On Sat, 21 Mar 2009 10:12:35 +0100 Ingo Molnar <mi...@elte.hu> wrote:
> > * Andrew Morton <a...@linux-foundation.org> wrote: > > > On Sat, 21 Mar 2009 08:43:01 +0100 Ingo Molnar <mi...@elte.hu> wrote: > > > > > > > > * Roland McGrath <rol...@redhat.com> wrote: > > > > > > > From: Frank Ch. Eigler <f...@redhat.com> > > > > > > > > This is v2 of the prototype utrace-ftrace interface. This code is > > > > based on Roland McGrath's utrace API, which provides programmatic > > > > hooks to the in-tree tracehook layer. This new patch interfaces > > > > many of those events to ftrace, as configured by a small number of > > > > debugfs controls. Here's the > > > > /debugfs/tracing/process_trace_README: > > > > > > Please submit changes/enhancements to kernel/trace/* to the tracing > > > tree maintainers (Steve and me) for review, testing and integration. > > > > > > Please also post patches against the latest tracing tree: > > > > > > http://people.redhat.com/mingo/tip.git/README > > > > uhm, this patch depends on the (large) utrace patch, which is not > > kernel/trace material. > > The thing is, utrace crashes in Fedora have dominated kerneloops.org > for many months, so i'm not sure what to make of the idea of posting > a 4000+ lines of core kernel code patchset on the last day of the > development cycle, a posting that has carefully avoided the Cc:-ing > of affected maintainers ;-) > > Utrace is very much tracing material - without the ftrace plugin the > whole utrace machinery is just something that provides a _ton_ of > hooks to something entirely external: SystemTap mainly. Roland's changelogs don't mention systemtap at all afacit. That was, umm, major information lossage. > kernel/utrace.c should probably be introduced as > kernel/trace/utrace.c not kernel/utrace.c. It also overlaps pending > work in the tracing tree and cooperation would be nice and desired. > > The ftrace/utrace plugin is the only real connection utrace has to > the mainline kernel, so proper review by the tracing folks and > cooperation with the tracing folks is very much needed for the whole > thing. Actually it seems that the whole utrace-ftrace thing is a big distraction and could/should just be omitted. This is a systemtap feature and should be viewed as such. This is all a bit weird.
