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| author | Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-16 16:49:55 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2019-09-16 16:49:55 -0700 |
| commit | c7eba51cfdf9cd1ca7ed4201b30be8b2bef15ff5 (patch) | |
| tree | 048bff0b92dc230f01b5af23cd1b5960615bd68a /arch/x86/include | |
| parent | cc9b499a1f71696054a2771aae504c53eecff31d (diff) | |
| parent | e57d143091f1c0b1a98140a4d2e63e113afb62c0 (diff) | |
Merge branch 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull locking updates from Ingo Molnar:
- improve rwsem scalability
- add uninitialized rwsem debugging check
- reduce lockdep's stacktrace memory usage and add diagnostics
- misc cleanups, code consolidation and constification
* 'locking-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
mutex: Fix up mutex_waiter usage
locking/mutex: Use mutex flags macro instead of hard code
locking/mutex: Make __mutex_owner static to mutex.c
locking/qspinlock,x86: Clarify virt_spin_lock_key
locking/rwsem: Check for operations on an uninitialized rwsem
locking/rwsem: Make handoff writer optimistically spin on owner
locking/lockdep: Report more stack trace statistics
locking/lockdep: Reduce space occupied by stack traces
stacktrace: Constify 'entries' arguments
locking/lockdep: Make it clear that what lock_class::key points at is not modified
Diffstat (limited to 'arch/x86/include')
| -rw-r--r-- | arch/x86/include/asm/qspinlock.h | 15 |
1 files changed, 15 insertions, 0 deletions
diff --git a/arch/x86/include/asm/qspinlock.h b/arch/x86/include/asm/qspinlock.h index bd5ac6cc37db..444d6fd9a6d8 100644 --- a/arch/x86/include/asm/qspinlock.h +++ b/arch/x86/include/asm/qspinlock.h @@ -63,10 +63,25 @@ static inline bool vcpu_is_preempted(long cpu) #endif #ifdef CONFIG_PARAVIRT +/* + * virt_spin_lock_key - enables (by default) the virt_spin_lock() hijack. + * + * Native (and PV wanting native due to vCPU pinning) should disable this key. + * It is done in this backwards fashion to only have a single direction change, + * which removes ordering between native_pv_spin_init() and HV setup. + */ DECLARE_STATIC_KEY_TRUE(virt_spin_lock_key); void native_pv_lock_init(void) __init; +/* + * Shortcut for the queued_spin_lock_slowpath() function that allows + * virt to hijack it. + * + * Returns: + * true - lock has been negotiated, all done; + * false - queued_spin_lock_slowpath() will do its thing. + */ #define virt_spin_lock virt_spin_lock static inline bool virt_spin_lock(struct qspinlock *lock) { |