[v3 0/2] Early boot time stamps for x86
From: Pavel Tatashin
Date: Fri Aug 11 2017 - 14:51:48 EST
Resending, fixed the subject.
changelog
---------
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 | 22 ++++++++++++++++
arch/x86/kernel/tsc.c | 47 ++++++++++++++++++++++++++++++++++
include/linux/sched/clock.h | 4 +++
kernel/sched/clock.c | 61 ++++++++++++++++++++++++++++++++++++++++++++-
6 files changed, 145 insertions(+), 3 deletions(-)
--
2.14.0