Messages in this thread Patch in this message | | | Date | Tue, 9 Jan 2007 02:49:07 -0800 | From | Stephane Eranian <> | Subject | Re: [PATCH] add i386 idle notifier (take 3) |
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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/
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