Changes between Version 13 and Version 14 of kernel_locks

Timestamp:

Jan 19, 2015, 8:44:53 PM (9 years ago)

Author:

alain

Comment:

--

kernel_locks

@@ -3 +3 @@
 [[PageOutline]]
 
-The [source:soft/giet_vm/giet_common/locks.c locks.c] and [source:soft/giet_vm/giet_common/locks.h locks.h] files define the functions used by the kernel to take & release  locks protecting exclusive access to shared resources. 
+The [source:soft/giet_vm/giet_common/kernel_locks.c kernel_locks.c] and [source:soft/giet_vm/giet_common/kernel_locks.h kernel_locks.h] files define the functions used by the kernel to take & release  locks protecting exclusive access to shared resources. 
 
-The GIET_VM kernel define three types of spin-lock:
+The GIET_VM kernel define three types of locks:
 
  1. The '''simple_lock_t''' implements a non-distributed spin-lock without waiting queue. 
 
- 2. The '''spin_lock_t''' implements a spin-lock with a waiting queue (based on a ticket allocator scheme), to enforce fairness and avoid live-lock situations. The GIET_LOCK_MAX_TICKET define the wrapping value for the ticket allocator. This lock must be initialised.
+ 2. The '''spin_lock_t''' implements a spin-lock with a waiting queue (based on a ticket allocator scheme), to enforce fairness and avoid live-lock situations. 
 
- 3. The '''sbt_lock_t''' spin-lock can be used when a single lock protect a unique resource shared by a large number of tasks running on a 2D mesh clusterised architecture. The lock is implemented as a Sliced Binary Tree of ''partial'' locks distributed on all cluster, and is intended to avoid contention on a single cluster when all tasks try to access the same resource.
+ 3. The '''sqt_lock_t''' spin-lock can be used when a single lock protect a unique resource shared by a large number of tasks running on a 2D mesh clusterised architecture. The lock is implemented as a Synchronisation Quad Tree (SQT) of ''partial'' spin_locks distributed on all cluster, and is intended to avoid contention on a single cluster when all tasks try to access the same resource.
 
 All the lock access functions are prefixed by "_" to remind that they can only be executed by a processor in kernel mode.
@@ -49 +49 @@
 
  === void '''_sbt_lock_init'''( sbt_lock_t*   lock ) === 
-This function allocates and initialises the Sliced Binary Tree, distributed on all clusters. The X_SIZE and Y_SIZE parameters defined in the ''hard_config.h'' file must be power of 2, with X_SIZE = Y_SIZE or X_SIZE = 2 * Y_SIZE. This function use the _remote_malloc() function, and the distributed kernel heap segments.
+This function allocates and initialises the SQT nodes, distributed on all clusters. It computes the smallest SQT covering all processors defined in the mapping. This function use the _remote_malloc() function, and the distributed kernel heap segments.
 
  === void '''_sbt_lock_acquire'''( sbt_lock_t*  lock ) ===