From d2bb0762993e11363d8343127516b8fe88f9006f Mon Sep 17 00:00:00 2001 From: Wu Zhangjin Date: Fri, 20 Nov 2009 20:34:29 +0800 Subject: MIPS: Tracing: Add static function tracer support for MIPS If -pg of gcc is enabled with CONFIG_FUNCTION_TRACER=y. a calling to _mcount will be inserted into each kernel function. so, there is a possibility to trace the kernel functions in _mcount. This patch add the MIPS specific _mcount support for static function tracing. by default, ftrace_trace_function is initialized as ftrace_stub(an empty function), so, the default _mcount will introduce very little overhead. after enabling ftrace in user-space, it will jump to a real tracing function and do static function tracing for us. and -ffunction-sections is incompatible with -pg, so, disable it when ftracer is enabled. Signed-off-by: Wu Zhangjin Reviewed-by: Steven Rostedt Cc: Nicholas Mc Guire Cc: zhangfx@lemote.com Cc: Wu Zhangjin Cc: Ingo Molnar Cc: Thomas Gleixner Cc: Frederic Weisbecker Cc: linux-kernel@vger.kernel.org Cc: linux-mips@linux-mips.org Patchwork: http://patchwork.linux-mips.org/patch/672/ Signed-off-by: Ralf Baechle --- arch/mips/kernel/Makefile | 6 ++++++ 1 file changed, 6 insertions(+) (limited to 'arch/mips/kernel/Makefile') diff --git a/arch/mips/kernel/Makefile b/arch/mips/kernel/Makefile index f442de804d8..1340ba3dd38 100644 --- a/arch/mips/kernel/Makefile +++ b/arch/mips/kernel/Makefile @@ -10,6 +10,10 @@ obj-y += cpu-probe.o branch.o entry.o genex.o irq.o process.o \ ptrace.o reset.o setup.o signal.o syscall.o \ time.o topology.o traps.o unaligned.o watch.o +ifdef CONFIG_FUNCTION_TRACER +CFLAGS_REMOVE_early_printk.o = -pg +endif + obj-$(CONFIG_CEVT_BCM1480) += cevt-bcm1480.o obj-$(CONFIG_CEVT_R4K_LIB) += cevt-r4k.o obj-$(CONFIG_MIPS_MT_SMTC) += cevt-smtc.o @@ -27,6 +31,8 @@ obj-$(CONFIG_SYNC_R4K) += sync-r4k.o obj-$(CONFIG_STACKTRACE) += stacktrace.o obj-$(CONFIG_MODULES) += mips_ksyms.o module.o +obj-$(CONFIG_FUNCTION_TRACER) += mcount.o + obj-$(CONFIG_CPU_LOONGSON2) += r4k_fpu.o r4k_switch.o obj-$(CONFIG_CPU_MIPS32) += r4k_fpu.o r4k_switch.o obj-$(CONFIG_CPU_MIPS64) += r4k_fpu.o r4k_switch.o -- cgit v1.2.3-70-g09d2