search for: mayhalt_threshold

...ock_paravirt.h index 9b4ac3d..41ee033 100644 --- a/kernel/locking/qspinlock_paravirt.h +++ b/kernel/locking/qspinlock_paravirt.h @@ -19,7 +19,8 @@ * native_queue_spin_unlock(). */ -#define _Q_SLOW_VAL (3U << _Q_LOCKED_OFFSET) +#define _Q_SLOW_VAL (3U << _Q_LOCKED_OFFSET) +#define MAYHALT_THRESHOLD (SPIN_THRESHOLD >> 4) /* * The vcpu_hashed is a special state that is set by the new lock holder on @@ -39,6 +40,7 @@ struct pv_node { int cpu; u8 state; + u8 mayhalt; }; /* @@ -198,6 +200,7 @@ static void pv_init_node(struct mcs_spinlock *node) pn->cpu = smp_proce...

...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 CPU is active */ +#define PV_CPU_KICKED 2 /* This CPU is being kicked */ +#define PV_CPU_HALTED -1 /* This CPU is halted */ + +/* + * Additional fields to be added to the queue node structure + * + * The...

...n pv_link_and_wait_node) and the + * the status check by the previous queue head (in pv_wait_check). + * + * See the comments on those functions to see how the races are being + * addressed. + */ + +/* + * Spin thresholds for queue spinlock + */ +#define QSPIN_THRESHOLD SPIN_THRESHOLD +#define MAYHALT_THRESHOLD 0x10 + +/* + * CPU state flags + */ +#define PV_CPU_ACTIVE 1 /* This CPU is active */ +#define PV_CPU_KICKED 2 /* This CPU is being kicked */ +#define PV_CPU_HALTED -1 /* This CPU is halted */ + +/* + * Special head node pointer value + */ +#define PV_INVALID_HEAD NULL + +/* + * Additional f...

...n pv_link_and_wait_node) and the + * the status check by the previous queue head (in pv_wait_check). + * + * See the comments on those functions to see how the races are being + * addressed. + */ + +/* + * Spin thresholds for queue spinlock + */ +#define QSPIN_THRESHOLD SPIN_THRESHOLD +#define MAYHALT_THRESHOLD 0x10 + +/* + * CPU state flags + */ +#define PV_CPU_ACTIVE 1 /* This CPU is active */ +#define PV_CPU_KICKED 2 /* This CPU is being kicked */ +#define PV_CPU_HALTED -1 /* This CPU is halted */ + +/* + * Special head node pointer value + */ +#define PV_INVALID_HEAD NULL + +/* + * Additional f...

...n pv_link_and_wait_node) and the + * the status check by the previous queue head (in pv_wait_check). + * + * See the comments on those functions to see how the races are being + * addressed. + */ + +/* + * Spin thresholds for queue spinlock + */ +#define QSPIN_THRESHOLD SPIN_THRESHOLD +#define MAYHALT_THRESHOLD 0x10 + +/* + * CPU state flags + */ +#define PV_CPU_ACTIVE 1 /* This CPU is active */ +#define PV_CPU_KICKED 2 /* This CPU is being kicked */ +#define PV_CPU_HALTED -1 /* This CPU is halted */ + +/* + * Special head node pointer value + */ +#define PV_INVALID_HEAD NULL + +/* + * Additional f...

...n pv_link_and_wait_node) and the + * the status check by the previous queue head (in pv_wait_check). + * + * See the comments on those functions to see how the races are being + * addressed. + */ + +/* + * Spin thresholds for queue spinlock + */ +#define QSPIN_THRESHOLD SPIN_THRESHOLD +#define MAYHALT_THRESHOLD 0x10 + +/* + * CPU state flags + */ +#define PV_CPU_ACTIVE 1 /* This CPU is active */ +#define PV_CPU_KICKED 2 /* This CPU is being kicked */ +#define PV_CPU_HALTED -1 /* This CPU is halted */ + +/* + * Special head node pointer value + */ +#define PV_INVALID_HEAD NULL + +/* + * Additional f...

v13->v14: - Patches 1 & 2: Add queue_spin_unlock_wait() to accommodate commit 78bff1c86 from Oleg Nesterov. - Fix the system hang problem when using PV qspinlock in an over-committed guest due to a racing condition in the pv_set_head_in_tail() function. - Increase the MAYHALT_THRESHOLD from 10 to 1024. - Change kick_cpu into a regular function pointer instead of a callee-saved function. - Change lock statistics code to use separate bits for different statistics. v12->v13: - Change patch 9 to generate separate versions of the queue_spin_lock_slowpath functions for...

v13->v14: - Patches 1 & 2: Add queue_spin_unlock_wait() to accommodate commit 78bff1c86 from Oleg Nesterov. - Fix the system hang problem when using PV qspinlock in an over-committed guest due to a racing condition in the pv_set_head_in_tail() function. - Increase the MAYHALT_THRESHOLD from 10 to 1024. - Change kick_cpu into a regular function pointer instead of a callee-saved function. - Change lock statistics code to use separate bits for different statistics. v12->v13: - Change patch 9 to generate separate versions of the queue_spin_lock_slowpath functions for...

...governors. v13->v14: - Patches 1 & 2: Add queue_spin_unlock_wait() to accommodate commit 78bff1c86 from Oleg Nesterov. - Fix the system hang problem when using PV qspinlock in an over-committed guest due to a racing condition in the pv_set_head_in_tail() function. - Increase the MAYHALT_THRESHOLD from 10 to 1024. - Change kick_cpu into a regular function pointer instead of a callee-saved function. - Change lock statistics code to use separate bits for different statistics. v12->v13: - Change patch 9 to generate separate versions of the queue_spin_lock_slowpath functions for...

...governors. v13->v14: - Patches 1 & 2: Add queue_spin_unlock_wait() to accommodate commit 78bff1c86 from Oleg Nesterov. - Fix the system hang problem when using PV qspinlock in an over-committed guest due to a racing condition in the pv_set_head_in_tail() function. - Increase the MAYHALT_THRESHOLD from 10 to 1024. - Change kick_cpu into a regular function pointer instead of a callee-saved function. - Change lock statistics code to use separate bits for different statistics. v12->v13: - Change patch 9 to generate separate versions of the queue_spin_lock_slowpath functions for...

...governors. v13->v14: - Patches 1 & 2: Add queue_spin_unlock_wait() to accommodate commit 78bff1c86 from Oleg Nesterov. - Fix the system hang problem when using PV qspinlock in an over-committed guest due to a racing condition in the pv_set_head_in_tail() function. - Increase the MAYHALT_THRESHOLD from 10 to 1024. - Change kick_cpu into a regular function pointer instead of a callee-saved function. - Change lock statistics code to use separate bits for different statistics. v12->v13: - Change patch 9 to generate separate versions of the queue_spin_lock_slowpath functions for...

...governors. v13->v14: - Patches 1 & 2: Add queue_spin_unlock_wait() to accommodate commit 78bff1c86 from Oleg Nesterov. - Fix the system hang problem when using PV qspinlock in an over-committed guest due to a racing condition in the pv_set_head_in_tail() function. - Increase the MAYHALT_THRESHOLD from 10 to 1024. - Change kick_cpu into a regular function pointer instead of a callee-saved function. - Change lock statistics code to use separate bits for different statistics. v12->v13: - Change patch 9 to generate separate versions of the queue_spin_lock_slowpath functions for...

v11->v12: - Based on PeterZ's version of the qspinlock patch (https://lkml.org/lkml/2014/6/15/63). - Incorporated many of the review comments from Konrad Wilk and Paolo Bonzini. - The pvqspinlock code is largely from my previous version with PeterZ's way of going from queue tail to head and his idea of using callee saved calls to KVM and XEN codes. v10->v11: - Use a

v11->v12: - Based on PeterZ's version of the qspinlock patch (https://lkml.org/lkml/2014/6/15/63). - Incorporated many of the review comments from Konrad Wilk and Paolo Bonzini. - The pvqspinlock code is largely from my previous version with PeterZ's way of going from queue tail to head and his idea of using callee saved calls to KVM and XEN codes. v10->v11: - Use a

v12->v13: - Change patch 9 to generate separate versions of the queue_spin_lock_slowpath functions for bare metal and PV guest. This reduces the performance impact of the PV code on bare metal systems. v11->v12: - Based on PeterZ's version of the qspinlock patch (https://lkml.org/lkml/2014/6/15/63). - Incorporated many of the review comments from Konrad Wilk and Paolo

v12->v13: - Change patch 9 to generate separate versions of the queue_spin_lock_slowpath functions for bare metal and PV guest. This reduces the performance impact of the PV code on bare metal systems. v11->v12: - Based on PeterZ's version of the qspinlock patch (https://lkml.org/lkml/2014/6/15/63). - Incorporated many of the review comments from Konrad Wilk and Paolo

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