| Message ID | 1429865684-6214-1-git-send-email-naveen.n.rao@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | Accepted |
| Delegated to: | Michael Ellerman |
| Headers | show |
On Fri, 24 Apr 2015 14:24:44 +0530 "Naveen N. Rao" <naveen.n.rao@linux.vnet.ibm.com> wrote: > Add a new powerpc-specific trace clock using the timebase register, > similar to x86-tsc. This gives us > - a fast, monotonic, hardware clock source for trace entries, and > - a clock that can be used to correlate events across cpus as well as across > hypervisor and guests. > > Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> > --- > Changes since v1: > - removed unnecessary #ifdef in trace_clock.h > - changed config build dependency for trace_clock.o from TRACE_CLOCK to TRACING > Looks fine to me. Acked-by: Steven Rostedt <rostedt@goodmis.org> -- Steve > > Documentation/trace/ftrace.txt | 5 +++++ > arch/powerpc/include/asm/Kbuild | 1 - > arch/powerpc/include/asm/trace_clock.h | 19 +++++++++++++++++++ > arch/powerpc/kernel/Makefile | 1 + > arch/powerpc/kernel/trace_clock.c | 15 +++++++++++++++ > 5 files changed, 40 insertions(+), 1 deletion(-) > create mode 100644 arch/powerpc/include/asm/trace_clock.h > create mode 100644 arch/powerpc/kernel/trace_clock.c >
On 2015/04/24 02:24PM, Naveen N Rao wrote: > Add a new powerpc-specific trace clock using the timebase register, > similar to x86-tsc. This gives us > - a fast, monotonic, hardware clock source for trace entries, and > - a clock that can be used to correlate events across cpus as well as across > hypervisor and guests. > > Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> > --- > Changes since v1: > - removed unnecessary #ifdef in trace_clock.h > - changed config build dependency for trace_clock.o from TRACE_CLOCK to TRACING Bump. Michael, can you please pick this up? - Naveen
On Fri, 2015-24-04 at 08:54:44 UTC, "Naveen N. Rao" wrote: > Add a new powerpc-specific trace clock using the timebase register, > similar to x86-tsc. This gives us > - a fast, monotonic, hardware clock source for trace entries, and > - a clock that can be used to correlate events across cpus as well as across > hypervisor and guests. > > Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> > Acked-by: Steven Rostedt <rostedt@goodmis.org> Applied to powerpc next, thanks. https://git.kernel.org/powerpc/c/197165d44925bd0fa892 cheers
diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index 572ca92..689f61a 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -346,6 +346,11 @@ of ftrace. Here is a list of some of the key files: x86-tsc: Architectures may define their own clocks. For example, x86 uses its own TSC cycle clock here. + ppc-tb: This uses the powerpc timebase register value. + This is in sync across CPUs and can also be used + to correlate events across hypervisor/guest if + tb_offset is known. + To set a clock, simply echo the clock name into this file. echo global > trace_clock diff --git a/arch/powerpc/include/asm/Kbuild b/arch/powerpc/include/asm/Kbuild index 382b28e..5041c66 100644 --- a/arch/powerpc/include/asm/Kbuild +++ b/arch/powerpc/include/asm/Kbuild @@ -5,5 +5,4 @@ generic-y += mcs_spinlock.h generic-y += preempt.h generic-y += rwsem.h generic-y += scatterlist.h -generic-y += trace_clock.h generic-y += vtime.h diff --git a/arch/powerpc/include/asm/trace_clock.h b/arch/powerpc/include/asm/trace_clock.h new file mode 100644 index 0000000..cf1ee75 --- /dev/null +++ b/arch/powerpc/include/asm/trace_clock.h @@ -0,0 +1,19 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation. + * + * Copyright (C) 2015 Naveen N. Rao, IBM Corporation + */ + +#ifndef _ASM_PPC_TRACE_CLOCK_H +#define _ASM_PPC_TRACE_CLOCK_H + +#include <linux/compiler.h> +#include <linux/types.h> + +extern u64 notrace trace_clock_ppc_tb(void); + +#define ARCH_TRACE_CLOCKS { trace_clock_ppc_tb, "ppc-tb", 0 }, + +#endif /* _ASM_PPC_TRACE_CLOCK_H */ diff --git a/arch/powerpc/kernel/Makefile b/arch/powerpc/kernel/Makefile index 502cf69..18e038e 100644 --- a/arch/powerpc/kernel/Makefile +++ b/arch/powerpc/kernel/Makefile @@ -118,6 +118,7 @@ obj-$(CONFIG_PPC_IO_WORKAROUNDS) += io-workarounds.o obj-$(CONFIG_DYNAMIC_FTRACE) += ftrace.o obj-$(CONFIG_FUNCTION_GRAPH_TRACER) += ftrace.o obj-$(CONFIG_FTRACE_SYSCALLS) += ftrace.o +obj-$(CONFIG_TRACING) += trace_clock.o ifneq ($(CONFIG_PPC_INDIRECT_PIO),y) obj-y += iomap.o diff --git a/arch/powerpc/kernel/trace_clock.c b/arch/powerpc/kernel/trace_clock.c new file mode 100644 index 0000000..4917069 --- /dev/null +++ b/arch/powerpc/kernel/trace_clock.c @@ -0,0 +1,15 @@ +/* + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License, version 2, as + * published by the Free Software Foundation. + * + * Copyright (C) 2015 Naveen N. Rao, IBM Corporation + */ + +#include <asm/trace_clock.h> +#include <asm/time.h> + +u64 notrace trace_clock_ppc_tb(void) +{ + return get_tb(); +}
Add a new powerpc-specific trace clock using the timebase register, similar to x86-tsc. This gives us - a fast, monotonic, hardware clock source for trace entries, and - a clock that can be used to correlate events across cpus as well as across hypervisor and guests. Signed-off-by: Naveen N. Rao <naveen.n.rao@linux.vnet.ibm.com> --- Changes since v1: - removed unnecessary #ifdef in trace_clock.h - changed config build dependency for trace_clock.o from TRACE_CLOCK to TRACING Documentation/trace/ftrace.txt | 5 +++++ arch/powerpc/include/asm/Kbuild | 1 - arch/powerpc/include/asm/trace_clock.h | 19 +++++++++++++++++++ arch/powerpc/kernel/Makefile | 1 + arch/powerpc/kernel/trace_clock.c | 15 +++++++++++++++ 5 files changed, 40 insertions(+), 1 deletion(-) create mode 100644 arch/powerpc/include/asm/trace_clock.h create mode 100644 arch/powerpc/kernel/trace_clock.c