05 Apr, 2007
1 commit
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In debugging a problem w/ the -rt tree, I noticed that on systems that mark
the tsc as unstable before it is registered, the TSC would still be
selected and used for a short period of time. Digging in it looks to be a
result of the mix of the clocksource list changes and my clocksource
initialization changes.With the -rt tree, using a bad TSC, even for a short period of time can
results in a hang at boot. I was not able to reproduce this hang w/
mainline, but I'm not completely certain that someone won't trip on it.This patch resolves the issue by initializing the jiffies clocksource
earlier so a bad TSC won't get selected just because nothing else is yet
registered.Signed-off-by: John Stultz
Acked-by: Thomas Gleixner
Cc: Ingo Molnar
Cc: Andi Kleen
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Feb, 2007
1 commit
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Using a flag filed allows to encode more than one information into a variable.
Preparatory patch for the generic clocksource verification.[mingo@elte.hu: convert vmitime.c to the new clocksource flag]
Signed-off-by: Thomas Gleixner
Signed-off-by: Ingo Molnar
Cc: john stultz
Cc: Roman Zippel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
17 Oct, 2006
1 commit
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Avoid possible PIT livelock issues seen on SMP systems (and reported by
Andi), by not allowing it as a clocksource on SMP boxes.However, since the PIT may no longer be present, we have to properly handle
the cases where SMP systems have TSC skew and fall back from the TSC.
Since the PIT isn't there, it would "fall back" to the TSC again. So this
changes the jiffies rating to 1, and the TSC-bad rating value to 0.Thus you will get the following behavior priority on i386 systems:
tsc [if present & stable]
hpet [if present]
cyclone [if present]
acpi_pm [if present]
pit [if UP]
jiffiesRather then the current more complicated:
tsc [if present & stable]
hpet [if present]
cyclone [if present]
acpi_pm [if present]
pit [if cpus < 4]
tsc [if present & unstable]
jiffiesSigned-off-by: John Stultz
Cc: Andi Kleen
Cc: Ingo Molnar
Cc: Thomas Gleixner
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds
27 Jun, 2006
2 commits
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As suggested by Roman Zippel, change clocksource functions to use
clocksource_xyz rather then xyz_clocksource to avoid polluting the
namespace.Signed-off-by: John Stultz
Cc: Roman Zippel
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds -
This introduces the clocksource management infrastructure. A clocksource is a
driver-like architecture generic abstraction of a free-running counter. This
code defines the clocksource structure, and provides management code for
registering, selecting, accessing and scaling clocksources.Additionally, this includes the trivial jiffies clocksource, a lowest common
denominator clocksource, provided mainly for use as an example.[hirofumi@mail.parknet.co.jp: Don't enable IRQ too early]
Signed-off-by: John Stultz
Signed-off-by: Ingo Molnar
Signed-off-by: Paul Mundt
Signed-off-by: John Stultz
Signed-off-by: OGAWA Hirofumi
Signed-off-by: Andrew Morton
Signed-off-by: Linus Torvalds