On Mon 15-10-18 19:57:35, Tetsuo Handa wrote: > On 2018/10/15 17:19, Michal Hocko wrote: > > As so many dozens of times before, I will point you to an incremental > > nature of changes we really prefer in the mm land. We are also after a > > simplicity which your proposal lacks in many aspects. You seem to ignore > > that general approach and I have hard time to consider your NAK as a > > relevant feedback. Going to an extreme and basing a complex solution on > > it is not going to fly. No killable process should be a rare event which > > requires a seriously misconfigured memcg to happen so wildly. If you can > > trigger it with a normal user privileges then it would be a clear bug to > > address rather than work around with printk throttling. > > > > I can trigger 200+ times / 900+ lines / 69KB+ of needless OOM messages > with a normal user privileges. This is a lot of needless noise/delay. I am pretty sure you have understood the part of my message you have chosen to not quote where I have said that the specific rate limitting decisions can be changed based on reasonable configurations. There is absolutely zero reason to NAK a natural decision to unify the throttling and cook a per-memcg way for a very specific path instead. > No killable process is not a rare event, even without root privileges. > > [root@ccsecurity kumaneko]# time ./a.out > Killed > > real 0m2.396s > user 0m0.000s > sys 0m2.970s > [root@ccsecurity ~]# dmesg | grep 'no killable' | wc -l > 202 > [root@ccsecurity ~]# dmesg | wc > 942 7335 70716 OK, so this is 70kB worth of data pushed throug the console. Is this really killing any machine? -- Michal Hocko SUSE Labs
