Has anyone re-run those IO benchmarks? Something smells fishy there.. (with the benchmarking.)
adrian 2011/7/6 O. Hartmann <ohart...@zedat.fu-berlin.de>: > On 07/06/11 12:37, arrowdodger wrote: >> >> 2011/7/6 O. Hartmann<ohart...@zedat.fu-berlin.de> >> >>> When performing an update on the ports tree via "portsnap fetch update" >>> or >>> when checking out (or) large Subversion repositories or when copying >>> large >>> data files (~ 50 to 250 GB in size, results from numerical modelings) or >>> when compiling world, FreeBD 9.0 and FreeBSD 8.2-STABLE tend to "freeze" >>> for >>> several seconds or drop overall performance dramatically for seconds. On >>> boxes with only console- or terminal access (no GUI) a running 'vi' gets >>> stuck for seconds while one of the processes producing heavy I/O is >>> running, >>> or the output of a 'cat' of a large file stops for several seconds. >>> >>> Using X11, this phenomenon gets even worse and the 'freezing' tends to >>> persist sometimes for more than 10 or 15 seconds. >>> >> >> I've also had (and still having) this problem on FreeBSD 7.2-RELEASE and >> 8-STABLE with both UFS and ZFS. Though, i've been running FreeBSD not on >> powerful servers, but on laptops (2-core CPU's, 2 GB of RAM). But still, >> KDE4 on Linux performs much better during high disk IO. > > I read about issues with the old codebase of X11 in FreeBSD's ports used, > which could be the cause of some performance problems, but I wouldn't expect > those I/O-triggered blockings on boxes without any GUI. > > I saw Linux very often performing tremendously better when used as a > workstation or desktop, but this is often gained on the costs of other > subsystems. I followed a very hard-to-understand discussion about grouping > threads related to ttys which seems to get higher priorized in Linux to make > the GUI more fluent, but this is definitely on cost of other subsystems, > which in consequence gets less priorized. > But even without GUI, Linux seems to perform I/O much better on > multicore-/multiprocessor boxes than FreeBSD *.X and 9.X). > > Today I looked at some benchmarks performed by Phoronix/openbenchmark.org > (http://www.phoronix.com/scan.php?page=article&item=freebsd8_ubuntu910&num=9) > and it seems that threaded I/O is an issue in FreeBSD (compared to Linux). I > have no glue how to "tune" those bottlenecks away in FBSD. > > I use SCHED_ULE on all machines, since it is supposed to be performing > better on multicore boxes, but there are lots of suggestions switching back > to the old SCHED_4BSD scheduler. > > Oliver > > _______________________________________________ > firstname.lastname@example.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-current > To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org" > _______________________________________________ email@example.com mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "freebsd-current-unsubscr...@freebsd.org"