kernel/time/clocksource.c needs struct task_struct on m68k.
Because it uses spin_unlock_irq(), which, on m68k, uses hardirq_count(), which
uses preempt_count(), which needs to dereference struct task_struct, we
have to include sched.h. Because it would cause a loop inclusion, we
cannot include sched.h in any other of asm-m68k/system.h,
linux/thread_info.h, linux/hardirq.h, which leaves this ugly include in
a C file as the only simple solution.
Signed-off-by: Mathieu Desnoyers <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Roman Zippel <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
I notice that the code which implements adjtime clears the time_adjust
value before using it. The attached patch makes the obvious fix.
Acked-by: Roman Zippel <[email protected]>
Signed-off-by: Jim Houston <[email protected]>
Cc: John Stultz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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]
jiffies
Rather 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]
jiffies
Signed-off-by: John Stultz <[email protected]>
Cc: Andi Kleen <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This patch contains the following possible cleanups:
- make the following needlessly global function static:
- ntp_update_frequency()
- make the following needlessly global variables static:
- time_state
- time_offset
- time_constant
- time_reftime
- remove the following read-only global variable:
- time_precision
Signed-off-by: Adrian Bunk <[email protected]>
Cc: Roman Zippel <[email protected]>
Cc: john stultz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This converts the kernel ntp model into a model which matches the nanokernel
reference implementations. The previous patches already increased the
resolution and precision of the computations, so that this conversion becomes
quite simple.
<[email protected]> explains:
The original NTP kernel interface was defined in units of microseconds.
That's what Linux implements. As computers have gotten faster and can now
split microseconds easily, a new kernel interface using nanosecond units was
defined ("the nanokernel", confusing as that name is to OS hackers), and
there's an STA_NANO bit in the adjtimex() status field to tell the application
which units it's using.
The current ntpd supports both, but Linux loses some possible timing
resolution because of quantization effects, and the ntpd hackers would really
like to be able to drop the backwards compatibility code.
Ulrich Windl has been maintaining a patch set to do the conversion for years,
but it's hard to keep in sync.
Signed-off-by: Roman Zippel <[email protected]>
Cc: john stultz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This converts time_freq to a scaled nsec value and adds around 6bit of extra
resolution. This pushes the time_freq to its 32bit limits so the calculatons
have to be done with 64bit.
Signed-off-by: Roman Zippel <[email protected]>
Cc: john stultz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
time_tolerance isn't changed at all in the kernel, so simply remove it, this
simplifies the next patch, as it avoids a number of conversions.
Signed-off-by: Roman Zippel <[email protected]>
Cc: john stultz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This folds update_ntp_one_tick() into second_overflow() and adds time_adjust
to the tick length, this makes time_next_adjust unnecessary. This slightly
changes the adjtime() behaviour, instead of applying it to the next tick, it's
applied to the next second.
Signed-off-by: Roman Zippel <[email protected]>
Cc: john stultz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This converts time_offset into a scaled per tick value. This avoids now
completely the crude compensation in second_overflow().
Signed-off-by: Roman Zippel <[email protected]>
Cc: john stultz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This makes time_adj local to second_overflow() and integrates it into the tick
length instead of adding it everytime.
Signed-off-by: Roman Zippel <[email protected]>
Cc: john stultz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
This introduces ntp_update_frequency() and deinlines ntp_clear() (as it's not
performance critical). ntp_update_frequency() calculates the base tick length
using tick_usec and adds a base adjustment, in case the frequency doesn't
divide evenly by HZ.
Signed-off-by: Roman Zippel <[email protected]>
Cc: john stultz <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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 <[email protected]>
Cc: Roman Zippel <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Implement the time sources for i386 (acpi_pm, cyclone, hpet, pit, and tsc).
With this patch, the conversion of the i386 arch to the generic timekeeping
code should be complete.
The patch should be fairly straight forward, only adding the new clocksources.
[[email protected]: acpi_pm cleanup]
Signed-off-by: John Stultz <[email protected]>
Signed-off-by: Adrian Bunk <[email protected]>
Signed-off-by: Paul Mundt <[email protected]>
Signed-off-by: John Stultz <[email protected]>
Signed-off-by: OGAWA Hirofumi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Modify the update_wall_time function so it increments time using the
clocksource abstraction instead of jiffies. Since the only clocksource driver
currently provided is the jiffies clocksource, this should result in no
functional change. Additionally, a timekeeping_init and timekeeping_resume
function has been added to initialize and maintain some of the new timekeping
state.
[[email protected]: fixlet]
Signed-off-by: John Stultz <[email protected]>
Signed-off-by: OGAWA Hirofumi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
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.
[[email protected]: Don't enable IRQ too early]
Signed-off-by: John Stultz <[email protected]>
Signed-off-by: Ingo Molnar <[email protected]>
Signed-off-by: Paul Mundt <[email protected]>
Signed-off-by: John Stultz <[email protected]>
Signed-off-by: OGAWA Hirofumi <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>
Mathieu Desnoyers