Changes between Version 74 and Version 75 of Developer/SMP


Ignore:
Timestamp:
Apr 21, 2014, 10:55:09 PM (6 years ago)
Author:
Mayes
Comment:

/* Multiprocessor Resource Sharing Protocol - MrsP */

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  • Developer/SMP

    v74 v75  
    12701270Feature (a) prevents lower-priority threads from running in preference to the waiting higher-priority thread and stealing resources that it might want to use in the future as part of the current execution; should that stealing happen, the blocking penalty potentially suffered on access to global resources would skyrocket to untenable levels.
    12711271Feature (b), which brings in the sole welcome extent of migration in the proposed model, which is useful when higher-priority tasks running on the processor of the global resource prevent it from completing execution; in that case, the slack allowed for by local spinning on other processors where other threads are waiting, is used to speed up the completion of the execution in the global resource and therefore reduce blocking.
     1272=  Status  =
     1273
     1274
     1275This is TBD.
    12721276=  RTEMS API Changes  =
    12731277
     
    15151519After the first mutex state change in the mutex_obtain() the mutex doesn't know
    15161520directly which thread is about to block on that mutex.  Some sequences assume
    1517 exactly one executing thread in the system, which is not true on a SMP system
     1521exactly one executing thread in the system, which