Changes between Version 11 and Version 12 of LightweightConcurrency

Timestamp:

05/07/12 02:04:11 (13 months ago)

Author:

kc

Comment:

edits

LightweightConcurrency

@@ -19 +19 @@
 For the high-level design principle for the current scheduler, see [http://hackage.haskell.org/trac/ghc/wiki/Commentary/Rts/Scheduler Scheduler].
 
-== Controlling Parallelism ==
-
-Whatever be the concurrency model, we would like to retain the non-programmatic control over parallelism (using , just like in the current system. 
-
 == Concurrency Substrate ==
 
 The idea of the concurrency substrate is to provide a minimal set of primitives over which a variety of user-level concurrency libraries can be implemented. As such, the concurrency substrate must provide a way to create threads, a way to schedule them, and a synchronization mechanism in a multiprocessor context. 
+
+== Controlling Parallelism ==
+
+Whatever be the concurrency model, we would like to retain the non-programmatic control over parallelism (using +RTS -N), just like in the current system. Cores are system resources and hence, the control over their allocation to different processes should be a property of the context under which the programs are run. For example, in a multi-programmed environment, it might be wiser to run the programs on a fewer cores than available to avoid thrashing. At the very least, this will avoid the cases where a poorly written concurrency library would not bring down the performance of the entire system.