* Andrea Righi (andrea@xxxxxxxxxxxxxxx) wrote: > mmh.. I can reproduce the bug also with the standard ubuntu (11.04) > kernel. Could you post your .config? Andrea (Righi), can you tell me if this WARN fires? This looks like a pure race between removing from list and checking list, i.e. insufficient locking. ksm_scan.mm_slot == the only registered mm CPU 1 (bug program) CPU 2 (ksmd) list_empty() is false lock ksm_scan.mm_slot list_del unlock slot == &ksm_mm_head (but list is now empty_) diff --git a/mm/ksm.c b/mm/ksm.c index 942dfc7..ab79a92 100644 --- a/mm/ksm.c +++ b/mm/ksm.c @@ -1301,6 +1301,7 @@ static struct rmap_item *scan_get_next_rmap_item(struct page **page) slot = list_entry(slot->mm_list.next, struct mm_slot, mm_list); ksm_scan.mm_slot = slot; spin_unlock(&ksm_mmlist_lock); + WARN_ON(slot == &ksm_mm_head); next_mm: ksm_scan.address = 0; ksm_scan.rmap_list = &slot->rmap_list; -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>