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Merge branch 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip

Pull timer updates from Thomas Gleixner:
 "The time/timekeeping/timer folks deliver with this update:

   - Fix a reintroduced signed/unsigned issue and cleanup the whole
     signed/unsigned mess in the timekeeping core so this wont happen
     accidentaly again.

   - Add a new trace clock based on boot time

   - Prevent injection of random sleep times when PM tracing abuses the
     RTC for storage

   - Make posix timers configurable for real tiny systems

   - Add tracepoints for the alarm timer subsystem so timer based
     suspend wakeups can be instrumented

   - The usual pile of fixes and updates to core and drivers"

* 'timers-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (23 commits)
  timekeeping: Use mul_u64_u32_shr() instead of open coding it
  timekeeping: Get rid of pointless typecasts
  timekeeping: Make the conversion call chain consistently unsigned
  timekeeping_Force_unsigned_clocksource_to_nanoseconds_conversion
  alarmtimer: Add tracepoints for alarm timers
  trace: Update documentation for mono, mono_raw and boot clock
  trace: Add an option for boot clock as trace clock
  timekeeping: Add a fast and NMI safe boot clock
  timekeeping/clocksource_cyc2ns: Document intended range limitation
  timekeeping: Ignore the bogus sleep time if pm_trace is enabled
  selftests/timers: Fix spelling mistake "Asyncrhonous" -> "Asynchronous"
  clocksource/drivers/bcm2835_timer: Unmap region obtained by of_iomap
  clocksource/drivers/arm_arch_timer: Map frame with of_io_request_and_map()
  arm64: dts: rockchip: Arch counter doesn't tick in system suspend
  clocksource/drivers/arm_arch_timer: Don't assume clock runs in suspend
  posix-timers: Make them configurable
  posix_cpu_timers: Move the add_device_randomness() call to a proper place
  timer: Move sys_alarm from timer.c to itimer.c
  ptp_clock: Allow for it to be optional
  Kconfig: Regenerate *.c_shipped files after previous changes
  ...
This commit is contained in:
Linus Torvalds
2016-12-12 19:56:15 -08:00
61 changed files with 1548 additions and 1110 deletions

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@@ -38,6 +38,11 @@ to deliver its interrupts via SPIs.
architecturally-defined reset values. Only supported for 32-bit
systems which follow the ARMv7 architected reset values.
- arm,no-tick-in-suspend : The main counter does not tick when the system is in
low-power system suspend on some SoCs. This behavior does not match the
Architecture Reference Manual's specification that the system counter "must
be implemented in an always-on power domain."
Example:

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@@ -113,6 +113,34 @@ applicable everywhere (see syntax).
That will limit the usefulness but on the other hand avoid
the illegal configurations all over.
- weak reverse dependencies: "imply" <symbol> ["if" <expr>]
This is similar to "select" as it enforces a lower limit on another
symbol except that the "implied" symbol's value may still be set to n
from a direct dependency or with a visible prompt.
Given the following example:
config FOO
tristate
imply BAZ
config BAZ
tristate
depends on BAR
The following values are possible:
FOO BAR BAZ's default choice for BAZ
--- --- ------------- --------------
n y n N/m/y
m y m M/y/n
y y y Y/n
y n * N
This is useful e.g. with multiple drivers that want to indicate their
ability to hook into a secondary subsystem while allowing the user to
configure that subsystem out without also having to unset these drivers.
- limiting menu display: "visible if" <expr>
This attribute is only applicable to menu blocks, if the condition is
false, the menu block is not displayed to the user (the symbols
@@ -481,6 +509,7 @@ historical issues resolved through these different solutions.
b) Match dependency semantics:
b1) Swap all "select FOO" to "depends on FOO" or,
b2) Swap all "depends on FOO" to "select FOO"
c) Consider the use of "imply" instead of "select"
The resolution to a) can be tested with the sample Kconfig file
Documentation/kbuild/Kconfig.recursion-issue-01 through the removal

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@@ -362,6 +362,26 @@ of ftrace. Here is a list of some of the key files:
to correlate events across hypervisor/guest if
tb_offset is known.
mono: This uses the fast monotonic clock (CLOCK_MONOTONIC)
which is monotonic and is subject to NTP rate adjustments.
mono_raw:
This is the raw monotonic clock (CLOCK_MONOTONIC_RAW)
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.
To set a clock, simply echo the clock name into this file.
echo global > trace_clock