Re: INFO: rcu detected stall in shmem_fault

[Sergey Senozhatsky]

On (10/10/18 22:10), Tetsuo Handa wrote:
> >> I've found at least 1 place that uses DEFAULT_RATELIMIT_INTERVAL*10:
> >> https://elixir.bootlin.com/linux/latest/source/fs/btrfs/extent-tree.c#L8365
> >> Probably we need something similar here.
> 
> Since printk() is a significantly CPU consuming operation, I think that what
> we need to guarantee is interval between the end of an OOM killer messages
> and the beginning of next OOM killer messages is large enough. For example,
> setup a timer with 5 seconds timeout upon the end of an OOM killer messages
> and check whether the timer already fired upon the beginning of next OOM killer
> messages.

Hmm, there is no way to make sure that previous OOM report made it to
consoles. So maybe timer approach will be as good as rate-limiting.

	-ss