[PATCH 2/4] locking/osq_lock: Turn to dynamic switch function from osq_lock/unlock.

yongli-oc posted 4 patches 2 months, 2 weeks ago
There is a newer version of this series
[PATCH 2/4] locking/osq_lock: Turn to dynamic switch function from osq_lock/unlock.
Posted by yongli-oc 2 months, 2 weeks ago
To support numa-aware osq lock, the struct optimistic_spin_queue
is accessed as three members, numa_enable, index, tail16, by union.
The size of the struct is the same as before.
If dynamic numa-ware lock enable, turns to the crossing, x_osq_lock to
check contention level and starts dynamic switch.

Signed-off-by: yongli-oc <yongli-oc@zhaoxin.com>
---
 include/linux/osq_lock.h  | 33 ++++++++++++++++++++-
 kernel/locking/osq_lock.c | 62 +++++++++++++++++++++++++++++++++++++--
 2 files changed, 91 insertions(+), 4 deletions(-)

diff --git a/include/linux/osq_lock.h b/include/linux/osq_lock.h
index ea8fb31379e3..37a7bc4ab530 100644
--- a/include/linux/osq_lock.h
+++ b/include/linux/osq_lock.h
@@ -12,14 +12,42 @@ struct optimistic_spin_queue {
 	 * Stores an encoded value of the CPU # of the tail node in the queue.
 	 * If the queue is empty, then it's set to OSQ_UNLOCKED_VAL.
 	 */
+#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
+	union {
+		atomic_t tail;
+		u32 val;
+#ifdef __LITTLE_ENDIAN
+		struct {
+			u16 tail16;
+			u8 index;
+			u8 numa_enable;
+		};
+#else
+		struct {
+			u8 numa_enable;
+			u8 index;
+			u16 tail16;
+		};
+#endif
+	};
+#else
 	atomic_t tail;
+#endif
 };
 
 #define OSQ_UNLOCKED_VAL (0)
 
 /* Init macro and function. */
+#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
+
+#define OSQ_LOCK_UNLOCKED { .tail = ATOMIC_INIT(OSQ_UNLOCKED_VAL) }
+
+#else
+
 #define OSQ_LOCK_UNLOCKED { ATOMIC_INIT(OSQ_UNLOCKED_VAL) }
 
+#endif
+
 static inline void osq_lock_init(struct optimistic_spin_queue *lock)
 {
 	atomic_set(&lock->tail, OSQ_UNLOCKED_VAL);
@@ -28,9 +56,12 @@ static inline void osq_lock_init(struct optimistic_spin_queue *lock)
 extern bool osq_lock(struct optimistic_spin_queue *lock);
 extern void osq_unlock(struct optimistic_spin_queue *lock);
 
+#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
+extern bool osq_is_locked(struct optimistic_spin_queue *lock);
+#else
 static inline bool osq_is_locked(struct optimistic_spin_queue *lock)
 {
 	return atomic_read(&lock->tail) != OSQ_UNLOCKED_VAL;
 }
-
+#endif
 #endif
diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
index 75a6f6133866..a7b516939e00 100644
--- a/kernel/locking/osq_lock.c
+++ b/kernel/locking/osq_lock.c
@@ -2,7 +2,10 @@
 #include <linux/percpu.h>
 #include <linux/sched.h>
 #include <linux/osq_lock.h>
-
+#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
+#include "numa.h"
+#include "numa_osq.h"
+#endif
 /*
  * An MCS like lock especially tailored for optimistic spinning for sleeping
  * lock implementations (mutex, rwsem, etc).
@@ -12,12 +15,34 @@
  * spinning.
  */
 
+#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
+DEFINE_PER_CPU_SHARED_ALIGNED(struct optimistic_spin_node, osq_node);
+/*
+ * We use the value 0 to represent "no CPU", thus the encoded value
+ * will be the CPU number incremented by 1.
+ */
+inline int encode_cpu(int cpu_nr)
+{
+	return cpu_nr + 1;
+}
+
+inline int node_cpu(struct optimistic_spin_node *node)
+{
+	return node->cpu - 1;
+}
+
+inline struct optimistic_spin_node *decode_cpu(int encoded_cpu_val)
+{
+	int cpu_nr = encoded_cpu_val - 1;
+
+	return per_cpu_ptr(&osq_node, cpu_nr);
+}
+#else
 struct optimistic_spin_node {
 	struct optimistic_spin_node *next, *prev;
 	int locked; /* 1 if lock acquired */
 	int cpu; /* encoded CPU # + 1 value */
 };
-
 static DEFINE_PER_CPU_SHARED_ALIGNED(struct optimistic_spin_node, osq_node);
 
 /*
@@ -40,6 +65,7 @@ static inline struct optimistic_spin_node *decode_cpu(int encoded_cpu_val)
 
 	return per_cpu_ptr(&osq_node, cpu_nr);
 }
+#endif
 
 /*
  * Get a stable @node->next pointer, either for unlock() or unqueue() purposes.
@@ -97,6 +123,14 @@ bool osq_lock(struct optimistic_spin_queue *lock)
 	int curr = encode_cpu(smp_processor_id());
 	int old;
 
+#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
+	if (unlikely(enable_zx_numa_osq_lock > 1)) {
+		node->numa = 1;
+		return x_osq_lock(lock);
+	}
+	node->numa = 0;
+#endif
+
 	node->locked = 0;
 	node->next = NULL;
 	node->cpu = curr;
@@ -108,6 +142,11 @@ bool osq_lock(struct optimistic_spin_queue *lock)
 	 * the lock tail.
 	 */
 	old = atomic_xchg(&lock->tail, curr);
+#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
+	if (enable_zx_numa_osq_lock > 0)
+	//enable means all cpu cores are less tan 65534.
+		old = old & 0xffff;
+#endif
 	if (old == OSQ_UNLOCKED_VAL)
 		return true;
 
@@ -212,6 +251,14 @@ void osq_unlock(struct optimistic_spin_queue *lock)
 	struct optimistic_spin_node *node, *next;
 	int curr = encode_cpu(smp_processor_id());
 
+	node = this_cpu_ptr(&osq_node);
+
+#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
+	if (unlikely(enable_zx_numa_osq_lock > 1 &&
+		node->numa == 1))
+		return x_osq_unlock(lock);
+#endif
+
 	/*
 	 * Fast path for the uncontended case.
 	 */
@@ -222,7 +269,6 @@ void osq_unlock(struct optimistic_spin_queue *lock)
 	/*
 	 * Second most likely case.
 	 */
-	node = this_cpu_ptr(&osq_node);
 	next = xchg(&node->next, NULL);
 	if (next) {
 		WRITE_ONCE(next->locked, 1);
@@ -233,3 +279,13 @@ void osq_unlock(struct optimistic_spin_queue *lock)
 	if (next)
 		WRITE_ONCE(next->locked, 1);
 }
+#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
+bool osq_is_locked(struct optimistic_spin_queue *lock)
+{
+	if (unlikely(enable_zx_numa_osq_lock > 1))
+		return x_osq_is_locked(lock);
+	return atomic_read(&lock->tail) != OSQ_UNLOCKED_VAL;
+}
+#endif
+
+
-- 
2.34.1
Re: [PATCH 2/4] locking/osq_lock: Turn to dynamic switch function from osq_lock/unlock.
Posted by Waiman Long 2 months, 2 weeks ago
On 9/14/24 04:53, yongli-oc wrote:
> To support numa-aware osq lock, the struct optimistic_spin_queue
> is accessed as three members, numa_enable, index, tail16, by union.
> The size of the struct is the same as before.
> If dynamic numa-ware lock enable, turns to the crossing, x_osq_lock to
> check contention level and starts dynamic switch.
>
> Signed-off-by: yongli-oc <yongli-oc@zhaoxin.com>
> ---
>   include/linux/osq_lock.h  | 33 ++++++++++++++++++++-
>   kernel/locking/osq_lock.c | 62 +++++++++++++++++++++++++++++++++++++--
>   2 files changed, 91 insertions(+), 4 deletions(-)
>
> diff --git a/include/linux/osq_lock.h b/include/linux/osq_lock.h
> index ea8fb31379e3..37a7bc4ab530 100644
> --- a/include/linux/osq_lock.h
> +++ b/include/linux/osq_lock.h
> @@ -12,14 +12,42 @@ struct optimistic_spin_queue {
>   	 * Stores an encoded value of the CPU # of the tail node in the queue.
>   	 * If the queue is empty, then it's set to OSQ_UNLOCKED_VAL.
>   	 */
> +#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
> +	union {
> +		atomic_t tail;
> +		u32 val;
> +#ifdef __LITTLE_ENDIAN
> +		struct {
> +			u16 tail16;
> +			u8 index;
> +			u8 numa_enable;
> +		};
> +#else
> +		struct {
> +			u8 numa_enable;
> +			u8 index;
> +			u16 tail16;
> +		};
> +#endif
> +	};
> +#else
>   	atomic_t tail;
> +#endif
>   };
>   
>   #define OSQ_UNLOCKED_VAL (0)
>   
>   /* Init macro and function. */
> +#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
> +
> +#define OSQ_LOCK_UNLOCKED { .tail = ATOMIC_INIT(OSQ_UNLOCKED_VAL) }
> +
> +#else
> +
>   #define OSQ_LOCK_UNLOCKED { ATOMIC_INIT(OSQ_UNLOCKED_VAL) }
>   
> +#endif
> +
>   static inline void osq_lock_init(struct optimistic_spin_queue *lock)
>   {
>   	atomic_set(&lock->tail, OSQ_UNLOCKED_VAL);
> @@ -28,9 +56,12 @@ static inline void osq_lock_init(struct optimistic_spin_queue *lock)
>   extern bool osq_lock(struct optimistic_spin_queue *lock);
>   extern void osq_unlock(struct optimistic_spin_queue *lock);
>   
> +#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
> +extern bool osq_is_locked(struct optimistic_spin_queue *lock);
> +#else
>   static inline bool osq_is_locked(struct optimistic_spin_queue *lock)
>   {
>   	return atomic_read(&lock->tail) != OSQ_UNLOCKED_VAL;
>   }
> -
> +#endif
>   #endif
> diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
> index 75a6f6133866..a7b516939e00 100644
> --- a/kernel/locking/osq_lock.c
> +++ b/kernel/locking/osq_lock.c
> @@ -2,7 +2,10 @@
>   #include <linux/percpu.h>
>   #include <linux/sched.h>
>   #include <linux/osq_lock.h>
> -
> +#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
> +#include "numa.h"
> +#include "numa_osq.h"
> +#endif

These header files are defined in patch 3. You need to rethink about 
patch ordering in order not to break bisection.


>   /*
>    * An MCS like lock especially tailored for optimistic spinning for sleeping
>    * lock implementations (mutex, rwsem, etc).
> @@ -12,12 +15,34 @@
>    * spinning.
>    */
>   
> +#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
> +DEFINE_PER_CPU_SHARED_ALIGNED(struct optimistic_spin_node, osq_node);
> +/*
> + * We use the value 0 to represent "no CPU", thus the encoded value
> + * will be the CPU number incremented by 1.
> + */
> +inline int encode_cpu(int cpu_nr)
> +{
> +	return cpu_nr + 1;
> +}
> +
> +inline int node_cpu(struct optimistic_spin_node *node)
> +{
> +	return node->cpu - 1;
> +}
> +
> +inline struct optimistic_spin_node *decode_cpu(int encoded_cpu_val)
> +{
> +	int cpu_nr = encoded_cpu_val - 1;
> +
> +	return per_cpu_ptr(&osq_node, cpu_nr);
> +}
> +#else
>   struct optimistic_spin_node {
>   	struct optimistic_spin_node *next, *prev;
>   	int locked; /* 1 if lock acquired */
>   	int cpu; /* encoded CPU # + 1 value */
>   };
> -
>   static DEFINE_PER_CPU_SHARED_ALIGNED(struct optimistic_spin_node, osq_node);
>   
>   /*
> @@ -40,6 +65,7 @@ static inline struct optimistic_spin_node *decode_cpu(int encoded_cpu_val)
>   
>   	return per_cpu_ptr(&osq_node, cpu_nr);
>   }
> +#endif
>   
>   /*
>    * Get a stable @node->next pointer, either for unlock() or unqueue() purposes.
> @@ -97,6 +123,14 @@ bool osq_lock(struct optimistic_spin_queue *lock)
>   	int curr = encode_cpu(smp_processor_id());
>   	int old;
>   
> +#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
> +	if (unlikely(enable_zx_numa_osq_lock > 1)) {
> +		node->numa = 1;
> +		return x_osq_lock(lock);
> +	}
> +	node->numa = 0;
> +#endif
> +
>   	node->locked = 0;
>   	node->next = NULL;
>   	node->cpu = curr;
> @@ -108,6 +142,11 @@ bool osq_lock(struct optimistic_spin_queue *lock)
>   	 * the lock tail.
>   	 */
>   	old = atomic_xchg(&lock->tail, curr);
> +#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
> +	if (enable_zx_numa_osq_lock > 0)
> +	//enable means all cpu cores are less tan 65534.
> +		old = old & 0xffff;
> +#endif
>   	if (old == OSQ_UNLOCKED_VAL)
>   		return true;
>   
> @@ -212,6 +251,14 @@ void osq_unlock(struct optimistic_spin_queue *lock)
>   	struct optimistic_spin_node *node, *next;
>   	int curr = encode_cpu(smp_processor_id());
>   
> +	node = this_cpu_ptr(&osq_node);
> +
> +#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
> +	if (unlikely(enable_zx_numa_osq_lock > 1 &&
> +		node->numa == 1))
> +		return x_osq_unlock(lock);
> +#endif
> +
>   	/*
>   	 * Fast path for the uncontended case.
>   	 */
> @@ -222,7 +269,6 @@ void osq_unlock(struct optimistic_spin_queue *lock)
>   	/*
>   	 * Second most likely case.
>   	 */
> -	node = this_cpu_ptr(&osq_node);
>   	next = xchg(&node->next, NULL);
>   	if (next) {
>   		WRITE_ONCE(next->locked, 1);
> @@ -233,3 +279,13 @@ void osq_unlock(struct optimistic_spin_queue *lock)
>   	if (next)
>   		WRITE_ONCE(next->locked, 1);
>   }
> +#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
> +bool osq_is_locked(struct optimistic_spin_queue *lock)
> +{
> +	if (unlikely(enable_zx_numa_osq_lock > 1))
> +		return x_osq_is_locked(lock);
> +	return atomic_read(&lock->tail) != OSQ_UNLOCKED_VAL;
> +}
> +#endif
> +
> +
Re: [PATCH 2/4] locking/osq_lock: Turn to dynamic switch function from osq_lock/unlock.
Posted by yongli-os 2 months, 1 week ago
On 2024/9/15 00:06, Waiman Long wrote:
>
>
> [这封邮件来自外部发件人 谨防风险]
>
> On 9/14/24 04:53, yongli-oc wrote:
>> To support numa-aware osq lock, the struct optimistic_spin_queue
>> is accessed as three members, numa_enable, index, tail16, by union.
>> The size of the struct is the same as before.
>> If dynamic numa-ware lock enable, turns to the crossing, x_osq_lock to
>> check contention level and starts dynamic switch.
>>
>> Signed-off-by: yongli-oc <yongli-oc@zhaoxin.com>
>> ---
>>   include/linux/osq_lock.h  | 33 ++++++++++++++++++++-
>>   kernel/locking/osq_lock.c | 62 +++++++++++++++++++++++++++++++++++++--
>>   2 files changed, 91 insertions(+), 4 deletions(-)
>>
>> diff --git a/include/linux/osq_lock.h b/include/linux/osq_lock.h
>> index ea8fb31379e3..37a7bc4ab530 100644
>> --- a/include/linux/osq_lock.h
>> +++ b/include/linux/osq_lock.h
>> @@ -12,14 +12,42 @@ struct optimistic_spin_queue {
>>        * Stores an encoded value of the CPU # of the tail node in the 
>> queue.
>>        * If the queue is empty, then it's set to OSQ_UNLOCKED_VAL.
>>        */
>> +#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
>> +     union {
>> +             atomic_t tail;
>> +             u32 val;
>> +#ifdef __LITTLE_ENDIAN
>> +             struct {
>> +                     u16 tail16;
>> +                     u8 index;
>> +                     u8 numa_enable;
>> +             };
>> +#else
>> +             struct {
>> +                     u8 numa_enable;
>> +                     u8 index;
>> +                     u16 tail16;
>> +             };
>> +#endif
>> +     };
>> +#else
>>       atomic_t tail;
>> +#endif
>>   };
>>
>>   #define OSQ_UNLOCKED_VAL (0)
>>
>>   /* Init macro and function. */
>> +#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
>> +
>> +#define OSQ_LOCK_UNLOCKED { .tail = ATOMIC_INIT(OSQ_UNLOCKED_VAL) }
>> +
>> +#else
>> +
>>   #define OSQ_LOCK_UNLOCKED { ATOMIC_INIT(OSQ_UNLOCKED_VAL) }
>>
>> +#endif
>> +
>>   static inline void osq_lock_init(struct optimistic_spin_queue *lock)
>>   {
>>       atomic_set(&lock->tail, OSQ_UNLOCKED_VAL);
>> @@ -28,9 +56,12 @@ static inline void osq_lock_init(struct 
>> optimistic_spin_queue *lock)
>>   extern bool osq_lock(struct optimistic_spin_queue *lock);
>>   extern void osq_unlock(struct optimistic_spin_queue *lock);
>>
>> +#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
>> +extern bool osq_is_locked(struct optimistic_spin_queue *lock);
>> +#else
>>   static inline bool osq_is_locked(struct optimistic_spin_queue *lock)
>>   {
>>       return atomic_read(&lock->tail) != OSQ_UNLOCKED_VAL;
>>   }
>> -
>> +#endif
>>   #endif
>> diff --git a/kernel/locking/osq_lock.c b/kernel/locking/osq_lock.c
>> index 75a6f6133866..a7b516939e00 100644
>> --- a/kernel/locking/osq_lock.c
>> +++ b/kernel/locking/osq_lock.c
>> @@ -2,7 +2,10 @@
>>   #include <linux/percpu.h>
>>   #include <linux/sched.h>
>>   #include <linux/osq_lock.h>
>> -
>> +#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
>> +#include "numa.h"
>> +#include "numa_osq.h"
>> +#endif
>
> These header files are defined in patch 3. You need to rethink about
> patch ordering in order not to break bisection.
I will move it to the patch 2.
>
>>   /*
>>    * An MCS like lock especially tailored for optimistic spinning for 
>> sleeping
>>    * lock implementations (mutex, rwsem, etc).
>> @@ -12,12 +15,34 @@
>>    * spinning.
>>    */
>>
>> +#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
>> +DEFINE_PER_CPU_SHARED_ALIGNED(struct optimistic_spin_node, osq_node);
>> +/*
>> + * We use the value 0 to represent "no CPU", thus the encoded value
>> + * will be the CPU number incremented by 1.
>> + */
>> +inline int encode_cpu(int cpu_nr)
>> +{
>> +     return cpu_nr + 1;
>> +}
>> +
>> +inline int node_cpu(struct optimistic_spin_node *node)
>> +{
>> +     return node->cpu - 1;
>> +}
>> +
>> +inline struct optimistic_spin_node *decode_cpu(int encoded_cpu_val)
>> +{
>> +     int cpu_nr = encoded_cpu_val - 1;
>> +
>> +     return per_cpu_ptr(&osq_node, cpu_nr);
>> +}
>> +#else
>>   struct optimistic_spin_node {
>>       struct optimistic_spin_node *next, *prev;
>>       int locked; /* 1 if lock acquired */
>>       int cpu; /* encoded CPU # + 1 value */
>>   };
>> -
>>   static DEFINE_PER_CPU_SHARED_ALIGNED(struct optimistic_spin_node, 
>> osq_node);
>>
>>   /*
>> @@ -40,6 +65,7 @@ static inline struct optimistic_spin_node 
>> *decode_cpu(int encoded_cpu_val)
>>
>>       return per_cpu_ptr(&osq_node, cpu_nr);
>>   }
>> +#endif
>>
>>   /*
>>    * Get a stable @node->next pointer, either for unlock() or 
>> unqueue() purposes.
>> @@ -97,6 +123,14 @@ bool osq_lock(struct optimistic_spin_queue *lock)
>>       int curr = encode_cpu(smp_processor_id());
>>       int old;
>>
>> +#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
>> +     if (unlikely(enable_zx_numa_osq_lock > 1)) {
>> +             node->numa = 1;
>> +             return x_osq_lock(lock);
>> +     }
>> +     node->numa = 0;
>> +#endif
>> +
>>       node->locked = 0;
>>       node->next = NULL;
>>       node->cpu = curr;
>> @@ -108,6 +142,11 @@ bool osq_lock(struct optimistic_spin_queue *lock)
>>        * the lock tail.
>>        */
>>       old = atomic_xchg(&lock->tail, curr);
>> +#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
>> +     if (enable_zx_numa_osq_lock > 0)
>> +     //enable means all cpu cores are less tan 65534.
>> +             old = old & 0xffff;
>> +#endif
>>       if (old == OSQ_UNLOCKED_VAL)
>>               return true;
>>
>> @@ -212,6 +251,14 @@ void osq_unlock(struct optimistic_spin_queue *lock)
>>       struct optimistic_spin_node *node, *next;
>>       int curr = encode_cpu(smp_processor_id());
>>
>> +     node = this_cpu_ptr(&osq_node);
>> +
>> +#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
>> +     if (unlikely(enable_zx_numa_osq_lock > 1 &&
>> +             node->numa == 1))
>> +             return x_osq_unlock(lock);
>> +#endif
>> +
>>       /*
>>        * Fast path for the uncontended case.
>>        */
>> @@ -222,7 +269,6 @@ void osq_unlock(struct optimistic_spin_queue *lock)
>>       /*
>>        * Second most likely case.
>>        */
>> -     node = this_cpu_ptr(&osq_node);
>>       next = xchg(&node->next, NULL);
>>       if (next) {
>>               WRITE_ONCE(next->locked, 1);
>> @@ -233,3 +279,13 @@ void osq_unlock(struct optimistic_spin_queue *lock)
>>       if (next)
>>               WRITE_ONCE(next->locked, 1);
>>   }
>> +#ifdef CONFIG_LOCK_SPIN_ON_OWNER_NUMA
>> +bool osq_is_locked(struct optimistic_spin_queue *lock)
>> +{
>> +     if (unlikely(enable_zx_numa_osq_lock > 1))
>> +             return x_osq_is_locked(lock);
>> +     return atomic_read(&lock->tail) != OSQ_UNLOCKED_VAL;
>> +}
>> +#endif
>> +
>> +
>