From: Thomas Gleixner <tglx@linutronix.de>
To: LKML <linux-kernel@vger.kernel.org>
Cc: Linus Torvalds <torvalds@linuxfoundation.org>,
Ingo Molnar <mingo@kernel.org>,
Peter Zijlstra <peterz@infradead.org>,
Steven Rostedt <rostedt@goodmis.org>,
John Stultz <john.stultz@linaro.org>,
Petr Mladek <pmladek@suse.com>,
Mark Salyzyn <salyzyn@android.com>,
Prarit Bhargava <prarit@redhat.com>,
Sergey Senozhatsky <sergey.senozhatsky@gmail.com>,
Dmitry Torokhov <dmitry.torokhov@gmail.com>,
Kevin Easton <kevin@guarana.org>,
Michael Kerrisk <mtk.manpages@gmail.com>,
Jonathan Corbet <corbet@lwn.net>
Subject: [RFC/RFT patch 7/7] tracing: Conflate boot and monotonic clock
Date: Thu, 01 Mar 2018 17:33:38 +0100 [thread overview]
Message-ID: <20180301165150.489635255@linutronix.de> (raw)
In-Reply-To: 20180301163331.987775783@linutronix.de
[-- Attachment #1: tracing--Conflate-boot-and-monotonic-clock.patch --]
[-- Type: text/plain, Size: 2263 bytes --]
Conflate boot and mono trace clocks and document the new behaviour.
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Steven Rostedt <rostedt@goodmis.org>
---
Documentation/trace/ftrace.txt | 14 +++-----------
include/linux/timekeeping.h | 6 ------
kernel/trace/trace.c | 2 +-
3 files changed, 4 insertions(+), 18 deletions(-)
--- a/Documentation/trace/ftrace.txt
+++ b/Documentation/trace/ftrace.txt
@@ -449,17 +449,9 @@ After mounting tracefs you will have acc
which is montonic but is not subject to any rate adjustments
and ticks at the same rate as the hardware clocksource.
- boot: This is the boot clock (CLOCK_BOOTTIME) and is based on the
- fast monotonic clock, but also accounts for time spent in
- suspend. Since the clock access is designed for use in
- tracing in the suspend path, some side effects are possible
- if clock is accessed after the suspend time is accounted before
- the fast mono clock is updated. In this case, the clock update
- appears to happen slightly sooner than it normally would have.
- Also on 32-bit systems, it's possible that the 64-bit boot offset
- sees a partial update. These effects are rare and post
- processing should be able to handle them. See comments in the
- ktime_get_boot_fast_ns() function for more information.
+ boot: Same as mono. Used to be a separate clock which accounted
+ for the time spent in suspend while CLOCK_MONOTONIC did
+ not.
To set a clock, simply echo the clock name into this file.
--- a/include/linux/timekeeping.h
+++ b/include/linux/timekeeping.h
@@ -113,12 +113,6 @@ extern u64 ktime_get_mono_fast_ns(void);
extern u64 ktime_get_raw_fast_ns(void);
extern u64 ktime_get_real_fast_ns(void);
-/* Clock BOOTTIME compatibility wrappers */
-static inline u64 ktime_get_boot_fast_ns(void)
-{
- return ktime_get_mono_fast_ns();
-}
-
/*
* timespec64 interfaces utilizing the ktime based ones
*/
--- a/kernel/trace/trace.c
+++ b/kernel/trace/trace.c
@@ -1164,7 +1164,7 @@ static struct {
{ trace_clock, "perf", 1 },
{ ktime_get_mono_fast_ns, "mono", 1 },
{ ktime_get_raw_fast_ns, "mono_raw", 1 },
- { ktime_get_boot_fast_ns, "boot", 1 },
+ { ktime_get_mono_fast_ns, "boot", 1 },
ARCH_TRACE_CLOCKS
};
next prev parent reply other threads:[~2018-03-01 16:57 UTC|newest]
Thread overview: 40+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-03-01 16:33 [RFC/RFT patch 0/7] timekeeping: Unify clock MONOTONIC and clock BOOTTIME Thomas Gleixner
2018-03-01 16:33 ` [RFC/RFT patch 1/7] timekeeping: Provide CLOCK_MONOTONIC_ACTIVE Thomas Gleixner
2018-03-13 7:06 ` [tip:timers/core] timekeeping: Add the new CLOCK_MONOTONIC_ACTIVE clock tip-bot for Thomas Gleixner
2018-03-01 16:33 ` [RFC/RFT patch 2/7] timekeeping: Make clock MONOTONIC behave like clock BOOTTIME Thomas Gleixner
2018-03-13 7:07 ` [tip:timers/core] timekeeping: Make the MONOTONIC clock behave like the BOOTTIME clock tip-bot for Thomas Gleixner
2018-03-01 16:33 ` [RFC/RFT patch 3/7] Input: evdev - Conflate clock MONOTONIC and BOOTTIME Thomas Gleixner
2018-03-13 7:07 ` [tip:timers/core] Input: Evdev - unify MONOTONIC and BOOTTIME clock behavior tip-bot for Thomas Gleixner
2018-03-01 16:33 ` [RFC/RFT patch 4/7] timekeeping: Remove boot time specific code Thomas Gleixner
2018-03-13 7:08 ` [tip:timers/core] " tip-bot for Thomas Gleixner
2018-03-01 16:33 ` [RFC/RFT patch 5/7] posix-timers: Conflate clock MONOTONIC and BOOTTIME Thomas Gleixner
2018-03-13 7:08 ` [tip:timers/core] posix-timers: Unify MONOTONIC and BOOTTIME clock behavior tip-bot for Thomas Gleixner
2018-03-01 16:33 ` [RFC/RFT patch 6/7] hrtimer: Conflate clock MONOTONIC and BOOTTIME Thomas Gleixner
2018-03-13 7:09 ` [tip:timers/core] hrtimer: Unify MONOTONIC and BOOTTIME clock behavior tip-bot for Thomas Gleixner
2018-03-01 16:33 ` Thomas Gleixner [this message]
2018-03-13 7:09 ` [tip:timers/core] tracing: Unify the "boot" and "mono" tracing clocks tip-bot for Thomas Gleixner
2018-03-01 17:23 ` [RFC/RFT patch 0/7] timekeeping: Unify clock MONOTONIC and clock BOOTTIME Linus Torvalds
2018-03-01 18:41 ` Thomas Gleixner
2018-03-01 18:50 ` Steven Rostedt
2018-03-01 19:10 ` Thomas Gleixner
2018-03-13 6:36 ` Ingo Molnar
2018-03-13 18:11 ` John Stultz
2018-04-20 4:37 ` David Herrmann
2018-04-20 5:44 ` Sergey Senozhatsky
2018-04-20 6:49 ` David Herrmann
2018-04-24 0:40 ` Genki Sky
2018-04-24 2:45 ` Genki Sky
2018-04-24 3:03 ` John Stultz
2018-04-24 8:09 ` Thomas Gleixner
2018-04-24 12:11 ` Genki Sky
2018-04-24 15:00 ` Thomas Gleixner
2018-04-25 6:50 ` Pavel Machek
2018-04-25 8:55 ` Rafael J. Wysocki
2018-04-25 8:52 ` Rafael J. Wysocki
2018-04-25 9:49 ` Rafael J. Wysocki
2018-04-25 13:03 ` Thomas Gleixner
2018-04-26 7:03 ` Mike Galbraith
2018-04-26 7:42 ` Thomas Gleixner
2018-04-26 8:36 ` Rafael J. Wysocki
2018-04-26 8:51 ` Thomas Gleixner
2018-04-26 9:03 ` Rafael J. Wysocki
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