From 81a6a146e88eca5d6726569779778d61489d85aa Mon Sep 17 00:00:00 2001 From: Li Bin Date: Fri, 4 Dec 2015 11:38:39 +0800 Subject: [PATCH] arm64: ftrace: stop using kstop_machine to enable/disable tracing For ftrace on arm64, kstop_machine which is hugely disruptive to a running system is not needed to convert nops to ftrace calls or back, because that to be modified instrucions, that NOP, B or BL, are all safe instructions which called "concurrent modification and execution of instructions", that can be executed by one thread of execution as they are being modified by another thread of execution without requiring explicit synchronization. Signed-off-by: Li Bin Reviewed-by: Steven Rostedt Signed-off-by: Will Deacon --- arch/arm64/kernel/ftrace.c | 5 +++++ 1 file changed, 5 insertions(+) diff --git a/arch/arm64/kernel/ftrace.c b/arch/arm64/kernel/ftrace.c index c851be795080..9669b331a23b 100644 --- a/arch/arm64/kernel/ftrace.c +++ b/arch/arm64/kernel/ftrace.c @@ -93,6 +93,11 @@ int ftrace_make_nop(struct module *mod, struct dyn_ftrace *rec, return ftrace_modify_code(pc, old, new, true); } +void arch_ftrace_update_code(int command) +{ + ftrace_modify_all_code(command); +} + int __init ftrace_dyn_arch_init(void) { return 0; -- 2.20.1