Changes between Version 6 and Version 7 of CreditNew

Author:

davea (IP: 128.32.18.181)

Timestamp:

11/03/09 14:37:20 (3 weeks ago)

Comment:

--

CreditNew

@@ -16 +16 @@
-is the ratio of actual FLOPS to peak FLOPS.
-
-G
+C
-However, application efficiency is typically lower
-(very roughly, 10% for GPUs, 50% for CPUs).
-   It's not exactly "Actual FLOPs", since the most efficient
-   version may not be 100% efficient.
+ * There are two sources of variance in PFC(V):
+   the variation in host efficiency,
+   and possibly the variation in job size.
+   If we have an ''a priori'' estimate of job size
+   (e.g., workunit.rsc_fpops_est)
+   we can normalize by this to reduce the variance,
+   and make PFC*(V) converge more quickly.
+ * ''a posteriori'' estimates of job size may exist also
+   (e.g., an iteration count reported by the app)
+   but using this for anything introduces a new cheating risk,
+   so it's probably better not to.
+
-
-== Cross-project normalization ==
-
-Assuming that hosts are sent jobs for a given app uniformly,
- for a given app
+, for that app,
-hosts should get the same average granted credit per job.
-To ensure this, for each application A we maintain the average VNPFC*(A),
-
-There are some cases where hosts are not sent jobs uniformly:
-
+ (smaller jobs sent to slower hosts)
- * GPUGrid.net's scheme for sending some (presumably larger)
-   jobs to GPUs with more processors.
-
+
+
+
+
+
+
-
-Notes:
-is
+e host normalization
-   that are less efficient than average,
-   and increases the claimed credit of hosts that are more efficient
-}}}
-
-== Jobs versus app units ==
-   To deal with this, we can weight jobs by workunit.rsc_flops_est.
-
-If a project changes between jobs to app units,
-it must reset
-
-== Cross-project scaling factors ==
-
-granted credit = claimed credit.
-
-is
+should
-set to the min of the valid results
-(min is used instead of average to remove the incentive
-== Job runtime estimates ==
-
+Unrelated to the credit proposal, but in a similar spirit.
+The server will maintain ET*(H, V), the statistics of
+job runtimes (normalized by wu.rsc_fpops_est) per
+host and application version.
+
+The server's estimate of a job's runtime is then
+{{{
+R(J, H) = wu.rsc_fpops_est * ET*(H, V)
+}}}
+
-== Implementation ==
-