On Thu, Jun 20, 2019 at 6:03 PM Tetsuo Handa <penguin-ker...@i-love.sakura.ne.jp> wrote: > > On 2019/06/20 14:55, Yafang Shao wrote: > > When sys_hung_task_warnings reaches 0, the hang task messages will not > > be reported any more. > > It is a common mistake that sys_hung_task_warnings is already 0 when > a real problem which should be reported occurred. > > > > > If the user want to get more hung task messages, he must reset > > kernel.hung_task_warnings to a postive integer or -1 with sysctl. > > People are setting sys_hung_task_warnings to -1 in order to make sure > that the messages are printed. > > > This is not a good way for the user. > > But I don't think we should reset automatically. > > > We'd better reset hung task warnings in the kernel, and then the user > > don't need to pay attention to this value. > > I suggest changing the default value of sys_hung_task_warnings to -1. >
Yes, that's what we have did now. > > > > With this patch, hung task warnings will be reset with > > sys_hung_task_warnings setting in evenry check interval. > > Since it is uncommon that the messages are printed for more than 10 > times for one check_hung_uninterruptible_tasks() call, this patch is > effectively changing to always print the messages (in other words, > setting -1). If sys_hung_task_warnings can't be recovered, does it make sense to exist? In which case do we need this setting ? Btw, why the default value of this setting is 10, instead of -1 ? Thanks Yafang
