On 4/24/21 5:23 PM, Tetsuo Handa wrote: > On 2021/04/24 23:41, 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. >> > I don't think this proposal is a watchdog. I think this proposal is > a timer based process killer, based on an assumption that any slowdown > which prevents the monitor process from pinging for more than 0.5 seconds > (if HZ == 1000) is caused by memory pressure. You missing the point. The oom killer is a example of a work that it can do. it is one policy. The idea is that you should have a policy that fits your needs. oom_score_adj is suitable for a android world. But it might be based on uid's if your priority is some users over other. Or a memcg. Or as Christophe Leroy want the current. The policy is only a example that fits a one area. You need to describe your prioritization, in android it is oom_score_adj. For example I would very much have a policy that sends sigterm instead of sigkill. But the integration with oom is there because it is needed. Maybe a bad choice for political reasons but I don't it a good idea to hide the intention. Please don't focus on the oom part.
