On Mon, Feb 23, 2009 at 05:22:39PM +0100, Peter Zijlstra wrote: > [...] > > > Not so. In both cases the regular stuff (NMI trace, OOPS, > > > function/graph/sched trace, etc) is not enough and you wish to > > > augment its output. > > > > Sorry, I don't see how that relates. If the general function tracing > > widgetry is insufficient for some subsystem/purpose, some sort of > > static instrumentation is needed. Whether that instrumentation is > > done by markers (with a thin glue to ftrace) or by tracepoints (with a > > thick glue to ftrace) doesn't change the need for "augmentation". > > I'm not arguing against static instrumentation per-se (although > expanding the coverage of dynamic/automatic instrumentation is much more > profitable IMHO). Much prior discussion (incl. at the kernel summit) indicates that we need both. > What I'm arguing is that trace_mark()s one distinguishing feature over > tracepoints is only suited for quick debug like work. I see where you're coming from, but one may also caricaturize the other alternative as requiring make-work glue code to pack & unpack all the same inforation. > Furthermore, trace_mark() exposes that crap like an ABI, now suppose > some distro goes and declares that stable for some daft reason, > imagine the poor sod having to fix something littered with > trace_mark(). The impression that this is somehow different with tracepoints is mistaken. Tracepoints are *exactly* as "ABI-like" as markers. > [...] presenting that information in big bloated blobs is beyond > that scope. Do you have some specific bloated blobs in mind? It's not as if the rendered text is necessarily much bigger than a struct containing all the same parameters. Consider all the fields rounded up to 4 or 8 bytes each. - FChE -- To unsubscribe from this list: send the line "unsubscribe linux-kbuild" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
