On Sun, Jun 24, 2012 at 08:50:41PM +0200, Wojciech Puchar wrote: > >> > >> > >>There is nothing in cron that is done at sunday. > >> > >>i don't run "periodic" stuff in /etc/crontab > >> > > > >Compile the kernel with the following: > > > >makeoptions DEBUG="-O0 -g" > > > >options KDB # Enable kernel debugger support. > >options DDB # Support DDB. > >options GDB # Support remote GDB. > >options DEADLKRES # Enable the deadlock resolver > >options INVARIANTS # Enable calls of extra sanity > >checking > >options INVARIANT_SUPPORT # Extra sanity checks of internal > >structures, required by INVARIANTS > >options WITNESS # Enable checks to detect deadlocks > >and cycles > >options WITNESS_SKIPSPIN # Don't run witness on spinlocks for > >speed > >options DIAGNOSTIC > > > >After kernel panic ddb prompt will be waiting for you. Type in: > >dump <enter> > >reset <enter> > > > >Make sure you have swap that can handle crashdumps. > > already did this part and debug part, but not DDB. As you see - hang > not crashdump > > how much would it slow down whole thing? > > If less than 2 times it can be - CPU are rerely half loaded
Are you asking about overhead of DDB or all debug options? I don't think that DDB support can be accounted for slowdown. As for the rest, it's hard to say. I guess it depends on your workload, also I never performed any benchmarks to compare this and I'm unaware of any. In other words, you have to test it yourself. -- Mateusz Guzik <mjguzik gmail.com> _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
