On Mon, Jul 11, 2011 at 12:25 AM, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > On Sun, 2011-07-10 at 14:53 +0300, Pekka Enberg wrote: >> On Sun, Jul 10, 2011 at 1:58 PM, Rafael J. Wysocki <rjw@xxxxxxx> wrote: >> > This message has been generated automatically as a part of a report >> > of regressions introduced between 2.6.38 and 2.6.39. >> > >> > The following bug entry is on the current list of known regressions >> > introduced between 2.6.38 and 2.6.39. Please verify if it still should >> > be listed and let the tracking team know (either way). >> > >> > Bug-Entry : http://bugzilla.kernel.org/show_bug.cgi?id=38132 >> > Subject : [Warning] 2.6.39.x latencytop >> > Submitter : Andrew Watts <akwatts@xxxxxxxxx> >> > Date : 2011-06-14 17:07 (27 days old) >> > Message-ID : <80098.5633.qm@xxxxxxxxxxxxxxxxxxxxxxxxxxxx> >> > References : http://marc.info/?l=linux-kernel&m=130807128506490&w=2 >> >> This is a WARN_ON added in commit 6752ab4a ("tracing: Deprecate >> tracing_enabled for tracing_on") that lets the user know about >> deprecated ABI. It's somewhat unfortunate that there's no mention in >> the changelog if everyone agreed on the deprecation or not... >> >> That said, assuming the deprecation is OK (hi Steven, Frederic, Ingo!) >> I think this issue can be closed. > > I deprecated it because I said I would for the last year ;) > > The tracing_enabled never did what it was suppose to do. It was suppose > to be a "quick" way to disable tracing without fully disabling it. It > was suppose to try to turn things off to a low overhead but not fully > off without any overhead. The problem is that it never really worked > well. The only tracer that does anything different with it as suppose to > tracing_on, is the irqsoff tracers. They stop looking at max latencies > when you echo 0 into tracing_enabled. But that's it. Everything else, > it's just the same as echoing 0 into tracing_on. I think the irqsoff > tracers now even look at tracing_on if it should trace a max latency or > not, so tracing_enabled doesn't even help with that. > > We can keep it around but I don't see any good reason for it besides not > having latency top give a warning. AFAICT, if you go ahead with the deprecation and actually remove the file, you'll break latencytop fsync tracing. On Mon, Jul 11, 2011 at 12:25 AM, Steven Rostedt <rostedt@xxxxxxxxxxx> wrote: > Question: Why is latency top even touching this file? Looking at the sources, it seems to use it to enable fsync tracing. I don't know the details so lets CC Arjan. -- To unsubscribe from this list: send the line "unsubscribe kernel-testers" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
