFSET if MMU && !COLDFIRE
select HAVE_FUTEX_CMPXCHG if MMU && FUTEX
select HAVE_MOD_ARCH_SPECIFIC
select MODULES_USE_ELF_REL
select MODULES_USE_ELF_RELA

View File

@ -14,8 +14,9 @@ generic-y += irq_regs.h
generic-y += kdebug.h
generic-y += kmap_types.h
generic-y += kvm_para.h
generic-y += local64.h
generic-y += local.h
generic-y += local64.h
generic-y += mcs_spinlock.h
generic-y += mman.h
generic-y += mutex.h
generic-y += percpu.h

View File

@ -13,6 +13,7 @@ generic-y += fb.h
generic-y += fcntl.h
generic-y += futex.h
generic-y += hardirq.h
generic-y += hash.h
generic-y += hw_irq.h
generic-y += ioctl.h
generic-y += ioctls.h
@ -23,6 +24,7 @@ generic-y += kmap_types.h
generic-y += kvm_para.h
generic-y += local.h
generic-y += local64.h
generic-y += mcs_spinlock.h
generic-y += msgbuf.h
generic-y += mutex.h
generic-y += param.h
@ -30,6 +32,7 @@ generic-y += pci.h
generic-y += percpu.h
generic-y += poll.h
generic-y += posix_types.h
generic-y += preempt.h
generic-y += scatterlist.h
generic-y += sections.h
generic-y += sembuf.h
@ -52,5 +55,3 @@ generic-y += unaligned.h
generic-y += user.h
generic-y += vga.h
generic-y += xor.h
generic-y += preempt.h
generic-y += hash.h

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@ -3,6 +3,7 @@ generic-y += barrier.h
generic-y += clkdev.h
generic-y += exec.h
generic-y += hash.h
generic-y += trace_clock.h
generic-y += syscalls.h
generic-y += mcs_spinlock.h
generic-y += preempt.h
generic-y += syscalls.h
generic-y += trace_clock.h

View File

@ -2,16 +2,17 @@
generic-y += cputime.h
generic-y += current.h
generic-y += emergency-restart.h
generic-y += hash.h
generic-y += local64.h
generic-y += mcs_spinlock.h
generic-y += mutex.h
generic-y += parport.h
generic-y += percpu.h
generic-y += preempt.h
generic-y += scatterlist.h
generic-y += sections.h
generic-y += segment.h
generic-y += serial.h
generic-y += trace_clock.h
generic-y += preempt.h
generic-y += ucontext.h
generic-y += xor.h
generic-y += hash.h

View File

@ -3,5 +3,6 @@ generic-y += barrier.h
generic-y += clkdev.h
generic-y += exec.h
generic-y += hash.h
generic-y += trace_clock.h
generic-y += mcs_spinlock.h
generic-y += preempt.h
generic-y += trace_clock.h

View File

@ -10,8 +10,8 @@ generic-y += bugs.h
generic-y += cacheflush.h
generic-y += checksum.h
generic-y += clkdev.h
generic-y += cmpxchg.h
generic-y += cmpxchg-local.h
generic-y += cmpxchg.h
generic-y += cputime.h
generic-y += current.h
generic-y += device.h
@ -25,6 +25,7 @@ generic-y += fcntl.h
generic-y += ftrace.h
generic-y += futex.h
generic-y += hardirq.h
generic-y += hash.h
generic-y += hw_irq.h
generic-y += ioctl.h
generic-y += ioctls.h
@ -34,6 +35,7 @@ generic-y += kdebug.h
generic-y += kmap_types.h
generic-y += kvm_para.h
generic-y += local.h
generic-y += mcs_spinlock.h
generic-y += mman.h
generic-y += module.h
generic-y += msgbuf.h
@ -41,6 +43,7 @@ generic-y += pci.h
generic-y += percpu.h
generic-y += poll.h
generic-y += posix_types.h
generic-y += preempt.h
generic-y += resource.h
generic-y += scatterlist.h
generic-y += sections.h
@ -53,11 +56,11 @@ generic-y += siginfo.h
generic-y += signal.h
generic-y += socket.h
generic-y += sockios.h
generic-y += statfs.h
generic-y += stat.h
generic-y += statfs.h
generic-y += string.h
generic-y += switch_to.h
generic-y += swab.h
generic-y += switch_to.h
generic-y += termbits.h
generic-y += termios.h
generic-y += topology.h
@ -68,5 +71,3 @@ generic-y += user.h
generic-y += vga.h
generic-y += word-at-a-time.h
generic-y += xor.h
generic-y += preempt.h
generic-y += hash.h

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@ -1,9 +1,29 @@
generic-y += auxvec.h
generic-y += barrier.h
generic-y += word-at-a-time.h auxvec.h user.h cputime.h emergency-restart.h \
segment.h topology.h vga.h device.h percpu.h hw_irq.h mutex.h \
div64.h irq_regs.h kdebug.h kvm_para.h local64.h local.h param.h \
poll.h xor.h clkdev.h exec.h
generic-y += trace_clock.h
generic-y += preempt.h
generic-y += clkdev.h
generic-y += cputime.h
generic-y += device.h
generic-y += div64.h
generic-y += emergency-restart.h
generic-y += exec.h
generic-y += hash.h
generic-y += hw_irq.h
generic-y += irq_regs.h
generic-y += kdebug.h
generic-y += kvm_para.h
generic-y += local.h
generic-y += local64.h
generic-y += mcs_spinlock.h
generic-y += mutex.h
generic-y += param.h
generic-y += percpu.h
generic-y += poll.h
generic-y += preempt.h
generic-y += segment.h
generic-y += topology.h
generic-y += trace_clock.h
generic-y += user.h
generic-y += vga.h
generic-y += word-at-a-time.h
generic-y += xor.h

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@ -1,7 +1,8 @@
generic-y += clkdev.h
generic-y += hash.h
generic-y += mcs_spinlock.h
generic-y += preempt.h
generic-y += rwsem.h
generic-y += trace_clock.h
generic-y += preempt.h
generic-y += vtime.h
generic-y += hash.h

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@ -117,6 +117,7 @@ config S390
select HAVE_FUNCTION_GRAPH_TRACER
select HAVE_FUNCTION_TRACER
select HAVE_FUNCTION_TRACE_MCOUNT_TEST
select HAVE_FUTEX_CMPXCHG if FUTEX
select HAVE_KERNEL_BZIP2
select HAVE_KERNEL_GZIP
select HAVE_KERNEL_LZ4

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@ -1,6 +1,7 @@
generic-y += clkdev.h
generic-y += trace_clock.h
generic-y += preempt.h
generic-y += hash.h
generic-y += mcs_spinlock.h
generic-y += preempt.h
generic-y += trace_clock.h

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@ -1,10 +1,11 @@
header-y +=
generic-y += barrier.h
generic-y += clkdev.h
generic-y += hash.h
generic-y += mcs_spinlock.h
generic-y += preempt.h
generic-y += trace_clock.h
generic-y += xor.h
generic-y += preempt.h

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@ -8,18 +8,21 @@ generic-y += emergency-restart.h
generic-y += errno.h
generic-y += exec.h
generic-y += fcntl.h
generic-y += hash.h
generic-y += ioctl.h
generic-y += ipcbuf.h
generic-y += irq_regs.h
generic-y += kvm_para.h
generic-y += local.h
generic-y += local64.h
generic-y += mcs_spinlock.h
generic-y += mman.h
generic-y += msgbuf.h
generic-y += param.h
generic-y += parport.h
generic-y += percpu.h
generic-y += poll.h
generic-y += mman.h
generic-y += msgbuf.h
generic-y += preempt.h
generic-y += resource.h
generic-y += scatterlist.h
generic-y += sembuf.h
@ -34,5 +37,3 @@ generic-y += termios.h
generic-y += trace_clock.h
generic-y += ucontext.h
generic-y += xor.h
generic-y += preempt.h
generic-y += hash.h

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@ -6,15 +6,16 @@ generic-y += cputime.h
generic-y += div64.h
generic-y += emergency-restart.h
generic-y += exec.h
generic-y += linkage.h
generic-y += local64.h
generic-y += mutex.h
generic-y += hash.h
generic-y += irq_regs.h
generic-y += linkage.h
generic-y += local.h
generic-y += local64.h
generic-y += mcs_spinlock.h
generic-y += module.h
generic-y += mutex.h
generic-y += preempt.h
generic-y += serial.h
generic-y += trace_clock.h
generic-y += types.h
generic-y += word-at-a-time.h
generic-y += preempt.h
generic-y += hash.h

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@ -11,6 +11,7 @@ generic-y += errno.h
generic-y += exec.h
generic-y += fb.h
generic-y += fcntl.h
generic-y += hash.h
generic-y += hw_irq.h
generic-y += ioctl.h
generic-y += ioctls.h
@ -18,12 +19,14 @@ generic-y += ipcbuf.h
generic-y += irq_regs.h
generic-y += local.h
generic-y += local64.h
generic-y += mcs_spinlock.h
generic-y += msgbuf.h
generic-y += mutex.h
generic-y += param.h
generic-y += parport.h
generic-y += poll.h
generic-y += posix_types.h
generic-y += preempt.h
generic-y += resource.h
generic-y += scatterlist.h
generic-y += sembuf.h
@ -38,5 +41,3 @@ generic-y += termios.h
generic-y += trace_clock.h
generic-y += types.h
generic-y += xor.h
generic-y += preempt.h
generic-y += hash.h

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@ -1,8 +1,28 @@
generic-y += bug.h cputime.h device.h emergency-restart.h futex.h hardirq.h
generic-y += hw_irq.h irq_regs.h kdebug.h percpu.h sections.h topology.h xor.h
generic-y += ftrace.h pci.h io.h param.h delay.h mutex.h current.h exec.h
generic-y += switch_to.h clkdev.h
generic-y += trace_clock.h
generic-y += preempt.h
generic-y += hash.h
generic-y += barrier.h
generic-y += bug.h
generic-y += clkdev.h
generic-y += cputime.h
generic-y += current.h
generic-y += delay.h
generic-y += device.h
generic-y += emergency-restart.h
generic-y += exec.h
generic-y += ftrace.h
generic-y += futex.h
generic-y += hardirq.h
generic-y += hash.h
generic-y += hw_irq.h
generic-y += io.h
generic-y += irq_regs.h
generic-y += kdebug.h
generic-y += mcs_spinlock.h
generic-y += mutex.h
generic-y += param.h
generic-y += pci.h
generic-y += percpu.h
generic-y += preempt.h
generic-y += sections.h
generic-y += switch_to.h
generic-y += topology.h
generic-y += trace_clock.h
generic-y += xor.h

View File

@ -16,6 +16,7 @@ generic-y += fcntl.h
generic-y += ftrace.h
generic-y += futex.h
generic-y += hardirq.h
generic-y += hash.h
generic-y += hw_irq.h
generic-y += ioctl.h
generic-y += ioctls.h
@ -24,6 +25,7 @@ generic-y += irq_regs.h
generic-y += kdebug.h
generic-y += kmap_types.h
generic-y += local.h
generic-y += mcs_spinlock.h
generic-y += mman.h
generic-y += module.h
generic-y += msgbuf.h
@ -32,6 +34,7 @@ generic-y += parport.h
generic-y += percpu.h
generic-y += poll.h
generic-y += posix_types.h
generic-y += preempt.h
generic-y += resource.h
generic-y += scatterlist.h
generic-y += sections.h
@ -60,5 +63,3 @@ generic-y += unaligned.h
generic-y += user.h
generic-y += vga.h
generic-y += xor.h
generic-y += preempt.h
generic-y += hash.h

View File

@ -5,3 +5,4 @@ genhdr-y += unistd_64.h
genhdr-y += unistd_x32.h
generic-y += clkdev.h
generic-y += mcs_spinlock.h

View File

@ -9,6 +9,7 @@ generic-y += errno.h
generic-y += exec.h
generic-y += fcntl.h
generic-y += hardirq.h
generic-y += hash.h
generic-y += ioctl.h
generic-y += irq_regs.h
generic-y += kdebug.h
@ -17,7 +18,9 @@ generic-y += kvm_para.h
generic-y += linkage.h
generic-y += local.h
generic-y += local64.h
generic-y += mcs_spinlock.h
generic-y += percpu.h
generic-y += preempt.h
generic-y += resource.h
generic-y += scatterlist.h
generic-y += sections.h
@ -27,5 +30,3 @@ generic-y += termios.h
generic-y += topology.h
generic-y += trace_clock.h
generic-y += xor.h
generic-y += preempt.h
generic-y += hash.h

View File

@ -39,17 +39,10 @@
lock_acquire(&(l)->dep_map, s, t, r, c, n, i)
# define __rel(l, n, i) \
lock_release(&(l)->dep_map, n, i)
# ifdef CONFIG_PROVE_LOCKING
# define lockdep_acquire(l, s, t, i) __acq(l, s, t, 0, 2, NULL, i)
# define lockdep_acquire_nest(l, s, t, n, i) __acq(l, s, t, 0, 2, n, i)
# define lockdep_acquire_read(l, s, t, i) __acq(l, s, t, 1, 2, NULL, i)
# define lockdep_release(l, n, i) __rel(l, n, i)
# else
# define lockdep_acquire(l, s, t, i) __acq(l, s, t, 0, 1, NULL, i)
# define lockdep_acquire_nest(l, s, t, n, i) __acq(l, s, t, 0, 1, n, i)
# define lockdep_acquire_read(l, s, t, i) __acq(l, s, t, 1, 1, NULL, i)
# define lockdep_release(l, n, i) __rel(l, n, i)
# endif
#define lockdep_acquire(l, s, t, i) __acq(l, s, t, 0, 1, NULL, i)
#define lockdep_acquire_nest(l, s, t, n, i) __acq(l, s, t, 0, 1, n, i)
#define lockdep_acquire_read(l, s, t, i) __acq(l, s, t, 1, 1, NULL, i)
#define lockdep_release(l, n, i) __rel(l, n, i)
#else
# define lockdep_acquire(l, s, t, i) do { } while (0)
# define lockdep_acquire_nest(l, s, t, n, i) do { } while (0)

View File

@ -0,0 +1,13 @@
#ifndef __ASM_MCS_SPINLOCK_H
#define __ASM_MCS_SPINLOCK_H
/*
* Architectures can define their own:
*
* arch_mcs_spin_lock_contended(l)
* arch_mcs_spin_unlock_contended(l)
*
* See kernel/locking/mcs_spinlock.c.
*/
#endif /* __ASM_MCS_SPINLOCK_H */

View File

@ -55,7 +55,11 @@ union futex_key {
#ifdef CONFIG_FUTEX
extern void exit_robust_list(struct task_struct *curr);
extern void exit_pi_state_list(struct task_struct *curr);
#ifdef CONFIG_HAVE_FUTEX_CMPXCHG
#define futex_cmpxchg_enabled 1
#else
extern int futex_cmpxchg_enabled;
#endif
#else
static inline void exit_robust_list(struct task_struct *curr)
{

View File

@ -252,9 +252,9 @@ struct held_lock {
unsigned int trylock:1; /* 16 bits */
unsigned int read:2; /* see lock_acquire() comment */
unsigned int check:2; /* see lock_acquire() comment */
unsigned int check:1; /* see lock_acquire() comment */
unsigned int hardirqs_off:1;
unsigned int references:11; /* 32 bits */
unsigned int references:12; /* 32 bits */
};
/*
@ -303,7 +303,7 @@ extern void lockdep_init_map(struct lockdep_map *lock, const char *name,
(lock)->dep_map.key, sub)
#define lockdep_set_novalidate_class(lock) \
lockdep_set_class(lock, &__lockdep_no_validate__)
lockdep_set_class_and_name(lock, &__lockdep_no_validate__, #lock)
/*
* Compare locking classes
*/
@ -326,9 +326,8 @@ static inline int lockdep_match_key(struct lockdep_map *lock,
*
* Values for check:
*
* 0: disabled
* 1: simple checks (freeing, held-at-exit-time, etc.)
* 2: full validation
* 0: simple checks (freeing, held-at-exit-time, etc.)
* 1: full validation
*/
extern void lock_acquire(struct lockdep_map *lock, unsigned int subclass,
int trylock, int read, int check,
@ -479,15 +478,9 @@ static inline void print_irqtrace_events(struct task_struct *curr)
* on the per lock-class debug mode:
*/
#ifdef CONFIG_PROVE_LOCKING
#define lock_acquire_exclusive(l, s, t, n, i) lock_acquire(l, s, t, 0, 2, n, i)
#define lock_acquire_shared(l, s, t, n, i) lock_acquire(l, s, t, 1, 2, n, i)
#define lock_acquire_shared_recursive(l, s, t, n, i) lock_acquire(l, s, t, 2, 2, n, i)
#else
#define lock_acquire_exclusive(l, s, t, n, i) lock_acquire(l, s, t, 0, 1, n, i)
#define lock_acquire_shared(l, s, t, n, i) lock_acquire(l, s, t, 1, 1, n, i)
#define lock_acquire_shared_recursive(l, s, t, n, i) lock_acquire(l, s, t, 2, 1, n, i)
#endif
#define lock_acquire_exclusive(l, s, t, n, i) lock_acquire(l, s, t, 0, 1, n, i)
#define lock_acquire_shared(l, s, t, n, i) lock_acquire(l, s, t, 1, 1, n, i)
#define lock_acquire_shared_recursive(l, s, t, n, i) lock_acquire(l, s, t, 2, 1, n, i)
#define spin_acquire(l, s, t, i) lock_acquire_exclusive(l, s, t, NULL, i)
#define spin_acquire_nest(l, s, t, n, i) lock_acquire_exclusive(l, s, t, n, i)
@ -518,13 +511,13 @@ static inline void print_irqtrace_events(struct task_struct *curr)
# define might_lock(lock) \
do { \
typecheck(struct lockdep_map *, &(lock)->dep_map); \
lock_acquire(&(lock)->dep_map, 0, 0, 0, 2, NULL, _THIS_IP_); \
lock_acquire(&(lock)->dep_map, 0, 0, 0, 1, NULL, _THIS_IP_); \
lock_release(&(lock)->dep_map, 0, _THIS_IP_); \
} while (0)
# define might_lock_read(lock) \
do { \
typecheck(struct lockdep_map *, &(lock)->dep_map); \
lock_acquire(&(lock)->dep_map, 0, 0, 1, 2, NULL, _THIS_IP_); \
lock_acquire(&(lock)->dep_map, 0, 0, 1, 1, NULL, _THIS_IP_); \
lock_release(&(lock)->dep_map, 0, _THIS_IP_); \
} while (0)
#else

View File

@ -46,6 +46,7 @@
* - detects multi-task circular deadlocks and prints out all affected
* locks and tasks (and only those tasks)
*/
struct optimistic_spin_queue;
struct mutex {
/* 1: unlocked, 0: locked, negative: locked, possible waiters */
atomic_t count;
@ -55,7 +56,7 @@ struct mutex {
struct task_struct *owner;
#endif
#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
void *spin_mlock; /* Spinner MCS lock */
struct optimistic_spin_queue *osq; /* Spinner MCS lock */
#endif
#ifdef CONFIG_DEBUG_MUTEXES
const char *name;
@ -179,4 +180,4 @@ extern int atomic_dec_and_mutex_lock(atomic_t *cnt, struct mutex *lock);
# define arch_mutex_cpu_relax() cpu_relax()
#endif
#endif
#endif /* __LINUX_MUTEX_H */

View File

@ -314,7 +314,7 @@ static inline bool rcu_lockdep_current_cpu_online(void)
static inline void rcu_lock_acquire(struct lockdep_map *map)
{
lock_acquire(map, 0, 0, 2, 1, NULL, _THIS_IP_);
lock_acquire(map, 0, 0, 2, 0, NULL, _THIS_IP_);
}
static inline void rcu_lock_release(struct lockdep_map *map)

View File

@ -1387,6 +1387,13 @@ config FUTEX
support for "fast userspace mutexes". The resulting kernel may not
run glibc-based applications correctly.
config HAVE_FUTEX_CMPXCHG
bool
help
Architectures should select this if futex_atomic_cmpxchg_inatomic()
is implemented and always working. This removes a couple of runtime
checks.
config EPOLL
bool "Enable eventpoll support" if EXPERT
default y

View File

@ -157,7 +157,9 @@
* enqueue.
*/
#ifndef CONFIG_HAVE_FUTEX_CMPXCHG
int __read_mostly futex_cmpxchg_enabled;
#endif
/*
* Futex flags used to encode options to functions and preserve them across
@ -2875,9 +2877,28 @@ SYSCALL_DEFINE6(futex, u32 __user *, uaddr, int, op, u32, val,
return do_futex(uaddr, op, val, tp, uaddr2, val2, val3);
}
static void __init futex_detect_cmpxchg(void)
{
#ifndef CONFIG_HAVE_FUTEX_CMPXCHG
u32 curval;
/*
* This will fail and we want it. Some arch implementations do
* runtime detection of the futex_atomic_cmpxchg_inatomic()
* functionality. We want to know that before we call in any
* of the complex code paths. Also we want to prevent
* registration of robust lists in that case. NULL is
* guaranteed to fault and we get -EFAULT on functional
* implementation, the non-functional ones will return
* -ENOSYS.
*/
if (cmpxchg_futex_value_locked(&curval, NULL, 0, 0) == -EFAULT)
futex_cmpxchg_enabled = 1;
#endif
}
static int __init futex_init(void)
{
u32 curval;
unsigned int futex_shift;
unsigned long i;
@ -2893,18 +2914,8 @@ static int __init futex_init(void)
&futex_shift, NULL,
futex_hashsize, futex_hashsize);
futex_hashsize = 1UL << futex_shift;
/*
* This will fail and we want it. Some arch implementations do
* runtime detection of the futex_atomic_cmpxchg_inatomic()
* functionality. We want to know that before we call in any
* of the complex code paths. Also we want to prevent
* registration of robust lists in that case. NULL is
* guaranteed to fault and we get -EFAULT on functional
* implementation, the non-functional ones will return
* -ENOSYS.
*/
if (cmpxchg_futex_value_locked(&curval, NULL, 0, 0) == -EFAULT)
futex_cmpxchg_enabled = 1;
futex_detect_cmpxchg();
for (i = 0; i < futex_hashsize; i++) {
atomic_set(&futex_queues[i].waiters, 0);

View File

@ -1,5 +1,5 @@
obj-y += mutex.o semaphore.o rwsem.o lglock.o
obj-y += mutex.o semaphore.o rwsem.o lglock.o mcs_spinlock.o
ifdef CONFIG_FUNCTION_TRACER
CFLAGS_REMOVE_lockdep.o = -pg

View File

@ -1936,12 +1936,12 @@ check_prevs_add(struct task_struct *curr, struct held_lock *next)
for (;;) {
int distance = curr->lockdep_depth - depth + 1;
hlock = curr->held_locks + depth-1;
hlock = curr->held_locks + depth - 1;
/*
* Only non-recursive-read entries get new dependencies
* added:
*/
if (hlock->read != 2) {
if (hlock->read != 2 && hlock->check) {
if (!check_prev_add(curr, hlock, next,
distance, trylock_loop))
return 0;
@ -2098,7 +2098,7 @@ static int validate_chain(struct task_struct *curr, struct lockdep_map *lock,
* (If lookup_chain_cache() returns with 1 it acquires
* graph_lock for us)
*/
if (!hlock->trylock && (hlock->check == 2) &&
if (!hlock->trylock && hlock->check &&
lookup_chain_cache(curr, hlock, chain_key)) {
/*
* Check whether last held lock:
@ -2517,7 +2517,7 @@ mark_held_locks(struct task_struct *curr, enum mark_type mark)
BUG_ON(usage_bit >= LOCK_USAGE_STATES);
if (hlock_class(hlock)->key == __lockdep_no_validate__.subkeys)
if (!hlock->check)
continue;
if (!mark_lock(curr, hlock, usage_bit))
@ -3055,9 +3055,6 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
int class_idx;
u64 chain_key;
if (!prove_locking)
check = 1;
if (unlikely(!debug_locks))
return 0;
@ -3069,8 +3066,8 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
if (DEBUG_LOCKS_WARN_ON(!irqs_disabled()))
return 0;
if (lock->key == &__lockdep_no_validate__)
check = 1;
if (!prove_locking || lock->key == &__lockdep_no_validate__)
check = 0;
if (subclass < NR_LOCKDEP_CACHING_CLASSES)
class = lock->class_cache[subclass];
@ -3138,7 +3135,7 @@ static int __lock_acquire(struct lockdep_map *lock, unsigned int subclass,
hlock->holdtime_stamp = lockstat_clock();
#endif
if (check == 2 && !mark_irqflags(curr, hlock))
if (check && !mark_irqflags(curr, hlock))
return 0;
/* mark it as used: */

View File

@ -0,0 +1,178 @@
#include <linux/percpu.h>
#include <linux/mutex.h>
#include <linux/sched.h>
#include "mcs_spinlock.h"
#ifdef CONFIG_SMP
/*
* An MCS like lock especially tailored for optimistic spinning for sleeping
* lock implementations (mutex, rwsem, etc).
*
* Using a single mcs node per CPU is safe because sleeping locks should not be
* called from interrupt context and we have preemption disabled while
* spinning.
*/
static DEFINE_PER_CPU_SHARED_ALIGNED(struct optimistic_spin_queue, osq_node);
/*
* Get a stable @node->next pointer, either for unlock() or unqueue() purposes.
* Can return NULL in case we were the last queued and we updated @lock instead.
*/
static inline struct optimistic_spin_queue *
osq_wait_next(struct optimistic_spin_queue **lock,
struct optimistic_spin_queue *node,
struct optimistic_spin_queue *prev)
{
struct optimistic_spin_queue *next = NULL;
for (;;) {
if (*lock == node && cmpxchg(lock, node, prev) == node) {
/*
* We were the last queued, we moved @lock back. @prev
* will now observe @lock and will complete its
* unlock()/unqueue().
*/
break;
}
/*
* We must xchg() the @node->next value, because if we were to
* leave it in, a concurrent unlock()/unqueue() from
* @node->next might complete Step-A and think its @prev is
* still valid.
*
* If the concurrent unlock()/unqueue() wins the race, we'll
* wait for either @lock to point to us, through its Step-B, or
* wait for a new @node->next from its Step-C.
*/
if (node->next) {
next = xchg(&node->next, NULL);
if (next)
break;
}
arch_mutex_cpu_relax();
}
return next;
}
bool osq_lock(struct optimistic_spin_queue **lock)
{
struct optimistic_spin_queue *node = this_cpu_ptr(&osq_node);
struct optimistic_spin_queue *prev, *next;
node->locked = 0;
node->next = NULL;
node->prev = prev = xchg(lock, node);
if (likely(prev == NULL))
return true;
ACCESS_ONCE(prev->next) = node;
/*
* Normally @prev is untouchable after the above store; because at that
* moment unlock can proceed and wipe the node element from stack.
*
* However, since our nodes are static per-cpu storage, we're
* guaranteed their existence -- this allows us to apply
* cmpxchg in an attempt to undo our queueing.
*/
while (!smp_load_acquire(&node->locked)) {
/*
* If we need to reschedule bail... so we can block.
*/
if (need_resched())
goto unqueue;
arch_mutex_cpu_relax();
}
return true;
unqueue:
/*
* Step - A -- stabilize @prev
*
* Undo our @prev->next assignment; this will make @prev's
* unlock()/unqueue() wait for a next pointer since @lock points to us
* (or later).
*/
for (;;) {
if (prev->next == node &&
cmpxchg(&prev->next, node, NULL) == node)
break;
/*
* We can only fail the cmpxchg() racing against an unlock(),
* in which case we should observe @node->locked becomming
* true.
*/
if (smp_load_acquire(&node->locked))
return true;
arch_mutex_cpu_relax();
/*
* Or we race against a concurrent unqueue()'s step-B, in which
* case its step-C will write us a new @node->prev pointer.
*/
prev = ACCESS_ONCE(node->prev);
}
/*
* Step - B -- stabilize @next
*
* Similar to unlock(), wait for @node->next or move @lock from @node
* back to @prev.
*/
next = osq_wait_next(lock, node, prev);
if (!next)
return false;
/*
* Step - C -- unlink
*
* @prev is stable because its still waiting for a new @prev->next
* pointer, @next is stable because our @node->next pointer is NULL and
* it will wait in Step-A.
*/
ACCESS_ONCE(next->prev) = prev;
ACCESS_ONCE(prev->next) = next;
return false;
}
void osq_unlock(struct optimistic_spin_queue **lock)
{
struct optimistic_spin_queue *node = this_cpu_ptr(&osq_node);
struct optimistic_spin_queue *next;
/*
* Fast path for the uncontended case.
*/
if (likely(cmpxchg(lock, node, NULL) == node))
return;
/*
* Second most likely case.
*/
next = xchg(&node->next, NULL);
if (next) {
ACCESS_ONCE(next->locked) = 1;
return;
}
next = osq_wait_next(lock, node, NULL);
if (next)
ACCESS_ONCE(next->locked) = 1;
}
#endif

View File

@ -0,0 +1,129 @@
/*
* MCS lock defines
*
* This file contains the main data structure and API definitions of MCS lock.
*
* The MCS lock (proposed by Mellor-Crummey and Scott) is a simple spin-lock
* with the desirable properties of being fair, and with each cpu trying
* to acquire the lock spinning on a local variable.
* It avoids expensive cache bouncings that common test-and-set spin-lock
* implementations incur.
*/
#ifndef __LINUX_MCS_SPINLOCK_H
#define __LINUX_MCS_SPINLOCK_H
#include <asm/mcs_spinlock.h>
struct mcs_spinlock {
struct mcs_spinlock *next;
int locked; /* 1 if lock acquired */
};
#ifndef arch_mcs_spin_lock_contended
/*
* Using smp_load_acquire() provides a memory barrier that ensures
* subsequent operations happen after the lock is acquired.
*/
#define arch_mcs_spin_lock_contended(l) \
do { \
while (!(smp_load_acquire(l))) \
arch_mutex_cpu_relax(); \
} while (0)
#endif
#ifndef arch_mcs_spin_unlock_contended
/*
* smp_store_release() provides a memory barrier to ensure all
* operations in the critical section has been completed before
* unlocking.
*/
#define arch_mcs_spin_unlock_contended(l) \
smp_store_release((l), 1)
#endif
/*
* Note: the smp_load_acquire/smp_store_release pair is not
* sufficient to form a full memory barrier across
* cpus for many architectures (except x86) for mcs_unlock and mcs_lock.
* For applications that need a full barrier across multiple cpus
* with mcs_unlock and mcs_lock pair, smp_mb__after_unlock_lock() should be
* used after mcs_lock.
*/
/*
* In order to acquire the lock, the caller should declare a local node and
* pass a reference of the node to this function in addition to the lock.
* If the lock has already been acquired, then this will proceed to spin
* on this node->locked until the previous lock holder sets the node->locked
* in mcs_spin_unlock().
*
* We don't inline mcs_spin_lock() so that perf can correctly account for the
* time spent in this lock function.
*/
static inline
void mcs_spin_lock(struct mcs_spinlock **lock, struct mcs_spinlock *node)
{
struct mcs_spinlock *prev;
/* Init node */
node->locked = 0;
node->next = NULL;
prev = xchg(lock, node);
if (likely(prev == NULL)) {
/*
* Lock acquired, don't need to set node->locked to 1. Threads
* only spin on its own node->locked value for lock acquisition.
* However, since this thread can immediately acquire the lock
* and does not proceed to spin on its own node->locked, this
* value won't be used. If a debug mode is needed to
* audit lock status, then set node->locked value here.
*/
return;
}
ACCESS_ONCE(prev->next) = node;
/* Wait until the lock holder passes the lock down. */
arch_mcs_spin_lock_contended(&node->locked);
}
/*
* Releases the lock. The caller should pass in the corresponding node that
* was used to acquire the lock.
*/
static inline
void mcs_spin_unlock(struct mcs_spinlock **lock, struct mcs_spinlock *node)
{
struct mcs_spinlock *next = ACCESS_ONCE(node->next);
if (likely(!next)) {
/*
* Release the lock by setting it to NULL
*/
if (likely(cmpxchg(lock, node, NULL) == node))
return;
/* Wait until the next pointer is set */
while (!(next = ACCESS_ONCE(node->next)))
arch_mutex_cpu_relax();
}
/* Pass lock to next waiter. */
arch_mcs_spin_unlock_contended(&next->locked);
}
/*
* Cancellable version of the MCS lock above.
*
* Intended for adaptive spinning of sleeping locks:
* mutex_lock()/rwsem_down_{read,write}() etc.
*/
struct optimistic_spin_queue {
struct optimistic_spin_queue *next, *prev;
int locked; /* 1 if lock acquired */
};
extern bool osq_lock(struct optimistic_spin_queue **lock);
extern void osq_unlock(struct optimistic_spin_queue **lock);
#endif /* __LINUX_MCS_SPINLOCK_H */

View File

@ -83,6 +83,12 @@ void debug_mutex_unlock(struct mutex *lock)
DEBUG_LOCKS_WARN_ON(!lock->wait_list.prev && !lock->wait_list.next);
mutex_clear_owner(lock);
/*
* __mutex_slowpath_needs_to_unlock() is explicitly 0 for debug
* mutexes so that we can do it here after we've verified state.
*/
atomic_set(&lock->count, 1);
}
void debug_mutex_init(struct mutex *lock, const char *name,

View File

@ -25,6 +25,7 @@
#include <linux/spinlock.h>
#include <linux/interrupt.h>
#include <linux/debug_locks.h>
#include "mcs_spinlock.h"
/*
* In the DEBUG case we are using the "NULL fastpath" for mutexes,
@ -33,6 +34,13 @@
#ifdef CONFIG_DEBUG_MUTEXES
# include "mutex-debug.h"
# include <asm-generic/mutex-null.h>
/*
* Must be 0 for the debug case so we do not do the unlock outside of the
* wait_lock region. debug_mutex_unlock() will do the actual unlock in this
* case.
*/
# undef __mutex_slowpath_needs_to_unlock
# define __mutex_slowpath_needs_to_unlock() 0
#else
# include "mutex.h"
# include <asm/mutex.h>
@ -52,7 +60,7 @@ __mutex_init(struct mutex *lock, const char *name, struct lock_class_key *key)
INIT_LIST_HEAD(&lock->wait_list);
mutex_clear_owner(lock);
#ifdef CONFIG_MUTEX_SPIN_ON_OWNER
lock->spin_mlock = NULL;
lock->osq = NULL;
#endif
debug_mutex_init(lock, name, key);
@ -111,54 +119,7 @@ EXPORT_SYMBOL(mutex_lock);
* more or less simultaneously, the spinners need to acquire a MCS lock
* first before spinning on the owner field.
*
* We don't inline mspin_lock() so that perf can correctly account for the
* time spent in this lock function.
*/
struct mspin_node {
struct mspin_node *next ;
int locked; /* 1 if lock acquired */
};
#define MLOCK(mutex) ((struct mspin_node **)&((mutex)->spin_mlock))
static noinline
void mspin_lock(struct mspin_node **lock, struct mspin_node *node)
{
struct mspin_node *prev;
/* Init node */
node->locked = 0;
node->next = NULL;
prev = xchg(lock, node);
if (likely(prev == NULL)) {
/* Lock acquired */
node->locked = 1;
return;
}
ACCESS_ONCE(prev->next) = node;
smp_wmb();
/* Wait until the lock holder passes the lock down */
while (!ACCESS_ONCE(node->locked))
arch_mutex_cpu_relax();
}
static void mspin_unlock(struct mspin_node **lock, struct mspin_node *node)
{
struct mspin_node *next = ACCESS_ONCE(node->next);
if (likely(!next)) {
/*
* Release the lock by setting it to NULL
*/
if (cmpxchg(lock, node, NULL) == node)
return;
/* Wait until the next pointer is set */
while (!(next = ACCESS_ONCE(node->next)))
arch_mutex_cpu_relax();
}
ACCESS_ONCE(next->locked) = 1;
smp_wmb();
}
/*
* Mutex spinning code migrated from kernel/sched/core.c
@ -212,6 +173,9 @@ static inline int mutex_can_spin_on_owner(struct mutex *lock)
struct task_struct *owner;
int retval = 1;
if (need_resched())
return 0;
rcu_read_lock();
owner = ACCESS_ONCE(lock->owner);
if (owner)
@ -446,9 +410,11 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
if (!mutex_can_spin_on_owner(lock))
goto slowpath;
if (!osq_lock(&lock->osq))
goto slowpath;
for (;;) {
struct task_struct *owner;
struct mspin_node node;
if (use_ww_ctx && ww_ctx->acquired > 0) {
struct ww_mutex *ww;
@ -463,19 +429,16 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
* performed the optimistic spinning cannot be done.
*/
if (ACCESS_ONCE(ww->ctx))
goto slowpath;
break;
}
/*
* If there's an owner, wait for it to either
* release the lock or go to sleep.
*/
mspin_lock(MLOCK(lock), &node);
owner = ACCESS_ONCE(lock->owner);
if (owner && !mutex_spin_on_owner(lock, owner)) {
mspin_unlock(MLOCK(lock), &node);
goto slowpath;
}
if (owner && !mutex_spin_on_owner(lock, owner))
break;
if ((atomic_read(&lock->count) == 1) &&
(atomic_cmpxchg(&lock->count, 1, 0) == 1)) {
@ -488,11 +451,10 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
}
mutex_set_owner(lock);
mspin_unlock(MLOCK(lock), &node);
osq_unlock(&lock->osq);
preempt_enable();
return 0;
}
mspin_unlock(MLOCK(lock), &node);
/*
* When there's no owner, we might have preempted between the
@ -501,7 +463,7 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
* the owner complete.
*/
if (!owner && (need_resched() || rt_task(task)))
goto slowpath;
break;
/*
* The cpu_relax() call is a compiler barrier which forces
@ -511,7 +473,15 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
*/
arch_mutex_cpu_relax();
}
osq_unlock(&lock->osq);
slowpath:
/*
* If we fell out of the spin path because of need_resched(),
* reschedule now, before we try-lock the mutex. This avoids getting
* scheduled out right after we obtained the mutex.
*/
if (need_resched())
schedule_preempt_disabled();
#endif
spin_lock_mutex(&lock->wait_lock, flags);
@ -717,10 +687,6 @@ __mutex_unlock_common_slowpath(atomic_t *lock_count, int nested)
struct mutex *lock = container_of(lock_count, struct mutex, count);
unsigned long flags;
spin_lock_mutex(&lock->wait_lock, flags);
mutex_release(&lock->dep_map, nested, _RET_IP_);
debug_mutex_unlock(lock);
/*
* some architectures leave the lock unlocked in the fastpath failure
* case, others need to leave it locked. In the later case we have to
@ -729,6 +695,10 @@ __mutex_unlock_common_slowpath(atomic_t *lock_count, int nested)
if (__mutex_slowpath_needs_to_unlock())
atomic_set(&lock->count, 1);
spin_lock_mutex(&lock->wait_lock, flags);
mutex_release(&lock->dep_map, nested, _RET_IP_);
debug_mutex_unlock(lock);
if (!list_empty(&lock->wait_list)) {
/* get the first entry from the wait-list: */
struct mutex_waiter *waiter =