nmi_backtrace: generate one-line reports for idle cpus

When doing an nmi backtrace of many cores, most of which are idle, the
output is a little overwhelming and very uninformative.  Suppress
messages for cpus that are idling when they are interrupted and just
emit one line, "NMI backtrace for N skipped: idling at pc 0xNNN".

We do this by grouping all the cpuidle code together into a new
.cpuidle.text section, and then checking the address of the interrupted
PC to see if it lies within that section.

This commit suitably tags x86 and tile idle routines, and only adds in
the minimal framework for other architectures.

Link: http://lkml.kernel.org/r/[email protected]
Signed-off-by: Chris Metcalf <[email protected]>
Acked-by: Peter Zijlstra (Intel) <[email protected]>
Tested-by: Peter Zijlstra (Intel) <[email protected]>
Tested-by: Daniel Thompson <[email protected]> [arm]
Tested-by: Petr Mladek <[email protected]>
Cc: Aaron Tomlin <[email protected]>
Cc: Peter Zijlstra (Intel) <[email protected]>
Cc: "Rafael J. Wysocki" <[email protected]>
Cc: Russell King <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This commit is contained in:
Chris Metcalf 2016-10-07 17:02:55 -07:00 • committed by Linus Torvalds
commit 6727ad9e20
49 changed files with 93 additions and 22 deletions

View file

@ -31,6 +31,7 @@
#include <linux/sched.h> /* need_resched() */
#include <linux/tick.h>
#include <linux/cpuidle.h>
#include <linux/cpu.h>
#include <acpi/processor.h>
/*
@ -115,7 +116,7 @@ static const struct dmi_system_id processor_power_dmi_table[] = {
* Callers should disable interrupts before the call and enable
* interrupts after return.
*/
static void acpi_safe_halt(void)
static void __cpuidle acpi_safe_halt(void)
{
if (!tif_need_resched()) {
safe_halt();
@ -645,7 +646,7 @@ static int acpi_idle_bm_check(void)
*
* Caller disables interrupt before call and enables interrupt after return.
*/
static void acpi_idle_do_entry(struct acpi_processor_cx *cx)
static void __cpuidle acpi_idle_do_entry(struct acpi_processor_cx *cx)
{
if (cx->entry_method == ACPI_CSTATE_FFH) {
/* Call into architectural FFH based C-state */