Michal Hocko wrote: > On Tue 27-06-17 20:39:28, Tetsuo Handa wrote: > > Michal Hocko wrote: > > > > I wonder why you prefer timeout based approach. Your patch will after all > > > > set MMF_OOM_SKIP if operations between down_write() and up_write() took > > > > more than one second. > > > > > > if we reach down_write then we have unmapped the address space in > > > exit_mmap and oom reaper cannot do much more. > > > > So, by the time down_write() is called, majority of memory is already released, isn't it? > > In most cases yes. To be put it in other words. By the time exit_mmap > takes down_write there is nothing more oom reaper could reclaim. > Then, aren't there two exceptions which your patch cannot guarantee; down_write(&mm->mmap_sem) in __ksm_exit() and __khugepaged_exit() ? Since for some reason exit_mmap() cannot be brought to before ksm_exit(mm)/khugepaged_exit(mm) calls, ksm_exit(mm); khugepaged_exit(mm); /* must run before exit_mmap */ exit_mmap(mm); shouldn't we try __oom_reap_task_mm() before calling these down_write() if mm is OOM victim's? -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>
