MPS issue job003747

TitleNo default value for MPS_KEY_ARENA_SIZE
Statusclosed
Prioritynice
Assigned userGareth Rees
OrganizationRavenbrook
DescriptionChoosing the initial arena size for a VM arena is pretty much the first thing you have to do when integrating with the MPS [1], and it's not clear what the right value is. It would be nice if you didn't have to choose.

See also djbench.c [2] where there's a comment:

    /* FIXME: Why is there no default? */
AnalysisIt's necessary to choose a good value here because "the more times [the MPS] has to extend its address space, the less efficient garbage collection will become" [1] -- this is job003554.

But when job003554 is fixed, the sensible thing for the VM arena to do is to allocate the smallest possible chunk (see job003495) and then extend it as needed.
How foundinspection
Evidence[1] <http://www.ravenbrook.com/project/mps/...guide/lang.html#choosing-an-arena-class>
[2] <http://www.ravenbrook.com/project/mps/master/code/djbench.c>
Test procedureabqtest, airtest
Created byGareth Rees
Created on2014-04-08 12:00:23
Last modified byGareth Rees
Last modified on2014-10-20 17:38:12
History2014-04-08 GDR Created.

Fixes

Change Effect Date User Description
185472 closed 2014-04-11 21:15:09 Gareth Rees Default value for MPS_KEY_ARENA_SIZE makes it easier to create arenas.