For those people experiencing a performance degradation since the DTrace import, please update your copy of src/sys/cddl/compat/opensolaris/kern/opensolaris_kmem.c by either cvsup of direct edit to remove "#define KMEM_DEBUG". You only need to rebuild the opensolaris kernel module after this change. The code is shared between ZFS and DTrace via the opensolaris kernel module. This is also the reason why you found it necessary to add KDB, DDB and STACK to your kernel. After removing KMEM_DEBUG, you won't need those. Please confirm that this solves the problem you have been seeing. -- John Birrell
John Birrell wrote:> For those people experiencing a performance degradation since the DTrace import, > please update your copy of src/sys/cddl/compat/opensolaris/kern/opensolaris_kmem.c > by either cvsup of direct edit to remove "#define KMEM_DEBUG". > > You only need to rebuild the opensolaris kernel module after this change. The code > is shared between ZFS and DTrace via the opensolaris kernel module. > > This is also the reason why you found it necessary to add KDB, DDB and STACK to > your kernel. After removing KMEM_DEBUG, you won't need those. > > Please confirm that this solves the problem you have been seeing.Great, now everything is back to normal Thanks Henri> > -- > John Birrell > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org"
On Mon, 1 Sep 2008, John Birrell wrote:> For those people experiencing a performance degradation since the DTrace > import, please update your copy of > src/sys/cddl/compat/opensolaris/kern/opensolaris_kmem.c by either cvsup > of direct edit to remove "#define KMEM_DEBUG". > > You only need to rebuild the opensolaris kernel module after this > change. The code is shared between ZFS and DTrace via the opensolaris > kernel module. > > This is also the reason why you found it necessary to add KDB, DDB and > STACK to your kernel. After removing KMEM_DEBUG, you won't need those. > > Please confirm that this solves the problem you have been seeing.8 or so hours later and everything is good here. One other suggestion, the "opensolaris" module that is now required for zfs is not mentioned anywhere in UPDATING. Users of "MODULES_OVERRIDE" will likely find themselves with a system that will not boot without manual intervention, sometimes even requiring a live cd. A headsup or warning would probably be appreciated by other zfs'ers.
John Birrell wrote:> For those people experiencing a performance degradation since the DTrace import, > please update your copy of src/sys/cddl/compat/opensolaris/kern/opensolaris_kmem.c > by either cvsup of direct edit to remove "#define KMEM_DEBUG". > > You only need to rebuild the opensolaris kernel module after this change. The code > is shared between ZFS and DTrace via the opensolaris kernel module. > > This is also the reason why you found it necessary to add KDB, DDB and STACK to > your kernel. After removing KMEM_DEBUG, you won't need those. > > Please confirm that this solves the problem you have been seeing.Yes! Last night doing a csup would peg the Sys CPU usage at 100%. After rebuilding the opensolaris kernel module everything is back to normal. There's a csup running as I type this and the system is upwards of 90%Idle. Thanks, Yarema