Changes between Version 45 and Version 46 of AppPlanSpec

Timestamp:

Jul 26, 2018, 11:43:08 AM (7 years ago)

Author:

davea

Comment:

--

AppPlanSpec

@@ -67 +67 @@
 === Fields for multicore apps ===
 
- <min_ncpus>N</min_ncpus> :: run only on hosts with at least N usable CPUs.
- <min_ncpus_phys>N</min_ncpus_phys> :: run only on with at least N usable physical CPUs
-   (older clients don't report physical CPUs, in which case we assume physical = logical/2).
- <max_threads>N</max_threads>:: If N > 1, this is a multicore app.  Use as many CPUs as are available, but no more than N.
- <nthreads>NCPUS_PHYS-1</nthreads> :: proposed syntax
- <max_threads_phys>N</max_threads_phys>:: use as many threads as there are physical CPUs, but no more than N.
+The following distinguishes between "logical" and "physical" CPUs.
+Processors with hyperthreading have two logical CPUs per physical CPUs.
+Pre-7.14 versions of the BOINC client measure and report only the number N of logical CPUs.
+For these clients, we conservatively assume that the number of physical CPUs is max(1, N/2).
+
+"Usable" refers to computing preferences,
+which allow volunteers to limit the % of CPUs (logical and physical) that can be used.
+NUL and NUP denote the number of usable logical and physical CPUs on the host.
+
+Floating-point intensive apps should express their parallelism in terms of physical CPUs,
+since pairs of logical CPUs generally share an FPU.
+VM-based apps should do so as well, since VMWare may refuse to create a VM with more than NUP threads.
+
+ <min_ncpus>N</min_ncpus> :: run only on hosts with NUL >= N.
+ <min_ncpus_phys>N</min_ncpus_phys> :: run only on hosts with NUP >= N.
+ <max_threads>N [M]</max_threads>:: Use min(N, NUL-M) logical CPUs (if not specified, M is zero).
+ <max_threads_phys>N [M]</max_threads_phys>:: Use min(N, NUP-M) physical CPUs (if not specified, M is zero).
  <nthreads_cmdline>0|1</nthreads_cmdline>:: if set, pass command-line args '''--nthreads N'''
-  to the app, where N is the number of CPUs to use
-  (the lesser of max_threads and the number of CPUs on the host).
+  to the app, where N is the number of logical CPUs to use.
  <mem_usage_base_mb>X</mem_usage_base_mb>::
- <mem_usage_per_cpu_mb>Y</mem_usage_per_cpu_mb>:: if specified, estimated memory usage (in Megabytes) is X + NY, where N is the number of CPUs used.  Pass this to the app with a '''--memory_size_mb X''' command-line arg.
+ <mem_usage_per_cpu_mb>Y</mem_usage_per_cpu_mb>:: if specified, estimated memory usage (in Megabytes) is X + NY,
+   where N is the number of CPUs used.
+   Pass this to the app with a '''--memory_size_mb X''' command-line arg.
    
-
 === Fields for GPU apps ===