diff options
Diffstat (limited to 'unsupported/Eigen/CXX11/src/Tensor/TensorDeviceThreadPool.h')
| -rw-r--r-- | unsupported/Eigen/CXX11/src/Tensor/TensorDeviceThreadPool.h | 11 |
1 files changed, 7 insertions, 4 deletions
diff --git a/unsupported/Eigen/CXX11/src/Tensor/TensorDeviceThreadPool.h b/unsupported/Eigen/CXX11/src/Tensor/TensorDeviceThreadPool.h index ca9ba402e..90fd99027 100644 --- a/unsupported/Eigen/CXX11/src/Tensor/TensorDeviceThreadPool.h +++ b/unsupported/Eigen/CXX11/src/Tensor/TensorDeviceThreadPool.h @@ -189,9 +189,11 @@ struct ThreadPoolDevice { // of blocks to be evenly dividable across threads. double block_size_f = 1.0 / CostModel::taskSize(1, cost); - Index block_size = numext::mini(n, numext::maxi<Index>(1, block_size_f)); - const Index max_block_size = - numext::mini(n, numext::maxi<Index>(1, 2 * block_size_f)); + const Index max_oversharding_factor = 4; + Index block_size = numext::mini( + n, numext::maxi<Index>(divup<Index>(n, max_oversharding_factor * numThreads()), + block_size_f)); + const Index max_block_size = numext::mini(n, 2 * block_size); if (block_align) { Index new_block_size = block_align(block_size); eigen_assert(new_block_size >= block_size); @@ -205,7 +207,8 @@ struct ThreadPoolDevice { (divup<int>(block_count, numThreads()) * numThreads()); // Now try to increase block size up to max_block_size as long as it // doesn't decrease parallel efficiency. - for (Index prev_block_count = block_count; prev_block_count > 1;) { + for (Index prev_block_count = block_count; + max_efficiency < 1.0 && prev_block_count > 1;) { // This is the next block size that divides size into a smaller number // of blocks than the current block_size. Index coarser_block_size = divup(n, prev_block_count - 1); |