Changes between Version 4 and Version 5 of ClientSched


Ignore:
Timestamp:
Dec 3, 2008, 11:38:46 AM (16 years ago)
Author:
davea
Comment:

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  • ClientSched

    v4 v5  
    11= Client scheduling policies =
     2
     3NOTE: this document is outdated because of development in the 6.4 client
     4to handle GPU and multithread apps.
     5Changes include:
     6
     70) app versions now include avg_ncpus, coprocessor usage, and
     8a FLOPS estimate (this defaults to the CPU benchmark,
     9but for GPU and multithread apps it will be different).
     10This info is sent from the server.
     11
     121) Estimating the duration of unstarted jobs:
     13jobs are now associated with specific app versions.
     14The estimated duration of an unstarted job is the WU's
     15FLOP estimate divided by the app version's FLOPS,
     16scaled by the duration correction factor.
     17
     182) Duration correction factor: this is now based on elapsed time
     19(i.e. wall time during which the job has been running) rather than CPU time.
     20Yes, this is affected by non-BOINC CPU load; that's as it should be.
     21
     223) "CPU efficiency" is no longer maintained; it's subsumed in DCF.
     23
     244) Estimating the duration of running jobs:
     25this is a weighted average of static and dynamic estimates.
     26The dynamic estimate is now based on elapsed time rather than CPU time.
     27So if a GPU job has been running for 5 min, is 25% done,
     28and has used 1 min of CPU, its dynamic estimate is 20 min (not 4 min).
     29
     305) round-robin simulation: this was modified to reflect multi-thread
     31and coproc apps (e.g., if the host has 1 GPU, only one coproc app
     32can run at a time).
     33If CPUs are idle because coprocs are in use,
     34don't count it towards CPU shortfall.
     35
     366) scheduler_cpus() and enforce_schedule() take coprocs and
     37avg_ncpus into account.  They try to keep GPUs busy if possible.
     38
     39---------------
    240
    341This document describes three related parts of the BOINC core client: