zephyr

History

Andy Ross 0f444c84e5 drivers/timer: Add a standard workaround for known qemu issues Qemu doesn't like tickless. By default[1] it tries to be realtime as vied by the host CPU -- presenting read values from hardware cycle counters and interrupt timings at the appropriate real world clock times according to whatever the simulated counter frequency is. But when the host system is loaded, there is always the problem that the qemu process might not see physical CPU time for large chunks of time (i.e. a host OS scheduling quantum -- generally about the same size as guest ticks!) leading to lost cycles. When those timer interrupts are delivered by the emulated hardware at fixed frequencies without software intervention, that's not so bad: the work the guest has to do after the interrupt generally happens synchronously (because the qemu process has just started running) and nothing notices the dropout. But with tickless, the interrupts need to be explicitly programmed by guest software! That means the driver needs to be sure it's going to get some real CPU time within some small fraction of a Zephyr tick of the right time, otherwise the computations get wonky. The end result is that qemu tends to work with tickless well on an unloaded/idle run, but not in situations (like sanitycheck) where it needs to content with other processes for host CPU. So, add a flag that drivers can use to "fake" tickless behavior when run under qemu (only), and enable it (only!) for the small handful of tests that are having trouble. [1] There is an -icount feature to implement proper cycle counting at the expense of real-world-time correspondence. Maybe someday we might get it to work for us. Signed-off-by: Andy Ross <andrew.j.ross@intel.com>		2018-11-13 17:10:07 -05:00
..
src	tests: kernel: Do not use exact time in timing checks.	2018-08-14 07:18:44 -07:00
CMakeLists.txt	samples, tests: Use semi-accurate project names	2018-10-27 21:31:25 -04:00
prj.conf	drivers/timer: Add a standard workaround for known qemu issues	2018-11-13 17:10:07 -05:00
README.txt	cleanup: remove nanokernel/nano leftovers	2017-12-05 09:44:23 -06:00
testcase.yaml	tests: remove bat_commit, replace core with kernel	2018-10-16 09:17:51 -04:00

README.txt

Title: Test workqeue APIs

Description:

A simple application verifying the workqueue API

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Building and Running Project:

This kernel project outputs to the console.  It can be built and executed
on QEMU as follows:

    make run

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Troubleshooting:

Problems caused by out-dated project information can be addressed by
issuing one of the following commands then rebuilding the project:

    make clean          # discard results of previous builds
                        # but keep existing configuration info
or
    make pristine       # discard results of previous builds
                        # and restore pre-defined configuration info

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***** BOOTING ZEPHYR OS vxxxx - BUILD: xxxxx *****
Starting sequence test
 - Initializing test items
 - Submitting test items
 - Submitting work 1 from preempt thread
 - Running test item 1
 - Submitting work 2 from coop thread
 - Submitting work 3 from preempt thread
 - Submitting work 4 from coop thread
 - Running test item 2
 - Submitting work 5 from preempt thread
 - Submitting work 6 from coop thread
 - Waiting for work to finish
 - Running test item 3
 - Running test item 4
 - Running test item 5
 - Running test item 6
 - Checking results
Starting resubmit test
 - Submitting work
 - Waiting for work to finish
 - Resubmitting work
 - Resubmitting work
 - Resubmitting work
 - Resubmitting work
 - Resubmitting work
 - Checking results
Starting delayed test
 - Initializing delayed test items
 - Submitting delayed test items
 - Submitting delayed work 1 from preempt thread
 - Submitting delayed work 3 from preempt thread
 - Submitting delayed work 5 from preempt thread
 - Waiting for delayed work to finish
 - Submitting delayed work 2 from coop thread
 - Submitting delayed work 4 from coop thread
 - Submitting delayed work 6 from coop thread
 - Running delayed test item 1
 - Running delayed test item 2
 - Running delayed test item 3
 - Running delayed test item 4
 - Running delayed test item 5
 - Running delayed test item 6
 - Checking results
Starting delayed resubmit test
 - Submitting delayed work
 - Waiting for work to finish
 - Resubmitting delayed work
 - Resubmitting delayed work
 - Resubmitting delayed work
 - Resubmitting delayed work
 - Resubmitting delayed work
 - Checking results
Starting delayed resubmit from coop thread test
 - Resubmitting delayed work with 1 ms
 - Resubmitting delayed work with 1 ms
 - Resubmitting delayed work with 1 ms
 - Resubmitting delayed work with 1 ms
 - Resubmitting delayed work with 1 ms
 - Resubmitting delayed work with 1 ms
 - Waiting for work to finish
 - Running delayed test item 1
 - Checking results
Starting delayed cancel test
 - Cancel delayed work from preempt thread
 - Cancel delayed work from coop thread
 - Cancel pending delayed work from coop thread
 - Waiting for work to finish
 - Checking results
===================================================================
PASS - main.
===================================================================
PROJECT EXECUTION SUCCESSFUL