lkml.org 
[lkml]   [2017]   [Aug]   [14]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
Subject[PATCH v4 0/2] Early boot time stamps for x86
Date
changelog
---------
v3 - v4
- Fixed tsc_early_fini() call to be in the 2nd patch as reported
by Dou Liyang
- Improved comment before __use_sched_clock_early to explain why
we need both booleans.
- Simplified valid_clock logic in read_boot_clock64().

v2 - v3
- Addressed comment from Thomas Gleixner
- Timestamps are available a little later in boot but still much
earlier than in mainline. This significantly simplified this
work.
v1 - v2
In patch "x86/tsc: tsc early":
- added tsc_adjusted_early()
- fixed 32-bit compile error use do_div()

Adding early boot time stamps support for x86 machines.
SPARC patches for early boot time stamps are already integrated into
mainline linux.

Sample output
-------------
Before:
https://hastebin.com/jadaqukubu.scala

After:
https://hastebin.com/nubipozacu.scala

As seen above, currently timestamps are available from around the time when
"Security Framework" is initialized. But, 26s already passed until we
reached to this point.

Pavel Tatashin (2):
sched/clock: interface to allow timestamps early in boot
x86/tsc: use tsc early

arch/x86/include/asm/tsc.h | 4 +++
arch/x86/kernel/setup.c | 10 +++++--
arch/x86/kernel/time.c | 24 +++++++++++++++++
arch/x86/kernel/tsc.c | 47 +++++++++++++++++++++++++++++++++
include/linux/sched/clock.h | 4 +++
kernel/sched/clock.c | 63 ++++++++++++++++++++++++++++++++++++++++++++-
6 files changed, 149 insertions(+), 3 deletions(-)

--
2.14.1

\
 
 \ /
  Last update: 2017-08-14 21:14    [W:0.116 / U:0.120 seconds]
©2003-2017 Jasper Spaans. hosted at Digital OceanAdvertise on this site