Re: odd -CURRENT performance issue
From: John Baldwin (jhb_at_FreeBSD.org)
To: freebsd-current@FreeBSD.org Date: Tue, 8 Feb 2005 13:26:14 -0500
On Monday 07 February 2005 06:49 pm, Don Lewis wrote:
> time make all-depends-list
> ten times in a row in /usr/ports/x11/gnome2. The system was freshly
> booted, and other than a niced setiathome, the system was idle. I got
> the following results:
> 122.63 real 29.83 user 66.29 sys
> 117.86 real 29.58 user 66.55 sys
> 119.89 real 29.80 user 67.27 sys
> 121.68 real 30.31 user 67.55 sys
> 122.10 real 30.41 user 67.66 sys
> 120.90 real 29.67 user 68.24 sys
> 121.21 real 30.27 user 67.69 sys
> 219.85 real 30.35 user 148.12 sys
> 312.54 real 30.49 user 224.79 sys
> 312.83 real 30.23 user 225.83 sys
> The last three lines are rather strange ...
> Kernel and world are 6.0-CURRENT, built from February 3rd sources.
> WITNESS, INVARIANTS, DEBUG_VFS_LOCKS, and SMP enabled, and it is fairly
> close to GENERIC.
WITNESS has especially poor scalability issues and can get much worse as more
lock classes and relationships are added to its tree due to how it tries to
rebalance the tree every time it adds a new relationship (and each rebalance
is O(n) I think). If you turn off witness via sysctl debug.witness.watch=0,.
does the same weirdness persist?
-- John Baldwin <jhb@FreeBSD.org> <>< http://www.FreeBSD.org/~jhb/ "Power Users Use the Power to Serve" = http://www.FreeBSD.org _______________________________________________ email@example.com mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-current To unsubscribe, send any mail to "firstname.lastname@example.org"