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

    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.

    -- Steve



    \
     
     \ /
      Last update: 2009-03-21 17:35    [W:0.021 / U:183.168 seconds]
    ©2003-2016 Jasper Spaans. hosted at Digital OceanAdvertise on this site