Changes between Version 33 and Version 34 of processus_thread


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Timestamp:
Oct 19, 2016, 2:49:10 PM (8 years ago)
Author:
alain
Comment:

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  • processus_thread

    v33 v34  
    88== __1) Process__ ==
    99
    10 The PID (Process Identifier) is coded on 32 bits. It is unique in the system, and has a fixed format:  The 16 MSB (CXY) contain the owner cluster identifier. The  16 LSB bits (LPID) contain the local process index in owner cluster. The '''owner cluster''' is therefore defined by PID MSB bits.
     10The PID (Process Identifier) is coded on 32 bits. It is unique in the system, and has a fixed format:  The 16 MSB (CXY) contain the owner cluster identifier. The  16 LSB bits (LPID) contain the local process index in owner cluster. The '''owner cluster''' is therefore defined by the 16 MSB bits of PID.
    1111
    12 As it exists several copies of the process descriptors, ALMOS-MK defines a reference process descriptor, located in the '''reference cluster'''. The other copies are used as local caches, and ALMOS-MK must guaranty the coherence betweenl the reference and the copies.
     12As it exists several copies of the process descriptors, ALMOS-MK defines a reference process descriptor, located in the '''reference cluster'''. The other copies are used as local caches, and ALMOS-MK must guaranty the coherence between the reference and the copies.
    1313
    1414As ALMOS-MK supports process migration, the '''reference cluster''' can be different from the '''owner cluster'''. The '''owner cluster''' cannot change (because the PID is fixed), but the '''reference cluster''' can change in case of process migration.
     
    4646This 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.
    4747
    48 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.
     48In a given process, a 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.
    4949
    5050Therefore, the TH_TBL(K,P) thread table for a given process in a given clusters contains only the threads of P placed in cluster K. The set of all threads of a given process is defined by the union of all TH_TBL(K,P) for all active clusters K.