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Gregory Nutt 2016-02-19 06:52:41 -06:00
parent 94bea6547b
commit fd94d7a675
3 changed files with 30 additions and 79 deletions
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@ -1609,26 +1609,19 @@ o Linux/Cywgin simulation (arch/sim)
Status: Open
Priority: Low
Title: SMP SIMULATION INCOMPLETE
Title: SMP SIMULATION ISSUES
Description: The configuration has basic support SMP testing. The simulation
supports the emulation of multiple CPUs by creating multiple
pthreads, each run a copy of the simulation in the same process
address space.
The simulation SMP implemention is incomplete, however. Two
critical SMP functions are not implemented:
At present, the SMP simulation is not fully functional: It does
operate on the simulated CPU threads for a few context switches
then fails during a setjmp() operation. I suspect that this is
not an issue with the NuttX SMP logic but more likely some chaos
in the pthread controls.
- int up_cpu_pause(void)
- int up_cpu_resume(void)
These are used to start a new task on a different CPU: (1)
the other CPU is stopped or paused, (2) the OS datastructures
for that CPU are modified, then (2) the other CPU is resumed.
Unfortunately, I have not yet thought of a way to implement
them in the simulation.
Currently, for example, you can enable SMP for ostest
configuration by enabling:
You can enable SMP for ostest configuration by enabling:
-# CONFIG_EXPERIMENTAL is not set
+CONFIG_EXPERIMENTAL=y
@ -1638,6 +1631,13 @@ o Linux/Cywgin simulation (arch/sim)
+CONFIG_SMP_NCPUS=2
+CONFIG_SMP_IDLETHREAD_STACKSIZE=2048
You also must enable near-realtime-performance otherwise even long
timeouts will expire before a CPU thread even has a chance to
execute.
-# CONFIG_SIM_WALLTIME is not set
+CONFIG_SIM_WALLTIME=y
And you can enable some additional debug output with:
-# CONFIG_DEBUG_SCHED is not set
@ -1646,73 +1646,24 @@ o Linux/Cywgin simulation (arch/sim)
-# CONFIG_SCHED_INSTRUMENTATION is not set
+CONFIG_SCHED_INSTRUMENTATION=y
The result should be as follows:
The NSH configuration can also be forced to run SMP, but
suffers from the same quirky behavior. I can be made
reliable if you modify arch/sim/src/up_idle.c so that
the IDLE loop only runs for CPU0. Otherwise, often
simuart_post() will be called from CPU1 and it will try
to restart NSH on CPU0 and, again, the same quirkiness
occurs.
- CPU0 initializes and starts CPU1. CPU1 is running an
executing the IDLE task.
But for example, this command:
os_start: Entry
os_idletask: CPU1: Beginning Idle Loop
nsh> sleep 1 &
- CPU0 brings up the the OS test application on CPU0
will execute the sleep command on CPU1 which has worked
every time that I have tried it (which is not too many
times).
os_do_appstart: Starting init thread
CPU0: Start init, TCB@42f490, state=5
up_unblock_task: Unblocking TCB=42f490
CPU0: Suspend CPU0 IDLE, TCB@42c180, state=4
CPU0: Resume init, TCB@42f490, state=0
up_unblock_task: New Active Task TCB=42f490
- OS test runs and performs some basic checks.
stdio_test: write fd=1
stdio_test: Standard I/O Check: printf
stdio_test: write fd=2
stdio_test: Standard I/O Check: fprintf to stderr
ostest_main: putenv(Variable1=BadValue3)
up_block_task: Blocking TCB=42f490
CPU0: Suspend init, TCB@42f490, state=4
CPU0: Resume CPU0 IDLE, TCB@42c180, state=3
up_block_task: New Active Task TCB=42c180
up_unblock_task: Unblocking TCB=42f490
CPU0: Suspend CPU0 IDLE, TCB@42c180, state=4
CPU0: Resume init, TCB@42f490, state=0
up_unblock_task: New Active Task TCB=42f490
ostest_main: setenv(Variable1, GoodValue1, TRUE)
ostest_main: setenv(Variable2, BadValue1, FALSE)
ostest_main: setenv(Variable2, GoodValue2, TRUE)
ostest_main: setenv(Variable3, Variable3, FALSE)
ostest_main: setenv(Variable3, Variable3, FALSE)
show_variable: Variable=Variable1 has value=GoodValue1
show_variable: Variable=Variable2 has value=GoodValue2
show_variable: Variable=Variable3 has value=GoodValue3
- Then OS test tries to start the task ostest on CPU1
CPU0: Start ostest, TCB@430e90, state=5
up_unblock_task: Unblocking TCB=430e90
CPU1: Suspend CPU1 IDLE, TCB@42c2c0, state=4
CPU0: Resume ostest, TCB@430e90, state=0
ostest_main: Started user_main at PID=4
There is no failure but, of course, the task on CPU1 does not
run, i.e., it does not replace the IDLE task running on CPU1.
2016-02-16: The NSH configuration can be forced to run, but
only if (1) You don't try to execute built-in commands or to
execute commands in the background. Those thoses cases, it
will try to start the command on CPU1 and the same problem
as for the ostest case occurs.
Also, for NSH you have to modify arch/sim/src/up_idle.c so
that the IDLE loop only runfs for CPU0. Otherwise, often
simuart_post() will be called from CPU1 and it will try to
restart NSH on CPU0 and, again, the same problem occurs.
2016-02-18: There is an initial implementation based on
signals and signal handling, but this is not yet functional.
Status: Open
Priority: Low, SMP is important, but SMP on the simulator is not
o ARM (arch/arm/)
^^^^^^^^^^^^^^^

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Subproject commit 689e18739d4dc9d5238dd4b74e88792cfc1ec2e1
Subproject commit 6586d3eb74044666941bb29d1fd3eceee8d57483

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Subproject commit 7b89b3ddfab4fc733a81bca8db5f0277e72535de
Subproject commit 4127469e4f06fcfc21610df669337a9552165ca7