Hi
In our custom board with Linux kernel 4.9.123 with Imx6Q processor, we are getting rcu_preempt error and cpu hangs,
The HW doesnt have HDMI or any on screen dispay, however the device had configurations and device tree for, GPU and HDMI enabled.
In the process of debugging the RCU_preempt issue , I disabled the no used peripherals + HDMI and GPU, after disabling I am not seeing the RCU_preempt issue.
Can you provide information why disabling GPU/HDMI solved the issue. or is it a temporary ?
Thanks and Regards
Terry
2021-11-14T04:51:57Z xi-1B-D8-3E user.warn kernel: [973262.472947] hrtimer: interrupt took 195333 ns
2021-11-15T09:46:22Z xi-1B-D8-3E user.err kernel: [1077327.413664] INFO: rcu_preempt detected stalls on CPUs/tasks:
2021-11-15T09:46:22Z xi-1B-D8-3E user.err kernel: [1077327.419542] 1-...: (3 GPs behind) idle=ec7/140000000000000/0 softirq=76321963/76321963 fqs=998
2021-11-15T09:46:22Z xi-1B-D8-3E user.err kernel: [1077327.428506] (detected by 2, t=2103 jiffies, g=36160027, c=36160026, q=40267)
2021-11-15T09:46:22Z xi-1B-D8-3E user.info kernel: [1077327.435836] Task dump for CPU 1:
2021-11-15T09:46:22Z xi-1B-D8-3E user.info kernel: [1077327.439241] swapper/1 R running task 0 0 1 0x00000002
2021-11-15T09:46:22Z xi-1B-D8-3E user.warn kernel: [1077327.446528] [<8089b5b4>] (__schedule) from [<0003d3cd>] (0x3d3cd)
2021-11-15T09:47:25Z xi-1B-D8-3E user.err kernel: [1077390.463664] INFO: rcu_preempt detected stalls on CPUs/tasks:
2021-11-15T09:47:25Z xi-1B-D8-3E user.err kernel: [1077390.469541] 1-...: (3 GPs behind) idle=ec7/140000000000000/0 softirq=76321963/76321963 fqs=3979
2021-11-15T09:47:25Z xi-1B-D8-3E user.err kernel: [1077390.478591] (detected by 2, t=8408 jiffies, g=36160027, c=36160026, q=160474)
2021-11-15T09:47:25Z xi-1B-D8-3E user.info kernel: [1077390.486007] Task dump for CPU 1:
2021-11-15T09:47:25Z xi-1B-D8-3E user.info kernel: [1077390.489414] swapper/1 R running task 0 0 1 0x00000002
2021-11-15T09:47:25Z xi-1B-D8-3E user.warn kernel: [1077390.496702] [<8089b5b4>] (__schedule) from [<0003d3cd>] (0x3d3cd)
2021-11-15T09:48:28Z xi-1B-D8-3E user.err kernel: [1077453.513663] INFO: rcu_preempt detected stalls on CPUs/tasks:
2021-11-15T09:48:28Z xi-1B-D8-3E user.err kernel: [1077453.519541] 1-...: (3 GPs behind) idle=ec7/140000000000000/0 softirq=76321963/76321963 fqs=6972
Hi ,
Can someone help with an information of the above issue.
Thanks and regards
Terry
hello terry,
I've been pleading here for months.People here are so cold, they never talk to anyone.So let it go