Adds event based scheduling logic to the kernel. Updates
management of timeouts, timers, idling etc. based on
time tracked at events rather than periodic ticks. Provides
interfaces for timers to announce and get next timer expiry
based on kernel scheduling decisions involving time slicing
of threads, timeouts and idling. Uses wall time units instead
of ticks in all scheduling activities.
The implementation involves changes in the following areas
1. Management of time in wall units like ms/us instead of ticks
The existing implementation already had an option to configure
number of ticks in a second. The new implementation builds on
top of that feature and provides option to set the size of the
scheduling granurality to mili seconds or micro seconds. This
allows most of the current implementation to be reused. Due to
this re-use and co-existence with tick based kernel, the names
of variables may contain the word "tick". However, in the
tickless kernel implementation, it represents the currently
configured time unit, which would be be mili seconds or
micro seconds. The APIs that take time as a parameter are not
impacted and they continue to pass time in mili seconds.
2. Timers would not be programmed in periodic mode
generating ticks. Instead they would be programmed in one
shot mode to generate events at the time the kernel scheduler
needs to gain control for its scheduling activities like
timers, timeouts, time slicing, idling etc.
3. The scheduler provides interfaces that the timer drivers
use to announce elapsed time and get the next time the scheduler
needs a timer event. It is possible that the scheduler may not
need another timer event, in which case the system would wait
for a non-timer event to wake it up if it is idling.
4. New APIs are defined to be implemented by timer drivers. Also
they need to handler timer events differently. These changes
have been done in the HPET timer driver. In future other timers
that support tickles kernel should implement these APIs as well.
These APIs are to re-program the timer, update and announce
elapsed time.
5. Philosopher and timer_api applications have been enabled to
test tickless kernel. Separate configuration files are created
which define the necessary CONFIG flags. Run these apps using
following command
make pristine && make BOARD=qemu_x86 CONF_FILE=prj_tickless.conf qemu
Jira: ZEP-339 ZEP-1946 ZEP-948
Change-Id: I7d950c31bf1ff929a9066fad42c2f0559a2e5983
Signed-off-by: Ramesh Thomas <ramesh.thomas@intel.com>
Convert code to use u{8,16,32,64}_t and s{8,16,32,64}_t instead of C99
integer types. This handles the remaining includes and kernel, plus
touching up various points that we skipped because of include
dependancies. We also convert the PRI printf formatters in the arch
code over to normal formatters.
Jira: ZEP-2051
Change-Id: Iecbb12601a3ee4ea936fd7ddea37788a645b08b0
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Convert code to use u{8,16,32,64}_t and s{8,16,32,64}_t instead of C99
integer types.
Jira: ZEP-2051
Change-Id: I08f51e2bfd475f6245771c1bd2df7ffc744c48c4
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Clear pending IRQ when starting and restore back the RTC1 state when
disabling sys_clock, to avoid issues when soft rebooting the device or
chainloading another Zephyr image (e.g. mcuboot).
Change-Id: I693d9168196ad2cfb8475ecfa2051eac043b1fbd
Signed-off-by: Ricardo Salveti <ricardo.salveti@linaro.org>
Fixes an unlikely issue that could arise if the RTC handler in the nRF RTC
driver was blocked for more than one sys tick interval. This could lead to
_sys_clock_tick_announce() being called with more than one sys tick when the
kernel did not expect it.
Jira: ZEP-1763
Change-ID: I5608fca6f0ac97a17c1ce452c1c5c67696a49a9a
Signed-off-by: Øyvind Hovdsveen <oyvind.hovdsveen@nordicsemi.no>
This is a reworked version of the previous RTC driver. The main
changed is related to the handling _timer_idle_exit() on non-RTC
wake-ups. The previous version didn't announce the elapsed time
to the kernel in _timer_idle_exit(). Additionally, the driver now
makes sure never to announce more idle ticks than the kernel asked
for, since the kernel does not handle negative deltas in its timeout
queues.
Change-Id: I312a357a7ce8f0c22adf5153731064b92870e47e
Signed-off-by: Wojciech Bober <wojciech.bober@nordicsemi.no>
Signed-off-by: Øyvind Hovdsveen <oyvind.hovdsveen@nordicsemi.no>
Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
Some arches may want to define this as an inline function, or
define in core arch code instead of timer driver code.
Unfortunately, this means we need to remove from the footprint
tests, but this is not typically a large function.
Issue: ZEP-1546
Change-Id: Ic0d7a33507da855995838f4703d872cd613a2ca2
Signed-off-by: Andrew Boie <andrew.p.boie@intel.com>
Convert driver to use the CMSIS NVIC APIs rather than the internal ones
so we can remove them in the future.
Change-Id: I31c2f37bc0aa35668a441f4ef2821b768dd7b817
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
Replace the existing Apache 2.0 boilerplate header with an SPDX tag
throughout the zephyr code tree. This patch was generated via a
script run over the master branch.
Also updated doc/porting/application.rst that had a dependency on
line numbers in a literal include.
Manually updated subsys/logging/sys_log.c that had a malformed
header in the original file. Also cleanup several cases that already
had a SPDX tag and we either got a duplicate or missed updating.
Jira: ZEP-1457
Change-Id: I6131a1d4ee0e58f5b938300c2d2fc77d2e69572c
Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
Signed-off-by: Kumar Gala <kumar.gala@linaro.org>
The nRF RTC driver, which is used a system clock driver due to the lack
of SysTick hardware on the SoC, was using too much CPU time in its
_timer_idle_exit() implementation due to the use of 64-bit arithmetical
operations. This was causing the ISR wrapper to add excessive latency to
critical interrupts, causing BLE controller asserts.
This patch addresses the issue by using exclusively RTC ticks instead of
OS ticks, thus avoiding the necessity to convert during
_timer_idle_exit() calls, which are the most critical to interrupt
latency.
In addition the driver is now able to detect setting tick events in the
past due to it being interrupted by a higher priority context, and will
reschedule and trigger the ISR at the same time.
Change-id: I56a3be96b9fdd554c3650012d647af2f0415eb8a
Signed-off-by: Vinayak Chettimada <vinayak.kariappa.chettimada@nordicsemi.no>
Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
The nRF5x series SoCs do not implement systick, hence we disable
CORTEX_M_SYSTICK.
Instead, use nRF SoC Series NRF_RTC1 for system clock interfaces.
The kernel system clock interface is implemented using the low
power real time counter NRF_RTC1. NRF_RTC0 is used by the BLE
controller.
In addition, cleanup nRF5x series defconfig to be consistent.
Jira: ZEP-742
Jira: ZEP-1308
Jira: ZEP-1315
Change-id: I0f6cc1836fe0820a65f2cbb02cf5ae7e9eb92e1d
Signed-off-by: Vinayak Chettimada <vinayak.kariappa.chettimada@nordicsemi.no>
Signed-off-by: Carles Cufi <carles.cufi@nordicsemi.no>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
