lkml.org 
[lkml]   [2009]   [Mar]   [21]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [PATCH] tracing: Fix TRACING_SUPPORT dependency

* Steven Rostedt <rostedt@goodmis.org> wrote:

>
> On Sat, 21 Mar 2009, Ingo Molnar wrote:
>
> >
> > * Anton Vorontsov <avorontsov@ru.mvista.com> wrote:
> >
> > > On Fri, Mar 20, 2009 at 08:57:43PM +0100, Ingo Molnar wrote:
> > > >
> > > > * Anton Vorontsov <avorontsov@ru.mvista.com> wrote:
> > > >
> > > > > On Fri, Mar 20, 2009 at 08:04:28PM +0100, Ingo Molnar wrote:
> > > > > >
> > > > > > * Anton Vorontsov <avorontsov@ru.mvista.com> wrote:
> > > > > >
> > > > > > > commit 40ada30f9621fbd831ac2437b9a2a399aad34b00 ("tracing: clean
> > > > > > > up menu"), despite the "clean up" in its purpose, introduced
> > > > > > > behavioural change for Kconfig symbols: we no longer able to
> > > > > > > select tracing support on PPC32 (because IRQFLAGS_SUPPORT isn't
> > > > > > > yet implemented).
> > > > > >
> > > > > > Could you please solve this by implementing proper
> > > > > > irqflag-tracing support? It's been available upstream for almost
> > > > > > three years. It's needed for lockdep support as well, etc.
> > > > >
> > > > > Breaking things via clean up patches is an interesting method of
> > > > > encouraging something to implement. ;-)
> > > > >
> > > > > Surely I'll look into implementing irqflags tracing, but
> > > > > considering that no one ever needed this for almost three years,
> > > > > [...]
> > > >
> > > > Weird, there's no lockdep support?
> > >
> > > *ashamed*: apparently no such support currently exist for PPC32. ;-)
> >
> > Hm, do all the tracers even compile on ppc32 with your patch?
> >
> > We had periodic build failures on weird, unmaintained architectures
> > that had no irqflags-tracing support and hence didnt know the
> > raw_irqs_save/restore primitives ...
> >
> > I'm not trying to make things more difficult for you (and we can
> > apply your patch if it builds fine and does not cause problems
> > elsewhere), but there were some real downsides to not having proper
> > irq APIs ...
>
> Note, the issue is not with the hooks into local_irq_save/restore,
> but with the entry.S code. That code is very sensitive where the
> irqs are enabled and disabled.

i know. What i'm talking about is that non-lockdep architectures
have the habit of not defining raw_local_irq_save() - which the
tracing core relies on.

Ingo


\
 
 \ /
  Last update: 2009-03-21 17:37    [from the cache]
©2003-2011 Jasper Spaans