Hi - oleg wrote: > [...] >> I'm personally very dubious that there are any merits to utrace that >> outweigh the very clear disadvantages: just another layer that adds a new >> level of abstraction to the only interface that people actually _use_, >> namely ptrace. > > Of course they can't use other interfaces, we don't have them. And > without the new abstraction layer we will never have, I think. This is one of the reasons we built, up on request of lkml people, the utrace-gdbstub prototype (http://lkml.org/lkml/2009/11/30/173). It presents a standard userspace debugging interface -- actually, more standard than ptrace! It has the potential to be more powerful feature-wise and perhaps even perform faster than ptrace. And yet that RFC didn't receive any on-topic review, only wishes for unspecified blue-sky integration with kernel debugging. So then there's uprobes, which is another potential utrace "killer app", if it weren't so tainted by some peoples' disdain for its current user, when other users are already being seriously discussed. So a working prototype, which demonstrates both the utility of utrace itself and the end-user value of user-space probing, is disregarded. And there are several smaller utrace clients in the works, each of them merge candidates in the future. Yes, most of them may be rewritten with special-purpose hook after hook as people reinvent the utrace wheel piece by piece, but how long will that take? How is the opportunity cost of missing features valued? Finally, I don't know how to address the logic of "if a feature requires utrace, that's a bad argument for utrace" and at the same time "you need to show a killer app for utrace". What could possibly satisfy both of those constraints? Please advise. - FChE -- To unsubscribe from this list: send the line "unsubscribe linux-next" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
