On 4/24/21 7:07 PM, Guenter Roeck wrote: > On 4/24/21 8:27 AM, Peter.Enderborg@xxxxxxxx wrote: >> On 4/24/21 4:41 PM, Guenter Roeck wrote: >>> On 4/24/21 3:25 AM, Peter Enderborg wrote: >>>> This is not a rebooting watchdog. It's function is to take other >>>> actions than a hard reboot. On many complex system there is some >>>> kind of manager that monitor and take action on slow systems. >>>> Android has it's lowmemorykiller (lmkd), desktops has earlyoom. >>>> This watchdog can be used to help monitor to preform some basic >>>> action to keep the monitor running. >>>> >>>> It can also be used standalone. This add a policy that is >>>> killing the process with highest oom_score_adj and using >>>> oom functions to it quickly. I think it is a good usecase >>>> for the patch. Memory siuations can be problematic for >>>> software that monitor system, but other prolicys can >>>> should also be possible. Like picking tasks from a memcg, or >>>> specific UID's or what ever is low priority. >>>> --- >>> NACK. Besides this not following the new watchdog API, the task >>> of a watchdog is to reset the system on failure. Its task is most >>> definitely not to re-implement the oom killer in any way, shape, >>> or form. >>> >>> Guenter >> Do you have better idea where the re-invented wheel might >> fit better if it not for watchdog API? >> > The watchdog subsystem does support pretimeouts and a variety > of configurable pretimeout notifiers. A pretimeout notifier which > invokes the oom killer might be something worth discussing, though > it would require an audience large enough to determine if it really > makes sense (instead of improving the existing oom killer itself). > > A possible alternative might be to introduce watchdog pretimeout > callbacks; this has actually be proposed in another context but > without upstream user. The oom killer could then subscribe to > watchdog pretimeouts and perform the action suggested here if > a pretimeout is observed. Again, such an approach might be worth > discussing with a larger audience. > > Thanks, > Guenter What should be a larger audience? I have include mm and mm maintainer and the global list.
