Should I do anything about this warning?
Hi, I am new at kernel programming. I have written a driver for a custom device, running on arm board. It works well (for last few months). I happen to look at kernel logs and I seen, [231250.894334] [ cut here ] [231250.899146] WARNING: at kernel/workqueue.c:1953 process_one_work+0x398/0x52c() [231250.906491] Modules linked in: bcmdhd cfg80211 XYZ [231250.911885] [c0016450] (unwind_backtrace+0x0/0x144) from [c05c04f0] (dump_stack+0x20/0x24) [231250.920672] [c05c04f0] (dump_stack+0x20/0x24) from [c006c330] (warn_slowpath_common+0x5c/0x74) [231250.929757] [c006c330] (warn_slowpath_common+0x5c/0x74) from [c006c374] (warn_slowpath_null+0x2c/0x34) [231250.939581] [c006c374] (warn_slowpath_null+0x2c/0x34) from [c0088f08] (process_one_work+0x398/0x52c) [231250.949232] [c0088f08] (process_one_work+0x398/0x52c) from [c00895c8] (rescuer_thread+0x184/0x230) [231250.958708] [c00895c8] (rescuer_thread+0x184/0x230) from [c008dd60] (kthread+0xac/0xb4) [231250.967236] [c008dd60] (kthread+0xac/0xb4) from [c000fd4c] (kernel_thread_exit+0x0/0x8) [231250.975755] ---[ end trace 9f9c2187c0bee21b ]--- The device is still working after this. No issues in operation. I am just sceptical about analyzing this issue? Do I need to check more? If yes how? with this trace? Thanks, Sagar ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Should I do anything about this warning?
On 2014-10-08 12:43:58 (+0530), Sagar Padhye sgr.m@gmail.com wrote: I am new at kernel programming. I have written a driver for a custom device, running on arm board. It works well (for last few months). I happen to look at kernel logs and I seen, [231250.899146] WARNING: at kernel/workqueue.c:1953 process_one_work+0x398/0x52c() You triggered a warning in the code. The device is still working after this. No issues in operation. I am just sceptical about analyzing this issue? Do I need to check more? If yes how? with this trace? Yes, this indicates a potential problem. You start my looking at line 1953 in kernel/workqueue.c, where you'll see which specific warning you're triggering. It's probably this one: /* ensure we're on the correct CPU */ WARN_ON_ONCE(!(pool-flags POOL_DISASSOCIATED) raw_smp_processor_id() != pool-cpu); Regards, Kristof ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
Re: Should I do anything about this warning?
On Wed, Oct 08, 2014 at 11:33:57AM +0200, Kristof Provost wrote: On 2014-10-08 12:43:58 (+0530), Sagar Padhye sgr.m@gmail.com wrote: I am new at kernel programming. I have written a driver for a custom device, running on arm board. It works well (for last few months). I happen to look at kernel logs and I seen, [231250.899146] WARNING: at kernel/workqueue.c:1953 process_one_work+0x398/0x52c() You triggered a warning in the code. Yes, I got that The device is still working after this. No issues in operation. I am just sceptical about analyzing this issue? Do I need to check more? If yes how? with this trace? Yes, this indicates a potential problem. The issue is not reproducible. Haven't seen in over 6 months. And the module is working just fine after the log. Is there a way I can get more info on this e.g. more stacktrace that will end up in module's work function (if this occurs again)? You start my looking at line 1953 in kernel/workqueue.c, where you'll see which specific warning you're triggering. It's probably this one: /* ensure we're on the correct CPU */ WARN_ON_ONCE(!(pool-flags POOL_DISASSOCIATED) raw_smp_processor_id() != pool-cpu); They are, 1952 WARN_ON_ONCE(!(worker-flags (WORKER_UNBOUND | WORKER_REBIND)) 1953 raw_smp_processor_id() != gcwq-cpu); But I am not sure what they signify :( Thanks, Sagar ___ Kernelnewbies mailing list Kernelnewbies@kernelnewbies.org http://lists.kernelnewbies.org/mailman/listinfo/kernelnewbies
