[PATCH] ACPI: processor: idle: Add __cpuidle to acpi_idle_lpi_enter

[PATCH] ACPI: processor: idle: Add __cpuidle to acpi_idle_lpi_enter

[lirongqing]

From: Li RongQing <lirongqing@baidu.com>

When function tracing is enabled, entering an LPI idle state
triggers:

  RCU not on for: acpi_idle_lpi_enter+0x4/0xd8
  WARNING: CPU: 8 PID: 0 at include/linux/trace_recursion.h:162
           function_trace_call+0x1e8/0x228

acpi_idle_lpi_enter is called from the cpuidle path where RCU
may already be disabled. ftrace's function_trace_call checks
that RCU is watching before recording, and warns otherwise.

Mark the function with __cpuidle, which includes notrace, to
suppress ftrace instrumentation in this path. Other cpuidle
enter functions already carry this annotation.

Fixes: a36a7fecfe60 ("ACPI / processor_idle: Add support for Low Power Idle(LPI) states")
Signed-off-by: Li RongQing <lirongqing@baidu.com>
---
 drivers/acpi/processor_idle.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/acpi/processor_idle.c b/drivers/acpi/processor_idle.c
index ee5facc..0ca404b 100644
--- a/drivers/acpi/processor_idle.c
+++ b/drivers/acpi/processor_idle.c
@@ -1156,7 +1156,7 @@ int __weak acpi_processor_ffh_lpi_enter(struct acpi_lpi_state *lpi)
  *
  * Return: 0 for success or negative value for error
  */
-static int acpi_idle_lpi_enter(struct cpuidle_device *dev,
+static int __cpuidle acpi_idle_lpi_enter(struct cpuidle_device *dev,
 			       struct cpuidle_driver *drv, int index)
 {
 	struct acpi_processor *pr;
-- 
2.9.4

Re: [PATCH] ACPI: processor: idle: Add __cpuidle to acpi_idle_lpi_enter

[kernel test robot]

Hi lirongqing,

kernel test robot noticed the following build warnings:

[auto build test WARNING on rafael-pm/linux-next]
[also build test WARNING on rafael-pm/bleeding-edge linus/master v7.1 next-20260612]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/lirongqing/ACPI-processor-idle-Add-__cpuidle-to-acpi_idle_lpi_enter/20260615-150110
base:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
patch link:    https://lore.kernel.org/r/20260615065401.4611-1-lirongqing%40baidu.com
patch subject: [PATCH] ACPI: processor: idle: Add __cpuidle to acpi_idle_lpi_enter
config: x86_64-defconfig (https://download.01.org/0day-ci/archive/20260615/202606151932.LNUR0wXJ-lkp@intel.com/config)
compiler: gcc-14 (Debian 14.2.0-19) 14.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260615/202606151932.LNUR0wXJ-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202606151932.LNUR0wXJ-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> vmlinux.o: warning: objtool: acpi_idle_lpi_enter+0x28: call to acpi_processor_ffh_lpi_enter() leaves .noinstr.text section

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH] ACPI: processor: idle: Add __cpuidle to acpi_idle_lpi_enter

[kernel test robot]

Hi lirongqing,

kernel test robot noticed the following build errors:

[auto build test ERROR on rafael-pm/linux-next]
[also build test ERROR on rafael-pm/bleeding-edge linus/master v7.1]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/lirongqing/ACPI-processor-idle-Add-__cpuidle-to-acpi_idle_lpi_enter/20260615-150110
base:   https://git.kernel.org/pub/scm/linux/kernel/git/rafael/linux-pm.git linux-next
patch link:    https://lore.kernel.org/r/20260615065401.4611-1-lirongqing%40baidu.com
patch subject: [PATCH] ACPI: processor: idle: Add __cpuidle to acpi_idle_lpi_enter
config: x86_64-randconfig-072-20260615 (https://download.01.org/0day-ci/archive/20260616/202606160341.VjG95TFw-lkp@intel.com/config)
compiler: clang version 22.1.3 (https://github.com/llvm/llvm-project e9846648fd6183ee6d8cbdb4502213fcf902a211)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260616/202606160341.VjG95TFw-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202606160341.VjG95TFw-lkp@intel.com/

All errors (new ones prefixed by >>):

>> vmlinux.o: error: objtool: acpi_idle_lpi_enter+0x44: call to acpi_processor_ffh_lpi_enter() leaves .noinstr.text section

--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki