Created by: backyes

Paddle 提供了一个命令行参数 --test_period，但是其意思并不明确：

• How long period(pass) to wait until next testing?
• How many samples used for one test ?

void Tester::testOnePeriod() {
  DataBatch dataBatch;
  int64_t batchSize = config_->getOptConfig().batch_size();
  bool testAllData =
      intconfig_->testPeriod == 0 || intconfig_->testAllDataInOnePeriod;
  int batches =
      testAllData ? std::numeric_limits<int>::max() : intconfig_->testPeriod;

Here test_period indicates two meaning:

• batches used for testing
• wait N batches training passed, then do testing.

It's is confusing, and not be correct in doc： http://www.paddlepaddle.org/doc/ui/cmd_argument/detail_introduction.html?highlight=test_period

related issue： https://github.com/baidu/Paddle/pull/279 https://github.com/baidu/Paddle/issues/266

@reyoung @emailweixu