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>
This is a start to move away from the C99 {u}int{8,16,32,64}_t types to
Zephyr defined u{8,16,32,64}_t and s{8,16,32,64}_t. This allows Zephyr
to define the sized types in a consistent manor across all the
architectures we support and not conflict with what various compilers
and libc might do with regards to the C99 types.
We introduce <zephyr/types.h> as part of this and have it include
<stdint.h> for now until we transition all the code away from the C99
types.
We go with u{8,16,32,64}_t and s{8,16,32,64}_t as there are some
existing variables defined u8 & u16 as well as to be consistent with
Zephyr naming conventions.
Jira: ZEP-2051
Change-Id: I451fed0623b029d65866622e478225dfab2c0ca8
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>
Also fixes up Kernel Primer examples to use these macros.
Change-Id: Ib1bc9e3f85ab75f81986bc3930fb287266a886b5
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
As for SECONDS() and MSEC, now sys_clock.h provides a USEC() macro.
Change-Id: I43e8b132d2deeb862d8cfda1f785115f339d6ddb
Signed-off-by: Tomasz Bursztyka <tomasz.bursztyka@linux.intel.com>
Adds extern "C" { } blocks to header files so that they can be
safely used by C++ source files.
Change-Id: Ia4db0c36a5dac5d3de351184a297d2af0df64532
Signed-off-by: Peter Mitsis <peter.mitsis@windriver.com>
Removed old style file description and documnetation and apply
doxygen synatx.
Change-Id: I3ac9f06d4f574bf3c79c6f6044cec3a7e2f6e4c8
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Renames nanokernel global variable _nano_ticks to _sys_clock_tick_count.
Change-Id: I857407f1f7e8d9fd2eedc1c1696851173e58d2b4
Signed-off-by: Peter Mitsis <peter.mitsis@windriver.com>
Some timer devices, such as the HPET, read their frequencies at runtime.
All global constant values must be set at runtime in that case.
Change-Id: I408babce6deb857748a87691132d7e27e88f0bb8
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Change-Id: I6da43e41f9c6efee577b70513ec368ae3cce0144
Signed-off-by: Dan Kalowsky <daniel.kalowsky@intel.com>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Change all the Intel and Wind River code license from BSD-3 to Apache 2.
Change-Id: Id8be2c1c161a06ea8a0b9f38e17660e11dbb384b
Signed-off-by: Javier B Perez Hernandez <javier.b.perez.hernandez@linux.intel.com>
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Change-Id: I0ae05d1b9f871b7b832581552442409233cdec5e
Original-work-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Make these public:
- SECONDS(x): macro that gives the number of ticks in x seconds
- MSEC(x): macro that gives the number of ticks in x milliseconds
- MSEC_PER_SEC: number of milliseconds per second
- USEC_PER_MSEC: number of microseconds per millisecond
Change-Id: Ic5dbf9349651a477b066edb0c6b6721da2b7e5bb
Signed-off-by: Benjamin Walsh <benjamin.walsh@windriver.com>
Fixes the SYS_CLOCK_HW_CYCLES_PER_SEC Kconfig option dependencies such that
it can be overridden by a modified platform configuration file. This is
particularly important for the LOAPIC timer driver as
SYS_CLOCK_HW_CYCLES_PER_SEC is dependent upon the target's CPU/bus frequency.
Change-Id: I0fb49b4c540888cb1988c76e2a711a85e756f82c
Signed-off-by: Peter Mitsis <peter.mitsis@windriver.com>
The change replaces multiple asterisks to ** at
the beginning of comments and adds a space before
the asterisks at the beginning of lines.
Change-Id: I7656bde3bf4d9a31e38941e43b580520432dabc1
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
The revised name better reflects the fact that the file defines
macros in addition to declaring variables. In addition, most of
these APIs use the "sys_clock_" prefix, which aligns well with
the new file name.
Change-Id: Ib33517d4b19ec2455303b87200c677e87640fcbc
Signed-off-by: Allan Stephens <allan.stephens@windriver.com>
Ramesh Thomas