On Fri, Dec 23, 2011 at 11:46:29AM -0500, Mathieu Desnoyers wrote: > - It's doing so without even needing it: Perf is using an ABI versioning > scheme designed for filesystems, when it is not in fact driven by the > same constraints. Well, there are *some* constraints. I've been assured that despite the fact that the perf client is in the kernel sources (something which I still think is a bad idea, since it's leading to other bad choices like kvm-tool wanting to be bundled with kernel sources), that it is *not* a license to jerk the format around wildly --- that people will have installed userspace binaries that shouldn't randomly break they boot a new kernel. So I'm *glad* that Perf is using an ABI versioning scheme that accepts the same restraints as file systems. It means we don't randomly break userspace tools. So Mathieu, if you think it is the current standards of backwards compatibility are too rigid, what level of tool breakage do you think is acceptable? It's not just about the backwards compatibility of the trace files, it's also about compatibility of userspace utilities. For example, systemtap, where you had to recompile from source at each kernel revision, and pray it would still build goes too far in the other direction, wouldn't you agree? What is the correct level of kernel developer annoyance you think is appropriate to inflict on ourselves? Regards, - Ted _______________________________________________ devel mailing list devel@xxxxxxxxxxxxxxxxxxxxxx http://driverdev.linuxdriverproject.org/mailman/listinfo/devel
