summaryrefslogtreecommitdiff
path: root/rts/Capability.h
diff options
context:
space:
mode:
authorSimon Marlow <marlowsd@gmail.com>2011-12-09 10:35:46 +0000
committerSimon Marlow <marlowsd@gmail.com>2011-12-13 08:58:57 +0000
commita02eb298d3f6089e51a43307ffb37e3a8076c8fd (patch)
tree6174e46a959a2449b54e470c8b627e3ba1a277bb /rts/Capability.h
parent55d7931d7fb55865a592f91dfa65435ee2859158 (diff)
downloadhaskell-a02eb298d3f6089e51a43307ffb37e3a8076c8fd.tar.gz
New flag +RTS -qi<n>, avoid waking up idle Capabilities to do parallel GC
This is an experimental tweak to the parallel GC that avoids waking up a Capability to do parallel GC if we know that the capability has been idle for a (tunable) number of GC cycles. The idea is that if you're only using a few Capabilities, there's no point waking up the ones that aren't busy. e.g. +RTS -qi3 says "A Capability will participate in parallel GC if it was running at all since the last 3 GC cycles." Results are a bit hit and miss, and I don't completely understand why yet. Hence, for now it is turned off by default, and also not documented except in the +RTS -? output.
Diffstat (limited to 'rts/Capability.h')
-rw-r--r--rts/Capability.h3
1 files changed, 3 insertions, 0 deletions
diff --git a/rts/Capability.h b/rts/Capability.h
index a4655dd36d..f60adf9de4 100644
--- a/rts/Capability.h
+++ b/rts/Capability.h
@@ -46,6 +46,9 @@ struct Capability_ {
// catching unsafe call-ins.
rtsBool in_haskell;
+ // Has there been any activity on this Capability since the last GC?
+ nat idle;
+
// The run queue. The Task owning this Capability has exclusive
// access to its run queue, so can wake up threads without
// taking a lock, and the common path through the scheduler is