On Wed, Jun 26, 2019 at 05:15:45PM -0700, Dan Williams wrote: > Ever since the conversion of DAX to the Xarray a RocksDB benchmark has > been encountering intermittent lockups. The backtraces always include > the filesystem-DAX PMD path, multi-order entries have been a source of > bugs in the past, and disabling the PMD path allows a test that fails in > minutes to run for an hour. On May 4th, I asked you: Since this is provoked by a fatal signal, it must have something to do with a killable or interruptible sleep. There's only one of those in the DAX code; fatal_signal_pending() in dax_iomap_actor(). Does rocksdb do I/O with write() or through a writable mmap()? I'd like to know before I chase too far down this fault tree analysis.