trunk/4e561321b85d0c6357b46a379db9d92be0ba441a: [MPS] Make event synchronization and timing reliable (#196395)

发生了什么

Human reviewer note: These issues were discovered while enabling Autotuning in Helion Metal backend using MPSEvents to record kernel durations, instead of relying on host timestamps. Problem MPS events could fail in two user-visible ways. First, synchronizing a timing event and then measuring it could hang: start . record () out = x + y end . record () end . synchronize () start . elapsed_time ( end ) # could wait f…

摘要按规则整理自下方来源原文

来源