search for: pv_halt_check

...s where races can happen: + * 1) Halting of the queue head CPU (in pv_head_spin_check) and the CPU + * kicking by the lock holder in the unlock path (in pv_kick_node). + * 2) Halting of the queue node CPU (in pv_queue_spin_check) and the + * the status check by the previous queue head (in pv_halt_check). + * See the comments on those functions to see how the races are being + * addressed. + */ + +/* + * Spin threshold for queue spinlock + */ +#define QSPIN_THRESHOLD (1U<<14) +#define MAYHALT_THRESHOLD (QSPIN_THRESHOLD - 0x10) + +/* + * CPU state flags + */ +#define PV_CPU_ACTIVE 1 /* This...

v10->v11: - Use a simple test-and-set unfair lock to simplify the code, but performance may suffer a bit for large guest with many CPUs. - Take out Raghavendra KT's test results as the unfair lock changes may render some of his results invalid. - Add PV support without increasing the size of the core queue node structure. - Other minor changes to address some of the

v10->v11: - Use a simple test-and-set unfair lock to simplify the code, but performance may suffer a bit for large guest with many CPUs. - Take out Raghavendra KT's test results as the unfair lock changes may render some of his results invalid. - Add PV support without increasing the size of the core queue node structure. - Other minor changes to address some of the

v8->v9: - Integrate PeterZ's version of the queue spinlock patch with some modification: http://lkml.kernel.org/r/20140310154236.038181843 at infradead.org - Break the more complex patches into smaller ones to ease review effort. - Fix a racing condition in the PV qspinlock code. v7->v8: - Remove one unneeded atomic operation from the slowpath, thus improving

v8->v9: - Integrate PeterZ's version of the queue spinlock patch with some modification: http://lkml.kernel.org/r/20140310154236.038181843 at infradead.org - Break the more complex patches into smaller ones to ease review effort. - Fix a racing condition in the PV qspinlock code. v7->v8: - Remove one unneeded atomic operation from the slowpath, thus improving

v9->v10: - Make some minor changes to qspinlock.c to accommodate review feedback. - Change author to PeterZ for 2 of the patches. - Include Raghavendra KT's test results in patch 18. v8->v9: - Integrate PeterZ's version of the queue spinlock patch with some modification: http://lkml.kernel.org/r/20140310154236.038181843 at infradead.org - Break the more complex

v9->v10: - Make some minor changes to qspinlock.c to accommodate review feedback. - Change author to PeterZ for 2 of the patches. - Include Raghavendra KT's test results in patch 18. v8->v9: - Integrate PeterZ's version of the queue spinlock patch with some modification: http://lkml.kernel.org/r/20140310154236.038181843 at infradead.org - Break the more complex