Changes between Version 32 and Version 33 of processus_thread

Timestamp:

Oct 11, 2016, 2:27:33 PM (8 years ago)

Author:

alain

Comment:

--

processus_thread

@@ -42 +42 @@
  * the  '''IDLE''' thread is executed when there is no other thread to execute on a core.
 
-From the point of view of scheduling, a thread can be in six states, as described in section [wiki:thead_scheduling D]. 
+From the point of view of scheduling, a thread can be in three states : RUNNING, RUNNABLE or BLOCKED. 
 
-This implementation of ALMOS-MK does not support thread migration: a thread is pinned on a given core in a given cluster. The only exception is the main thread of a process, that is automatically created by the kernel when a new process is created, and follows its owner process in case of process migration.
+This implementation of ALMOS-MK does not support thread migration: a thread created by a pthread_create() system call is pinned on a given core in a given cluster. The only exception is the main thread of a process, that is automatically created by the kernel when a new process is created, and follows its owner process in case of process migration.
 
 An user thread is identified by a fixed format TRDID identifier, coded on 32 bits : The 16 MSB bits (CXY) define the cluster where the thread has been pinned. The 16 LSB bits (LTID) define the thread local index in the local TH_TBL[K,P] of a process descriptor P in a cluster K. This LTID index is allocated by the local process descriptor when the thread is created.
@@ -76 +76 @@
 === 3.1) fork() ===
 
-The parent process P is running on a core in cluster K, and executes the fork() system call to create a new process C on a remote cluster Z that will  become the owner of the C process. ALMOS-MK creates the first C process descriptor in the same cluster as the parent cluster P, and postpone the costly remote copy of VSL and GPT from P to C, because this copy is useless in case of exec(). When the fork() system call returns, the C process owner cluster is Z, but the reference process descriptor is in cluster K. The child process and the associated main thread will be migrated to cluster Z later, when the child process makes an "exec" or any other system call. 
+The parent process P is running on a core in cluster K, and executes the fork() system call to create a new process C on a remote cluster Z, that will  become the owner of the C process. ALMOS-MK creates the first C process descriptor in the same cluster as the parent cluster P, and postpone the costly remote copy of VSL and GPT from P to C, because this copy is useless in case of exec(). When the fork() system call returns, the C process owner cluster is Z, but the reference process descriptor is in cluster K. The child process and the associated main thread will be migrated to cluster Z later, when the child process makes an "exec" or any other system call. 
 
  1. the cluster K allocates memory in K for the reference process descriptor of C, and get a pointer on this process descriptor.
  1. the cluster K ask to kernel Z to allocate a PID for the C process, and to register the process descriptor extended pointer in its PREF_TBL(Z). It uses the RPC_PROCESS_PID_ALLOC that takes the process descriptor pointer as argument and returns the PID. 
  1. after RPC completion, the kernel K initializes the C process descriptor from informations found in the P parent process descriptor. 
- 1. the kernel K creates locally the main thread of process C, and register this thread in the TH_TBL(K,P),
+ 1. the kernel K creates locally the main thread of process C, and register this thread in the TH_TBL(K,C),
  1. the kernel K register this new thread in the scheduler of the core executing the fork() system call, an return.