Commit 8cbd9cc6 authored by David Sharp's avatar David Sharp Committed by Steven Rostedt

tracing,x86: Add a TSC trace_clock

In order to promote interoperability between userspace tracers and ftrace,
add a trace_clock that reports raw TSC values which will then be recorded
in the ring buffer. Userspace tracers that also record TSCs are then on
exactly the same time base as the kernel and events can be unambiguously
interlaced.

Tested: Enabled a tracepoint and the "tsc" trace_clock and saw very large
timestamp values.

v2:
Move arch-specific bits out of generic code.
v3:
Rename "x86-tsc", cleanups
v7:
Generic arch bits in Kbuild.

Google-Bug-Id: 6980623
Link: http://lkml.kernel.org/r/1352837903-32191-1-git-send-email-dhsharp@google.comAcked-by: default avatarIngo Molnar <mingo@kernel.org>
Cc: Masami Hiramatsu <masami.hiramatsu.pt@hitachi.com>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: "H. Peter Anvin" <hpa@linux.intel.com>
Signed-off-by: default avatarDavid Sharp <dhsharp@google.com>
Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 7bcfaf54
......@@ -11,3 +11,4 @@ header-y += reg.h
header-y += regdef.h
header-y += sysinfo.h
generic-y += exec.h
generic-y += trace_clock.h
......@@ -31,5 +31,6 @@ generic-y += sockios.h
generic-y += termbits.h
generic-y += termios.h
generic-y += timex.h
generic-y += trace_clock.h
generic-y += types.h
generic-y += unaligned.h
......@@ -43,6 +43,7 @@ generic-y += swab.h
generic-y += termbits.h
generic-y += termios.h
generic-y += topology.h
generic-y += trace_clock.h
generic-y += types.h
generic-y += unaligned.h
generic-y += user.h
generic-y += clkdev.h
generic-y += exec.h
generic-y += trace_clock.h
......@@ -38,6 +38,7 @@ generic-y += statfs.h
generic-y += termbits.h
generic-y += termios.h
generic-y += topology.h
generic-y += trace_clock.h
generic-y += types.h
generic-y += ucontext.h
generic-y += unaligned.h
......
......@@ -49,6 +49,7 @@ generic-y += termbits.h
generic-y += termios.h
generic-y += tlbflush.h
generic-y += topology.h
generic-y += trace_clock.h
generic-y += types.h
generic-y += ucontext.h
generic-y += user.h
......
......@@ -11,3 +11,4 @@ header-y += sync_serial.h
generic-y += clkdev.h
generic-y += exec.h
generic-y += module.h
generic-y += trace_clock.h
generic-y += clkdev.h
generic-y += exec.h
generic-y += trace_clock.h
......@@ -3,3 +3,4 @@ include include/asm-generic/Kbuild.asm
generic-y += clkdev.h
generic-y += exec.h
generic-y += module.h
generic-y += trace_clock.h
......@@ -48,6 +48,7 @@ generic-y += stat.h
generic-y += termbits.h
generic-y += termios.h
generic-y += topology.h
generic-y += trace_clock.h
generic-y += types.h
generic-y += ucontext.h
generic-y += unaligned.h
......
......@@ -2,3 +2,4 @@
generic-y += clkdev.h
generic-y += exec.h
generic-y += kvm_para.h
generic-y += trace_clock.h
......@@ -3,3 +3,4 @@ include include/asm-generic/Kbuild.asm
generic-y += clkdev.h
generic-y += exec.h
generic-y += module.h
generic-y += trace_clock.h
......@@ -24,6 +24,7 @@ generic-y += sections.h
generic-y += siginfo.h
generic-y += statfs.h
generic-y += topology.h
generic-y += trace_clock.h
generic-y += types.h
generic-y += word-at-a-time.h
generic-y += xor.h
......@@ -3,3 +3,4 @@ include include/asm-generic/Kbuild.asm
header-y += elf.h
generic-y += clkdev.h
generic-y += exec.h
generic-y += trace_clock.h
# MIPS headers
generic-y += trace_clock.h
generic-y += clkdev.h
generic-y += exec.h
generic-y += trace_clock.h
......@@ -60,6 +60,7 @@ generic-y += swab.h
generic-y += termbits.h
generic-y += termios.h
generic-y += topology.h
generic-y += trace_clock.h
generic-y += types.h
generic-y += ucontext.h
generic-y += user.h
......
......@@ -3,3 +3,4 @@ generic-y += word-at-a-time.h auxvec.h user.h cputime.h emergency-restart.h \
segment.h topology.h vga.h device.h percpu.h hw_irq.h mutex.h \
div64.h irq_regs.h kdebug.h kvm_para.h local64.h local.h param.h \
poll.h xor.h clkdev.h exec.h
generic-y += trace_clock.h
......@@ -2,3 +2,4 @@
generic-y += clkdev.h
generic-y += rwsem.h
generic-y += trace_clock.h
generic-y += clkdev.h
generic-y += trace_clock.h
......@@ -3,3 +3,4 @@ include include/asm-generic/Kbuild.asm
header-y +=
generic-y += clkdev.h
generic-y += trace_clock.h
......@@ -31,5 +31,6 @@ generic-y += socket.h
generic-y += statfs.h
generic-y += termbits.h
generic-y += termios.h
generic-y += trace_clock.h
generic-y += ucontext.h
generic-y += xor.h
......@@ -8,4 +8,5 @@ generic-y += local64.h
generic-y += irq_regs.h
generic-y += local.h
generic-y += module.h
generic-y += trace_clock.h
generic-y += word-at-a-time.h
......@@ -34,5 +34,6 @@ generic-y += sockios.h
generic-y += statfs.h
generic-y += termbits.h
generic-y += termios.h
generic-y += trace_clock.h
generic-y += types.h
generic-y += xor.h
......@@ -2,3 +2,4 @@ generic-y += bug.h cputime.h device.h emergency-restart.h futex.h hardirq.h
generic-y += hw_irq.h irq_regs.h kdebug.h percpu.h sections.h topology.h xor.h
generic-y += ftrace.h pci.h io.h param.h delay.h mutex.h current.h exec.h
generic-y += switch_to.h clkdev.h
generic-y += trace_clock.h
......@@ -54,6 +54,7 @@ generic-y += syscalls.h
generic-y += termbits.h
generic-y += termios.h
generic-y += topology.h
generic-y += trace_clock.h
generic-y += types.h
generic-y += ucontext.h
generic-y += unaligned.h
......
#ifndef _ASM_X86_TRACE_CLOCK_H
#define _ASM_X86_TRACE_CLOCK_H
#include <linux/compiler.h>
#include <linux/types.h>
#ifdef CONFIG_X86_TSC
extern u64 notrace trace_clock_x86_tsc(void);
# define ARCH_TRACE_CLOCKS \
{ trace_clock_x86_tsc, "x86-tsc" },
#else /* !CONFIG_X86_TSC */
#define ARCH_TRACE_CLOCKS
#endif
#endif /* _ASM_X86_TRACE_CLOCK_H */
......@@ -61,6 +61,7 @@ obj-$(CONFIG_X86_REBOOTFIXUPS) += reboot_fixups_32.o
obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o
obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o
obj-$(CONFIG_FTRACE_SYSCALLS) += ftrace.o
obj-$(CONFIG_X86_TSC) += trace_clock.o
obj-$(CONFIG_KEXEC) += machine_kexec_$(BITS).o
obj-$(CONFIG_KEXEC) += relocate_kernel_$(BITS).o crash.o
obj-$(CONFIG_CRASH_DUMP) += crash_dump_$(BITS).o
......
/*
* X86 trace clocks
*/
#include <asm/trace_clock.h>
#include <asm/barrier.h>
#include <asm/msr.h>
/*
* trace_clock_x86_tsc(): A clock that is just the cycle counter.
*
* Unlike the other clocks, this is not in nanoseconds.
*/
u64 notrace trace_clock_x86_tsc(void)
{
u64 ret;
rdtsc_barrier();
rdtscll(ret);
return ret;
}
......@@ -25,4 +25,5 @@ generic-y += siginfo.h
generic-y += statfs.h
generic-y += termios.h
generic-y += topology.h
generic-y += trace_clock.h
generic-y += xor.h
#ifndef _ASM_GENERIC_TRACE_CLOCK_H
#define _ASM_GENERIC_TRACE_CLOCK_H
/*
* Arch-specific trace clocks.
*/
/*
* Additional trace clocks added to the trace_clocks
* array in kernel/trace/trace.c
* None if the architecture has not defined it.
*/
#ifndef ARCH_TRACE_CLOCKS
# define ARCH_TRACE_CLOCKS
#endif
#endif /* _ASM_GENERIC_TRACE_CLOCK_H */
......@@ -12,6 +12,8 @@
#include <linux/compiler.h>
#include <linux/types.h>
#include <asm/trace_clock.h>
extern u64 notrace trace_clock_local(void);
extern u64 notrace trace_clock(void);
extern u64 notrace trace_clock_global(void);
......
......@@ -488,6 +488,7 @@ static struct {
{ trace_clock_local, "local" },
{ trace_clock_global, "global" },
{ trace_clock_counter, "counter" },
ARCH_TRACE_CLOCKS
};
int trace_clock_id;
......
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