Improvements in HAMMER parallel I/O performance
With the latest master people should be seeing some serious improvement
in HAMMER's parallel I/O performance. e.g. simultanious reads and
writes, benchmarks, and so forth. The improvements will be more
pronounced if you are running SCSI, SILI, or the AHCI driver, but
NATA will see a good chunk of the improvements too.
These improvements are not in random I/O... e.g. find . or ls -lR on an
uncached directory tree. They are specifically for parallel I/O loads,
aka blogbench and friends.
I did some major work controlling buffer cache locking as it relates
to HAMMER, to reduce lock contention, and some major work on
bioqdisksort() to add write bleedover and write bursting to the
read priority scheme.
-Matt
Matthew Dillon
<dillon@backplane.com>