I don't. What I meant was that a single thread (geom) is limiting the performance of the system overall. I'm certain, based on top, gstat, and zpool iostat, that geom is the limiting factor on this system. -Alan
On Fri, Jul 3, 2020 at 2:18 PM Paweł Jakub Dawidek <[email protected]> wrote: > Hi Alan, > > why do you think it will hurt single-threaded performance? > > -- > Paweł Jakub Dawidek > > > > > On Jul 3, 2020, at 12:30, Alan Somers <[email protected]> wrote: > > > > I'm using geli, gmultipath, and ZFS on a large system, with hundreds of > > drives. What I'm seeing is that under at least some workloads, the > overall > > performance is limited by the single geom kernel process. procstat and > > kgdb aren't much help in telling exactly why this process is using so > much > > CPU, but it certainly must be related to the fact that over 15,000 IOPs > are > > going through that thread. What can I do to improve this situation? > Would > > it make sense to enable direct dispatch for geli? That would hurt > > single-threaded performance, but probably improve performance for highly > > multithreaded workloads like mine. > > > > Example top output: > > PID USERNAME PRI NICE SIZE RES STATE C TIME WCPU COMMAND > > 13 root -8 - 0B 96K CPU46 46 82.7H 70.54% > > geom{g_down} > > 13 root -8 - 0B 96K - 9 35.5H 25.32% > > geom{g_up} > > > > -Alan > > _______________________________________________ > > [email protected] mailing list > > https://lists.freebsd.org/mailman/listinfo/freebsd-geom > > To unsubscribe, send any mail to "[email protected]" > > _______________________________________________ [email protected] mailing list https://lists.freebsd.org/mailman/listinfo/freebsd-geom To unsubscribe, send any mail to "[email protected]"
