Chinese President Xi Jinping used his first speech since taking over to indirectly call out North Korea for being so prickly lately. He never mentioned the country by name, but it's pretty clear who he was referring to.
Xi's remarks came in the middle of a speech to foreign dignitaries that focused primarily on China's economic strength. But Xi also chastised Pyongang for attempting to destabilize the Korean peninsula. Without specifying a country, Xi said no one "should be allowed to throw a region and even the whole world into chaos for selfish gain." Stability in Asia "faces new challenges, as hot spot issues keep emerging and both traditional and non-traditional security threats exist," he said. Given everything that's happened recently, it seems pretty clear which country Xi was speaking to.
If Xi's remarks aren't a clear indication of how tired China's become with North Korea's posturing, statements made by foreign minister Wang Yi when speaking with U.N. Secretary-General Ban Ki-moon should eliminate any doubt. "We oppose provocative words and actions from any party in the region and do not allow trouble making on China's doorstep," Wang said.