Changes between Version 42 and Version 43 of processus_thread


Ignore:
Timestamp:
Nov 9, 2017, 12:29:18 PM (5 years ago)
Author:
alain
Comment:

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  • processus_thread

    v42 v43  
    8282
    8383Regarding the process descriptor, a new PID must be allocated in cluster Y.  The child process C inherit the vsegs registered in the parent process reference VSL, but the ALMOS-MKH replication policy depends on the vseg type:
    84  * for the '''DATA, MMAP, REMOTE''' vsegs (containing shared, non replicated data), all vsegs registered in the parent reference VSL(Z,P) are registered in the child  reference VSL(Y,C), and all valid GPT entries in the reference parent GPT(Z,P) are copied in the child reference GPT(Y,C). For all pages, the WRITABLE flag is reset and the COW flag is set, in both (parent and child) GPTs. This require to update all replicated parent GPT copies in all cluster.
     84 * for the '''DATA, MMAP, REMOTE''' vsegs (containing shared, non replicated data), all vsegs registered in the parent reference VSL(Z,P) are registered in the child  reference VSL(Y,C), and all valid GPT entries in the reference parent GPT(Z,P) are copied in the child reference GPT(Y,C). For all pages, the WRITABLE flag is reset and the COW flag is set, in both (parent and child) GPTs. This require to invalidate all corresponding entries in the parent GPT copies (in clusters other than the reference).
    8585 * for the '''STACK''' vseg(that are private), only one vseg is registered in the child reference VSL(Y,C). This vseg contains the user stack of the user thread requesting the fork, running in cluster X. All valid GPT entries in the parent GPT(X,P) are copied in the child GPT(Y,C). For all pages, the WRITABLE flag is reset and the COW flag is set, in both (parent and child) GPTs. This require to update all replicated parent GPT copies in all cluster.
    8686 * for the '''CODE''' vsegs (that must be replicated in all clusters containing a thread), all vsegs registered in the reference parent VSL(Z,P) are registered in the child  reference VSL(Y,C), but the reference child GPT(Y,C) is not updated by the fork: It will be dynamically updated on demand in case of page fault.