The following commit has been merged into the sched/core branch of tip:
Commit-ID: e4df1511e1f4bcaa0d590aa7bbffe8bbbd6dfb49
Gitweb: https://git.kernel.org/tip/e4df1511e1f4bcaa0d590aa7bbffe8bbbd6dfb49
Author: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
AuthorDate: Thu, 12 Jan 2023 20:43:41 +01:00
Committer: Ingo Molnar <mingo@xxxxxxxxxx>
CommitterDate: Fri, 13 Jan 2023 11:48:16 +01:00
cpuidle, sched: Remove instrumentation from TIF_{POLLING_NRFLAG,NEED_RESCHED}
objtool pointed out that various idle-TIF management methods
have instrumentation:
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
Remove the instrumentation, because these methods are used in low-level
cpuidle code moving between states, that should not be instrumented.
Signed-off-by: Peter Zijlstra (Intel) <peterz@xxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx>
Tested-by: Tony Lindgren <tony@xxxxxxxxxxx>
Tested-by: Ulf Hansson <ulf.hansson@xxxxxxxxxx>
Acked-by: Rafael J. Wysocki <rafael.j.wysocki@xxxxxxxxx>
Acked-by: Frederic Weisbecker <frederic@xxxxxxxxxx>
Link: https://lore.kernel.org/r/20230112195540.988741683@xxxxxxxxxxxxx
---
include/linux/sched/idle.h | 40 +++++++++++++++++++++++++++---------
include/linux/thread_info.h | 18 +++++++++++++++-
2 files changed, 47 insertions(+), 11 deletions(-)
diff --git a/include/linux/sched/idle.h b/include/linux/sched/idle.h
index d73d314..478084f 100644
--- a/include/linux/sched/idle.h
+++ b/include/linux/sched/idle.h
@@ -23,12 +23,37 @@ static inline void wake_up_if_idle(int cpu) { }
*/
#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 *)(¤t_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 *)(¤t_thread_info()->flags));
+}
+
+#else
+
+static __always_inline void __current_set_polling(void)
+{
+ set_bit(TIF_POLLING_NRFLAG,
+ (unsigned long *)(¤t_thread_info()->flags));
+}
+
+static __always_inline void __current_clr_polling(void)
+{
+ clear_bit(TIF_POLLING_NRFLAG,
+ (unsigned long *)(¤t_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_set_polling_and_test(void)
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_clr_polling_and_test(void)
}
#endif
-static inline void current_clr_polling(void)
+static __always_inline void current_clr_polling(void)
{
__current_clr_polling();
diff --git a/include/linux/thread_info.h b/include/linux/thread_info.h
index 9f392ec..c026468 100644
--- a/include/linux/thread_info.h
+++ b/include/linux/thread_info.h
@@ -177,7 +177,23 @@ static __always_inline unsigned long read_ti_thread_flags(struct thread_info *ti
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 *)(¤t_thread_info()->flags));
+}
+
+#else
+
+static __always_inline bool tif_need_resched(void)
+{
+ return test_bit(TIF_NEED_RESCHED,
+ (unsigned long *)(¤t_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,
|