diff options
| -rw-r--r-- | TODO | 1 | ||||
| -rw-r--r-- | src/run.cpp | 9 |
2 files changed, 9 insertions, 1 deletions
@@ -0,0 +1 @@ +Fix the fucked up iteration prediction when using many threads. diff --git a/src/run.cpp b/src/run.cpp index c78f89a..c3e2495 100644 --- a/src/run.cpp +++ b/src/run.cpp @@ -116,7 +116,13 @@ int Run::run() { this->exp->prefetch_hint); // calculate the number of iterations - if (this->exp->iterations <= 0) { + /* + * As soon as the thread count rises, this calculation HUGELY + * differs between runs. What does cause this? Threads are already + * limited to certain CPUs, so it's not caused by excessive switching. + * Strange cache behaviour? + */ + if (0 == this->exp->iterations) { volatile static double istart = 0; volatile static double istop = 0; volatile static double elapsed = 0; @@ -155,6 +161,7 @@ int Run::run() { } else { this->exp->iterations = std::max(1.0, 0.9999 + iters / elapsed); } + //printf("Tested %d iterations: took %f seconds; scheduling %d iterations\n", iters, elapsed, this->exp->iterations); } this->bp->barrier(); } |