Re: sched: serial port lockdep warning when offlining CPUs

From	"Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com>
Newsgroups	linux.kernel
Subject	Re: sched: serial port lockdep warning when offlining CPUs
Date	2017-09-28 14:00 +0200
Message-ID	<uuFDX-8w4-9@gated-at.bofh.it> (permalink)
References	<uuDiO-7d1-15@gated-at.bofh.it> <uuDsv-7h4-19@gated-at.bofh.it> <uuEoy-7PA-17@gated-at.bofh.it> <uuFkC-8pL-25@gated-at.bofh.it>
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On Thu, Sep 28, 2017 at 08:36:07PM +0900, Sergey Senozhatsky wrote:
>On (09/28/17 19:30), Sergey Senozhatsky wrote:
>>  lib/ratelimit.c | 3 ++-
>>  1 file changed, 2 insertions(+), 1 deletion(-)
>>
>> diff --git a/lib/ratelimit.c b/lib/ratelimit.c
>> index 08f8043cac61..bddc55834c2e 100644
>> --- a/lib/ratelimit.c
>> +++ b/lib/ratelimit.c
>> @@ -48,7 +48,8 @@ int ___ratelimit(struct ratelimit_state *rs, const char *func)
>>  	if (time_is_before_jiffies(rs->begin + rs->interval)) {
>>  		if (rs->missed) {
>>  			if (!(rs->flags & RATELIMIT_MSG_ON_RELEASE)) {
>> -				pr_warn("%s: %d callbacks suppressed\n", func, rs->missed);
>> +				printk_deferred(KERN_WARN "%s: %d callbacks suppressed\n",
>
>oops...				s/KERN_WARN/KERN_WARNING/
>
>sorry about that.

Okay, that seems to have delt with the callbacks supressed issue.

I also seem to be hitting it as a result of the scheduler triggering a WARN, where print_stack_trace(), for example, just uses printk().

Now I'm not sure what's your approach here, do we keep converting printk to printk_deferred one by one until we whacked every mole?

-- 

Thanks,
Sasha

Thread

sched: serial port lockdep warning when offlining CPUs Sasha Levin <levinsasha928@gmail.com> - 2017-09-28 11:30 +0200
  Re: sched: serial port lockdep warning when offlining CPUs Peter Zijlstra <peterz@infradead.org> - 2017-09-28 11:40 +0200
    Re: sched: serial port lockdep warning when offlining CPUs Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-09-28 12:40 +0200
      Re: sched: serial port lockdep warning when offlining CPUs Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-09-28 13:40 +0200
        Re: sched: serial port lockdep warning when offlining CPUs "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-28 14:00 +0200
          Re: sched: serial port lockdep warning when offlining CPUs Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-09-28 14:00 +0200
          Re: sched: serial port lockdep warning when offlining CPUs Peter Zijlstra <peterz@infradead.org> - 2017-09-28 14:10 +0200
            Re: sched: serial port lockdep warning when offlining CPUs Peter Zijlstra <peterz@infradead.org> - 2017-09-28 14:10 +0200
              Re: sched: serial port lockdep warning when offlining CPUs Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-09-28 14:20 +0200
                Re: sched: serial port lockdep warning when offlining CPUs Peter Zijlstra <peterz@infradead.org> - 2017-09-28 14:30 +0200
      Re: sched: serial port lockdep warning when offlining CPUs Peter Zijlstra <peterz@infradead.org> - 2017-09-28 13:50 +0200
        Re: sched: serial port lockdep warning when offlining CPUs Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-09-28 14:00 +0200
    Re: sched: serial port lockdep warning when offlining CPUs "Levin, Alexander (Sasha Levin)" <alexander.levin@verizon.com> - 2017-09-28 13:10 +0200
      Re: sched: serial port lockdep warning when offlining CPUs Sergey Senozhatsky <sergey.senozhatsky.work@gmail.com> - 2017-09-28 13:20 +0200
        Re: sched: serial port lockdep warning when offlining CPUs Peter Zijlstra <peterz@infradead.org> - 2017-09-28 13:40 +0200

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