On Wed 22-06-16 23:05:24, zhong jiang wrote: > Hi Aneesh > > CPU0 CPU1 > shrink_page_list() > add_to_swap() > split_huge_page_to_list() > __split_huge_pmd_locked() > pmdp_huge_clear_flush_notify() > // pmd_none() == true > exit_mmap() > unmap_vmas() > zap_pmd_range() > // no action on pmd since pmd_none() == true > pmd_populate() > > > the mm should be the last user when CPU1 process is exiting, CPU0 must be a own mm . > two different process should not be influenced each other. in a words , they should not > have race. No this is a different scenario than http://lkml.kernel.org/r/1466517956-13875-1-git-send-email-zhongjiang@xxxxxxxxxx we were discussing recently. Note that pages are still on the LRU lists while the mm which maps them is exiting. So the above race is very much possible. -- Michal Hocko SUSE Labs -- 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>