Balbir Singh wrote: > Li Zefan wrote: >> Balbir Singh wrote: >>> YAMAMOTO Takashi wrote: >>>>> Li Zefan wrote: >>>>>> No need for VM_BUG_ON(pc), since 'pc' is the list entry. This should >>>>>> be VM_BUG_ON(page). >>>>>> >>>>>> Signed-off-by: Li Zefan <[EMAIL PROTECTED]> >>>>>> Acked-by: KAMEZAWA Hiroyuki <[EMAIL PROTECTED]> >>>>> pc is of type page_cgroup and we use list_for_each_entry_safe_reverse. >>>>> Not sure >>>>> why we can't bug on pc. >>>> pc is dereferenced before this VM_BUG_ON. >>>> >>>> YAMAMOTO Takashi >>>> >>> OK, so the VM_BUG_ON needs to move to an earlier location. Agreed. >>> >> No, 'pc' has been dereferenced in list_for_each_entry_safe_reverse(). >> >> >> #define list_for_each_entry_safe_reverse(pos, n, head, member) >> \ >> for (pos = list_entry((head)->prev, typeof(*pos), member), \ >> n = list_entry(pos->member.prev, typeof(*pos), member); \ >> ^^^^^^^^^^^ >> &pos->member != (head); \ >> ^^^^^^^^^^^ >> pos = n, n = list_entry(n->member.prev, typeof(*n), member)) >> > > Hmm.. We used to have a for loop with !list_empty() as a termination condition > and VM_BUG_ON(!pc) is a spill over. With the new loop, VM_BUG_ON(!pc) does not > make sense. > >
I see, and I'll post a new patch to just remove it. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
