diff options
author | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-12 19:56:15 -0800 |
---|---|---|
committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-12-12 19:56:15 -0800 |
commit | 9465d9cc31fa732089cd8bec9f1bdfcdc174a5ce (patch) | |
tree | fb31a0a6271b255ffe6e29b4f9eb4192253f8c7f /Documentation | |
parent | e71c3978d6f97659f6c3ee942c3e581299e4adf2 (diff) | |
parent | c029a2bec66e42e57538cb65e28618baf6a4b311 (diff) |
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
...
Diffstat (limited to 'Documentation')
-rw-r--r-- | Documentation/devicetree/bindings/arm/arch_timer.txt | 5 | ||||
-rw-r--r-- | Documentation/kbuild/kconfig-language.txt | 29 | ||||
-rw-r--r-- | Documentation/trace/ftrace.txt | 20 |
3 files changed, 54 insertions, 0 deletions
diff --git a/Documentation/devicetree/bindings/arm/arch_timer.txt b/Documentation/devicetree/bindings/arm/arch_timer.txt index ef5fbe9a77c7..ad440a2b8051 100644 --- a/Documentation/devicetree/bindings/arm/arch_timer.txt +++ b/Documentation/devicetree/bindings/arm/arch_timer.txt @@ -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: diff --git a/Documentation/kbuild/kconfig-language.txt b/Documentation/kbuild/kconfig-language.txt index 069fcb3eef6e..262722d8867b 100644 --- a/Documentation/kbuild/kconfig-language.txt +++ b/Documentation/kbuild/kconfig-language.txt @@ -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 diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index 185c39fea2a0..5596e2d71d6d 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -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 |