perf_counter: Remove ACPI quirk

We had a disable/enable around acpi_idle_do_entry() due to an erratum
in an early prototype CPU i had access to. That erratum has been fixed
in the BIOS so remove the quirk.

The quirk also kept us from profiling interrupts that hit the ACPI idle
instruction - so this is an improvement as well, beyond a cleanup and
a micro-optimization.

[ Impact: improve profiling scope, cleanup, micro-optimization ]

Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Corey Ashford <cjashfor@linux.vnet.ibm.com>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index 9645758..f7ca8c5 100644 (file)
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -765,7 +765,6 @@ static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
 {
        /* Don't trace irqs off for idle */
        stop_critical_timings();
-       perf_disable();
        if (cx->entry_method == ACPI_CSTATE_FFH) {
                /* Call into architectural FFH based C-state */
                acpi_processor_ffh_cstate_enter(cx);
@@ -780,7 +779,6 @@ static inline void acpi_idle_do_entry(struct acpi_processor_cx *cx)
                   gets asserted in time to freeze execution properly. */
                unused = inl(acpi_gbl_FADT.xpm_timer_block.address);
        }
-       perf_enable();
        start_critical_timings();
 }