On Mon, 2007-03-05 at 12:59 -0500, Frank Ch. Eigler wrote: > Tom Zanussi <[EMAIL PROTECTED]> writes:
> > # stap -I tapsets countall.stp > > # btrace /dev/hda > > Is there some way for the systemtap script to perform the tracing > activation done by the btrace tool? AFAIK, there's no API in blktrace that would allow the runtime to easily toggle tracing on/off from the kernel side. It would probably take just a couple lines of code to add something that would do it, but that would also add a couple to tests to the logging path, which I doubt would be acceptable. So probably best to just have a shell script that starts the systemtap script and also starts blktrace. Personally I don't find it too onerous to start blktrace manually, but I'm guessing you might have other possibilities in mind for solving this problem. ;-) > > > [...] This script needs a couple extra changes to the normal commandline, so > > it doesn't choke on some default systemtap limits: > > # stap -I tapsets -DMAXMAPENTRIES=10000 -DMAXACTION=10000 iotop.stp > > [...] > > In what cases would your script come up against the MAXACTION limits? I probably just kept this command-line from previous tests where it did matter - I often use these defensively in order to avoid having a long-running script run to completion only to choke at the end when printing the results. Tom - To unsubscribe from this list: send the line "unsubscribe linux-btrace" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
