On 17.09.19 15:57, [email protected] wrote:
Hi Jan,
wow, that was a really quick response.
Does "testing latest rt release" mean that I also have to use a new Linux kernel
version?
Currently I am running linux 4.14.71-rt44.
The most recent rt-patch for linux 4.14 seems to be "patch-4.14.137-rt66.patch"
Would you recommend to use that?
I would recommend v5.2.14-rt7 to cross-check if the issue is version-agnostic.
Jan
Thanks for your comments
Jochen
>> Hello,
>>
>> I am running an Alchemy application (xenomai 3.0.9) over Linux
>> prempt-rt on a dual core
>> atom (E3930) and noticed a side effect of the Linux boot parameter
>> "rcu_nocbs".
>
>To clarify: You are using Xenomai in mercury mode (userspace libs only) on a
>stock preempt-rt kernel, right? Then a kernel splash is best reported to the
>preempt-rt community. But first make sure to have tested also the latest
release
>to clarify if that is a stable -rt issue or a general one.
>
>Jan
>
>>
>> Whenever the kernel bootparameter "rcu_nocbs=1" is set, I get the
>> following Linux
>> kernel warning, when the AlchemyTask (TestTask) is terminated.
>>
>>
>> Sep 17 13:02:43 localhost kernel: [ 97.342398] ------------[ cut here
>> ]------------
>> Sep 17 13:02:43 localhost kernel: [ 97.342412] WARNING: CPU: 0 PID:
>> 530 at
>> /home/behnkjoc/prc2020/poky/build-tca5-32/tmp/work-shared/congatec-tca5
>> -32/kernel-source/kernel/rcu/tree_plugin.h:310
>> rcu_note_context_switch+0x2a0/0x4d0
>> Sep 17 13:02:43 localhost kernel: [ 97.342414] Modules linked in:
>> ec_generic(O) ec_master(O) spidev nls_iso8859_1 cmdlinepart
>> intel_spi_platform intel_spi spi_nor mtd spi_pxa2xx_platform joydev
>> intel_rapl intel_powerclamp coretemp crc32_pclmul snd_hda_codec_hdmi
>> pcbc aesni_intel aes_i586 crypto_simd cryptd intel_cstate
>> intel_rapl_perf i2c_i801 lpc_ich pcspkr idma64 virt_dma intel_lpss_
>> pci intel_lpss input_leds mac_hid i915 video snd_hda_intel
>> drm_kms_helper snd_hda_codec snd_hda_core snd_hwdep snd_pcm
>> hid_multitouch drm mei_me snd_timer fb_sys_fops syscopyarea sysfillrect
>> snd
>> mei sysimgblt soundcore shpchp sch_fq_codel nfsd autofs4
>> Sep 17 13:02:43 localhost kernel: [ 97.342470] CPU: 0 PID: 530 Comm:
>> TestTask Tainted: G O 4.14.71-rt44 #1
>> Sep 17 13:02:43 localhost kernel: [ 97.342472] task: f3347300
>> task.stack: f32ea000
>> Sep 17 13:02:43 localhost kernel: [ 97.342476] EIP:
>> rcu_note_context_switch+0x2a0/0x4d0
>> Sep 17 13:02:43 localhost kernel: [ 97.342478] EFLAGS: 00010002 CPU:
>> 0
>> Sep 17 13:02:43 localhost kernel: [ 97.342480] EAX: 00000001 EBX:
>> 00000000 ECX: 00000001 EDX: 00000000
>> Sep 17 13:02:43 localhost kernel: [ 97.342482] ESI: 00000000 EDI:
>> f3347300 EBP: f32ebeec ESP: f32ebed0
>> Sep 17 13:02:43 localhost kernel: [ 97.342485] DS: 007b ES: 007b FS:
>> 00d8 GS: 00e0 SS: 0068
>> Sep 17 13:02:43 localhost kernel: [ 97.342487] CR0: 80050033 CR2:
>> 06338490 CR3: 332d4000 CR4: 003406d0
>> Sep 17 13:02:43 localhost kernel: [ 97.342489] Call Trace:
>> Sep 17 13:02:43 localhost kernel: [ 97.342501] ?
>> unpin_current_cpu+0x53/0x80
>> Sep 17 13:02:43 localhost kernel: [ 97.342507] __schedule+0x85/0x700
>> Sep 17 13:02:43 localhost kernel: [ 97.342511] ?
>> _raw_spin_unlock_irqrestore+0x17/0x50
>> Sep 17 13:02:43 localhost kernel: [ 97.342514] ?
>> rt_spin_unlock+0x24/0x50
>> Sep 17 13:02:43 localhost kernel: [ 97.342517] schedule+0x41/0xe0
>> Sep 17 13:02:43 localhost kernel: [ 97.342521]
>> hrtimer_wait_for_timer+0x5d/0x90
>> Sep 17 13:02:43 localhost kernel: [ 97.342525] ?
>> wait_woken+0x70/0x70
>> Sep 17 13:02:43 localhost kernel: [ 97.342530]
>> timer_wait_for_callback+0x40/0x50
>> Sep 17 13:02:43 localhost kernel: [ 97.342533]
>> SyS_timer_delete+0x6b/0x140
>> Sep 17 13:02:43 localhost kernel: [ 97.342538]
>> do_int80_syscall_32+0x6b/0xf0
>> Sep 17 13:02:43 localhost kernel: [ 97.342542]
>> entry_INT80_32+0x31/0x31
>> Sep 17 13:02:43 localhost kernel: [ 97.342545] EIP: 0xb22c68d0
>> Sep 17 13:02:43 localhost kernel: [ 97.342546] EFLAGS: 00000282 CPU:
>> 0
>> Sep 17 13:02:43 localhost kernel: [ 97.342548] EAX: ffffffda EBX:
>> 00000002 ECX: 00000000 EDX: b1d00480
>> Sep 17 13:02:43 localhost kernel: [ 97.342550] ESI: b1d005e0 EDI:
>> b22cc000 EBP: b1fc7318 ESP: b1fc72b0
>> Sep 17 13:02:43 localhost kernel: [ 97.342552] DS: 007b ES: 007b FS:
>> 0000 GS: 0033 SS: 007b
>> Sep 17 13:02:43 localhost kernel: [ 97.342556] Code: c3 83 e8 01 39
>> c2 0f 85 27 02 00 00 83 f9 0f 8d 97 f8 02 00 00 0f 87 78 01 00 00 8b 04
>> 8d f8 52 51 c3 e9 a4 9b 83 00 8d 74 26 00 <0f> 0b 80
>> bf f4 02 00 00 00 0f 85 a6 fd ff ff e9 1c ff ff ff 8d
>> Sep 17 13:02:43 localhost kernel: [ 97.342600] ---[ end trace
>> 0000000000000002 ]---
>> The issue can be reproduced with the following simple program
>> ///////////////////////////////////////////////////////////////////////
>> ////////
>> // Test application
>> ///////////////////////////////////////////////////////////////////////
>> ////////
>> #include <stdio.h>
>> #include <unistd.h> // usleep
>> #include <alchemy/task.h>
>> #define CPU_AFFINITY_DEFAULT 0
>> #define MAIN_TASK_NAME "MainTask"
>> #define MAIN_TASK_PRIO 0
>> #define MAIN_TASK_MODE 0
>> #define TESTTASK_NAME "TestTask"
>> #define TESTTASK_PRIO 10
>> #define TESTTASK_MODE 0
>> #define TESTTASK_STACKSIZE 0x100000l // 1 MB
>> #define TESTTASK_PERIOD_NS (5* 1000000)
>> typedef struct {
>> RT_TASK TaskDescr;
>> int nEndTask;
>> int Period_ns;
>> } TESTTASK_CONTEXT;
>> RT_TASK g_MainTask;
>> int g_nRun=1;
>> void TestTask(void *pData) {
>> TESTTASK_CONTEXT *pCtx = (TESTTASK_CONTEXT *)pData;
>> unsigned long overrun;
>> int nErr = 0;
>> printf("TestTask starting...\n");
>> nErr = rt_task_set_periodic(NULL, TM_NOW,
>> rt_timer_ns2ticks(pCtx->Period_ns));
>> while (!pCtx->nEndTask) {
>> rt_task_wait_period(&overrun);
>> }
>> printf("TestTask terminating...\n");
>> }
>> int StartTestTask(TESTTASK_CONTEXT* pCtx)
>> {
>> printf("Starting TestTask...\n");
>>
>> int err;
>> pCtx->nEndTask=0;
>> pCtx->Period_ns=TESTTASK_PERIOD_NS;
>> err = rt_task_spawn(&pCtx->TaskDescr, TESTTASK_NAME,
>> TESTTASK_STACKSIZE, TESTTASK_PRIO, T_JOINABLE, TestTask, pCtx);
>> if (err) {
>> printf("Error in rt_task_spawn_() \n");
>> return err;
>> }
>> return 0;
>> }
>> void StopTestTask(TESTTASK_CONTEXT* pCtx){
>> printf("Stopping TestTask...\n");
>> pCtx->nEndTask=1;
>>
>> RT_TASK_INFO ti;
>> if (0 == rt_task_inquire(&pCtx->TaskDescr, &ti) ) {
>> rt_task_join(&pCtx->TaskDescr);
>> }
>> }
>>
>> // Signalhandler für SIGTERM und SIGINT (Ctrl-C)
>> void TerminationHandler(int sig) {
>> if(sig==SIGTERM) {
>> printf("##### Termination Signal Handler(%d) #####\n",sig);
>> }
>> if(sig==SIGINT) {
>> printf("##### Signal Handler(%d) #####\n",sig);
>> }
>> g_nRun=0;
>> return;
>> }
>> int main(int argc, char* argv[]){
>> TESTTASK_CONTEXT ctxTestTask;
>> signal(SIGTERM, TerminationHandler);
>> signal(SIGINT, TerminationHandler);
>> StartTestTask(&ctxTestTask);
>> //--- Main Loop ---
>> while(g_nRun != 0 ) {
>> printf("main loop\n");
>> usleep(1000000); // sleep 1 sec
>> }
>> StopTestTask(&ctxTestTask);
>> printf("MainTask terminating\n");
>> return 0;
>> }
>> ///////////////////////////////////////////////////////////////////////
>> ////////
>> // End: Test application
>> ///////////////////////////////////////////////////////////////////////
>> ////////
>>
>> Any ideas what could be the problem?
>>
>>
>> Thanks in advance
>> Jochen
>>
>
>--
>Siemens AG, Corporate Technology, CT RDA IOT SES-DE
>Corporate Competence Center Embedded Linux
>
--
Siemens AG, Corporate Technology, CT RDA IOT SES-DE
Corporate Competence Center Embedded Linux
