On Sun, Apr 20, 2014 at 11:57:46PM -0700, Christoph Hellwig wrote: > On Thu, Apr 17, 2014 at 10:39:56AM +1000, Dave Chinner wrote: > > so, basically a script that does: > > > > #!/bin/bash > > > > TRACEDIR=/sys/kernel/debug/tracing > > > > grep -i 't xfs_' /proc/kallsyms | awk '{print $3}' ; while read F; do > > echo "r:ret_$F $F \$retval" >> $TRACEDIR/kprobe_events > > done > > > > for E in $TRACEDIR/events/kprobes/ret_xfs_*/enable; do > > echo 1 > $E > > done; > > > > echo 'arg1 > 0xffffffffffffff00' > $TRACEDIR/events/kprobes/filter > > > > for T in $TRACEDIR/events/kprobes/ret_xfs_*/trigger; do > > echo 'traceoff if arg1 > 0xffffffffffffff00' > $T > > done > > This looks incredibly useful! Can we throw this into Documentation/ as > a helper script (and make the xfs a command line parameter so it's > genericly useful)? So does that mean you have no more objections to removing XFS_ERROR()? The thing is, that's a quick hack that spews errors all over the place, especially if you run it twice. It needs a counterpart to turn off the tracing, clean up the triggers, etc.... FWIW, what I'd really like is a trace event trigger that triggers a BUG(), so that we can use it to drop into kernel debuggers or get kdump to generate a core that can be analysed offline... > One think that would be nice is to specify a module instead of relying > on a clean namespace, but to replace the XFS functionality the one above > is more than enough. My current hack is invoked like this: $ grep -i 't xfs_' /proc/kallsyms | retval_filter.sh Makes it completely independent of how you supply the symbols to the function. Hence my coments about how it'd be really cool to have this built into in trace-cmd, because the mechanism is independent of how you specify the function list... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs