> Would the logic behind ZFS take full advantage of a heavily multicored > system, such as on the Sun Niagara platform? Would it utilize of the > 32 concurrent threads for generating its checksums? Has anyone > compared ZFS on a Sun Tx000, to that of a 2-4 thread x64 machine?
Pete and I are working on resolving ZFS scalability issues with Niagara and StarCat right now. I'm not sure if any official numbers about ZFS performance on Niagara have been published. As far as concurrent threads generating checksums goes, the system doesn't work quite the way you have postulated. The checksum is generated in the ZIO_STAGE_CHECKSUM_GENERATE pipeline state for writes, and verified in the ZIO_STAGE_CHECKSUM_VERIFY pipeline stage for reads. Whichever thread happens to advance the pipline to the checksum generate stage is the thread that will actually perform the work. ZFS does not break the work of the checksum into chunks and have multiple CPUs perform the computation. However, it is possible to have concurrent writes simultaneously in the checksum_generate stage. More details about this can be found in zfs/zio.c and zfs/sys/zio_impl.h -j _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
