Changes between Version 19 and Version 20 of GpuWorkFetch

Timestamp:

Dec 29, 2008, 4:00:59 PM (15 years ago)

Author:

davea

Comment:

--

GpuWorkFetch

@@ -79 +79 @@
 
 We'll continue to use the idea of '''long-term debt''' (LTD).
-LTD represents how much work is "owed" to each project.
+LTD represents how much work (measured in device instance-seconds) is "owed" to each project.
 This increases over time in proportion to its resource share,
 and decreases as it uses resources.
@@ -103 +103 @@
  * The "overall LTD", which is used in the work-fetch decision, is the sum of the resource LTDs, weighted by the speed of the resource (FLOPs per instance-second).
 
-
+Next we need to specify exactly how LTD is maintained.
+It's clear how it decreases; the question is, how is it increased?
+We need to avoid situations where LTD increases without bound.
+We propose the following:
+
+ * For each project P and resource R there is a boolean flag D(P, R) indication whether P should accumulate debt for R.  The idea is that if D(P,R) is true, then it's likely that P would supply a job for R if we asked it.
+ * D(P, R) is initially false.
+ * If P supplies a job for R, D(P,R) is set to true.
+ * If we send P a request that doesn't return any jobs, then for each resource R for which req_seconds(R)>0, D(P,R) is set to false.
 
 === Per-resource-type backoff ===