From: "Steven Rostedt (Red Hat)" <[email protected]> Some callbacks of the function tracer use rcu_read_lock(). This means that there's places that can not be traced because RCU is not tracking the CPU for various reasons (like NO_HZ_FULL and coming back from userspace).
These functions need to be marked so that callbacks that use RCU do not trace them. Acked-by: H. Peter Anvin <[email protected]> Acked-by: Rafael J. Wysocki <[email protected]> Acked-by: Paul E. McKenney <[email protected]> Signed-off-by: Steven Rostedt <[email protected]> --- arch/x86/kernel/process.c | 2 ++ drivers/cpuidle/cpuidle.c | 2 ++ kernel/cpu/idle.c | 2 ++ 3 files changed, 6 insertions(+) diff --git a/arch/x86/kernel/process.c b/arch/x86/kernel/process.c index 83369e5..18739cd 100644 --- a/arch/x86/kernel/process.c +++ b/arch/x86/kernel/process.c @@ -17,6 +17,7 @@ #include <linux/stackprotector.h> #include <linux/tick.h> #include <linux/cpuidle.h> +#include <linux/ftrace.h> #include <trace/events/power.h> #include <linux/hw_breakpoint.h> #include <asm/cpu.h> @@ -316,6 +317,7 @@ void default_idle(void) #ifdef CONFIG_APM_MODULE EXPORT_SYMBOL(default_idle); #endif +FTRACE_UNSAFE_RCU(default_idle); #ifdef CONFIG_XEN bool xen_set_default_idle(void) diff --git a/drivers/cpuidle/cpuidle.c b/drivers/cpuidle/cpuidle.c index fdc432f..9515457 100644 --- a/drivers/cpuidle/cpuidle.c +++ b/drivers/cpuidle/cpuidle.c @@ -19,6 +19,7 @@ #include <linux/ktime.h> #include <linux/hrtimer.h> #include <linux/module.h> +#include <linux/ftrace.h> #include <trace/events/power.h> #include "cpuidle.h" @@ -168,6 +169,7 @@ int cpuidle_idle_call(void) return 0; } +FTRACE_UNSAFE_RCU(cpuidle_idle_call); /** * cpuidle_install_idle_handler - installs the cpuidle idle loop handler diff --git a/kernel/cpu/idle.c b/kernel/cpu/idle.c index e695c0a..d9d290f 100644 --- a/kernel/cpu/idle.c +++ b/kernel/cpu/idle.c @@ -5,6 +5,7 @@ #include <linux/cpu.h> #include <linux/tick.h> #include <linux/mm.h> +#include <linux/ftrace.h> #include <linux/stackprotector.h> #include <asm/tlb.h> @@ -61,6 +62,7 @@ void __weak arch_cpu_idle(void) cpu_idle_force_poll = 1; local_irq_enable(); } +FTRACE_UNSAFE_RCU(arch_cpu_idle); /* * Generic idle loop implementation -- 1.7.10.4 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
