On Mon, 15 Sep 2014, Naoya Horiguchi wrote: > When running the test which causes the race as shown in the previous patch, > we can hit the BUG "get_page() on refcount 0 page" in hugetlb_fault().
Two minor comments... > @@ -3192,22 +3208,19 @@ int hugetlb_fault(struct mm_struct *mm, struct > vm_area_struct *vma, > * Note that locking order is always pagecache_page -> page, > * so no worry about deadlock. That sentence of comment is stale and should be deleted, now that you're only doing a trylock_page(page) here. > out_mutex: > mutex_unlock(&htlb_fault_mutex_table[hash]); > + if (need_wait_lock) > + wait_on_page_locked(page); > return ret; > } It will be hard to trigger any problem from this (I guess it would need memory hotremove), but you ought really to hold a reference to page while doing a wait_on_page_locked(page). -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
