Changes between Version 8 and Version 9 of AppCoprocessor


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Timestamp:
Mar 12, 2008, 2:35:41 PM (16 years ago)
Author:
davea
Comment:

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  • AppCoprocessor

    v8 v9  
    99i.e., an application using a coprocessor has it locked while the app is in memory,
    1010even if the app is suspended by BOINC or descheduled by the OS.
    11 
    12 == Proposed design ==
    1311
    1412The BOINC client probes for coprocessors and reports them in scheduler requests.
     
    2523}}}
    2624
    27 An app_version record (in the server DB) has a character string field '''class'''.
    28 
    29 The scheduler is linked with a project-supplied function
    30 {{{
    31 bool analyze_app(HOST&, char* class, HOST_USAGE&);
    32 
    33 struct HOST_USAGE {
    34    COPROCS coprocs;   // coprocessors used by the app (name and count)
    35    double ncpus;      // #CPUs used by app (may be fractional)
    36    double flops;      // estimated FLOPS
    37    char opaque[256];  // passed to the app in init_data.xml
    38 };
    39 }}}
    40 The HOST argument describes the host's CPU(s),
    41 and includes a field 'coprocs' listing its coprocessors.
    42 
    43 The function returns true if the host's resources are sufficient for the app version.
    44 If true, it populates the HOST_USAGE structure.
    45 
    46 When deciding whether to send a job to a host,
    47 the scheduler examines all latest-version app_versions for the platform,
    48 and selects the one for which flops is greatest.
    49 
    50 The scheduler reply includes, for each app version, an XML encoding of HOST_USAGE.
    51 
    52 The client keeps track of coprocessor allocation, i.e. how many instances of each are free.
    53 It only runs an app if enough instances are available.
    54 
    55 The client uses app_version.usage.flops to estimate job completion times.
    5625
    5726== Questions ==