[PATCH 26/36] cpuidle,sched: Remove annotations from TIF_{POLLING_NRFLAG,NEED_RESCHED}

From: Peter Zijlstra
Date: Wed Jun 08 2022 - 10:47:12 EST


vmlinux.o: warning: objtool: mwait_idle+0x5: call to current_set_polling_and_test() leaves .noinstr.text section
vmlinux.o: warning: objtool: acpi_processor_ffh_cstate_enter+0xc5: call to current_set_polling_and_test() leaves .noinstr.text section
vmlinux.o: warning: objtool: cpu_idle_poll.isra.0+0x73: call to test_ti_thread_flag() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle+0xbc: call to current_set_polling_and_test() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_irq+0xea: call to current_set_polling_and_test() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_s2idle+0xb4: call to current_set_polling_and_test() leaves .noinstr.text section

vmlinux.o: warning: objtool: intel_idle+0xa6: call to current_clr_polling() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_irq+0xbf: call to current_clr_polling() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_s2idle+0xa1: call to current_clr_polling() leaves .noinstr.text section

vmlinux.o: warning: objtool: mwait_idle+0xe: call to __current_set_polling() leaves .noinstr.text section
vmlinux.o: warning: objtool: acpi_processor_ffh_cstate_enter+0xc5: call to __current_set_polling() leaves .noinstr.text section
vmlinux.o: warning: objtool: cpu_idle_poll.isra.0+0x73: call to test_ti_thread_flag() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle+0xbc: call to __current_set_polling() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_irq+0xea: call to __current_set_polling() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_s2idle+0xb4: call to __current_set_polling() leaves .noinstr.text section

vmlinux.o: warning: objtool: cpu_idle_poll.isra.0+0x73: call to test_ti_thread_flag() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_s2idle+0x73: call to test_ti_thread_flag.constprop.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle_irq+0x91: call to test_ti_thread_flag.constprop.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: intel_idle+0x78: call to test_ti_thread_flag.constprop.0() leaves .noinstr.text section
vmlinux.o: warning: objtool: acpi_safe_halt+0xf: call to test_ti_thread_flag.constprop.0() leaves .noinstr.text section

Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
---
include/linux/sched/idle.h | 40 ++++++++++++++++++++++++++++++----------
include/linux/thread_info.h | 18 +++++++++++++++++-
2 files changed, 47 insertions(+), 11 deletions(-)

--- a/include/linux/sched/idle.h
+++ b/include/linux/sched/idle.h
@@ -23,12 +23,37 @@ static inline void wake_up_if_idle(int c
*/
#ifdef TIF_POLLING_NRFLAG

-static inline void __current_set_polling(void)
+#ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_ATOMIC_H
+
+static __always_inline void __current_set_polling(void)
{
- set_thread_flag(TIF_POLLING_NRFLAG);
+ arch_set_bit(TIF_POLLING_NRFLAG,
+ (unsigned long *)(&current_thread_info()->flags));
}

-static inline bool __must_check current_set_polling_and_test(void)
+static __always_inline void __current_clr_polling(void)
+{
+ arch_clear_bit(TIF_POLLING_NRFLAG,
+ (unsigned long *)(&current_thread_info()->flags));
+}
+
+#else
+
+static __always_inline void __current_set_polling(void)
+{
+ set_bit(TIF_POLLING_NRFLAG,
+ (unsigned long *)(&current_thread_info()->flags));
+}
+
+static __always_inline void __current_clr_polling(void)
+{
+ clear_bit(TIF_POLLING_NRFLAG,
+ (unsigned long *)(&current_thread_info()->flags));
+}
+
+#endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_ATOMIC_H */
+
+static __always_inline bool __must_check current_set_polling_and_test(void)
{
__current_set_polling();

@@ -41,12 +66,7 @@ static inline bool __must_check current_
return unlikely(tif_need_resched());
}

-static inline void __current_clr_polling(void)
-{
- clear_thread_flag(TIF_POLLING_NRFLAG);
-}
-
-static inline bool __must_check current_clr_polling_and_test(void)
+static __always_inline bool __must_check current_clr_polling_and_test(void)
{
__current_clr_polling();

@@ -73,7 +93,7 @@ static inline bool __must_check current_
}
#endif

-static inline void current_clr_polling(void)
+static __always_inline void current_clr_polling(void)
{
__current_clr_polling();

--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -177,7 +177,23 @@ static __always_inline unsigned long rea
clear_ti_thread_flag(task_thread_info(t), TIF_##fl)
#endif /* !CONFIG_GENERIC_ENTRY */

-#define tif_need_resched() test_thread_flag(TIF_NEED_RESCHED)
+#ifdef _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H
+
+static __always_inline bool tif_need_resched(void)
+{
+ return arch_test_bit(TIF_NEED_RESCHED,
+ (unsigned long *)(&current_thread_info()->flags));
+}
+
+#else
+
+static __always_inline bool tif_need_resched(void)
+{
+ return test_bit(TIF_NEED_RESCHED,
+ (unsigned long *)(&current_thread_info()->flags));
+}
+
+#endif /* _ASM_GENERIC_BITOPS_INSTRUMENTED_NON_ATOMIC_H */

#ifndef CONFIG_HAVE_ARCH_WITHIN_STACK_FRAMES
static inline int arch_within_stack_frames(const void * const stack,