benchmark

2d05303a - Add warmup and benchamrk iterations for cpu userbenchmark (#1908)

Add warmup and benchamrk iterations for cpu userbenchmark (#1908) Summary: To stabilize the benchmark results of cpu userbenchmark. Also works for https://github.com/pytorch/benchmark/issues/1293 Pull Request resolved: https://github.com/pytorch/benchmark/pull/1908 Reviewed By: davidberard98 Differential Revision: D49418232 Pulled By: xuzhao9 fbshipit-source-id: b4d0aa97fa06ffaf12984fa5dece6a0d21759fe8