lkml.org 
[lkml]   [2007]   [Jan]   [9]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Date
From
SubjectRe: [PATCH] add i386 idle notifier (take 3)
Hello,

On Fri, Jan 05, 2007 at 02:36:53PM +0100, Adrian Bunk wrote:
> > > > > Where does the perfmon code use the EXPORT_SYMBOL's?
> > > >
> > > > The perfmon patch includes several kernel modules which make use of
> > > > the exported entry points. The following symbols are exported:
> > > >
> > > > pfm_pmu_register/pfm_pmu_unregister:
> > > > * PMU description module registration.
> > > > * Used to describe PMU model.
> > > > * Used by perfmon_p4.c, perfmon_core.c, perfmon_mckinley.c, and others
> > > >
> > > > pfm_fmt_register/pfm_fmt_unregister:
> > > > * Sampling format module registration
> > > > * Used by perfmon_dfl_smpl.c, perfmon_pebs_smpl.c
> > > >
> > > > pfm_interrupt_handler:
> > > > * PMU interrupt handler
> > > > * Used by MIPS-specific perfmon code
> > > >
> > > > pfm_pmu_conf/pfm_controls:
> > > > * global state/control variable
> > > >
> > > > All exported symbols are currently used. Why are you saying this adds bloat?
> > >
> > > Which module uses idle_notifier_register/idle_notifier_unregister?
> > >
> > None.
> >
> > I have no issue with removing the EXPORT_SYMBOL on i386 and x86_64 if you
> > think that would help.
>

As a follow-up to this discussion, here is a patch that remove unused
EXPORT_SYMBOL by the i386 idle notifier. It also make it more explicit
that the enter_idle() store must be atomic.

changelog:
- do not export i386 idle notification registration entry points
because there is currently no user for this
- make it more explicit that the store to idle_state must be atomic

signed-off-by: stephane eranian <eranian@hpl.hp.com>

--- linux-2.6.20-rc3-mm1.orig/arch/i386/kernel/process.c 2007-01-08 01:58:08.000000000 -0800
+++ linux-2.6.20-rc3-mm1/arch/i386/kernel/process.c 2007-01-08 02:01:59.000000000 -0800
@@ -87,19 +87,18 @@ void idle_notifier_register(struct notif
{
atomic_notifier_chain_register(&idle_notifier, n);
}
-EXPORT_SYMBOL_GPL(idle_notifier_register);

void idle_notifier_unregister(struct notifier_block *n)
{
atomic_notifier_chain_unregister(&idle_notifier, n);
}
-EXPORT_SYMBOL(idle_notifier_unregister);

static DEFINE_PER_CPU(volatile unsigned long, idle_state);

void enter_idle(void)
{
- __get_cpu_var(idle_state) = 1;
+ /* needs to be atomic w.r.t. interrupts, not against other CPUs */
+ __set_bit(0, &__get_cpu_var(idle_state));
atomic_notifier_call_chain(&idle_notifier, IDLE_START, NULL);
}

-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
\
 
 \ /
  Last update: 2007-01-09 13:07    [W:0.105 / U:0.208 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site