On Wed 26-08-20 18:41:18, xunlei wrote: > On 2020/8/26 下午4:11, Michal Hocko wrote: > > On Wed 26-08-20 15:27:02, Xunlei Pang wrote: > >> We've met softlockup with "CONFIG_PREEMPT_NONE=y", when > >> the target memcg doesn't have any reclaimable memory. > > > > Do you have any scenario when this happens or is this some sort of a > > test case? > > It can happen on tiny guest scenarios.
OK, you made me more curious. If this is a tiny guest and this is a hard limit reclaim path then we should trigger an oom killer which should kill the offender and that in turn bail out from the try_charge lopp (see should_force_charge). So how come this repeats enough in your setup that it causes soft lockups? -- Michal Hocko SUSE Labs
