Hello, On Wed, Dec 18, 2013 at 11:15:23AM +0800, Vaughan Cao wrote: > I suppose there is a fault in the patch of > https://lkml.org/lkml/2013/1/16/546. > I know you made a new patch for latest kernel which don't move the entry > between pending and running list that remove the code I mentioned, but our > kernel is based on v3.8.13 that has the code. > > In my understanding, both pending and running list are sorted ascendingly by > cookie value. To find the correct postion to insert the entry into running > list, we traverse reversely to the head. When a node with a smaller cookie is > found, we break out and add the new entry after it. But the origin code tries > to find a larger cookie and insert itself before that node, it won't result in > a sorted list in any direction...
Yeah, I should have used list_for_each_entry() there. LOL, I'm an idiot. > I don't know if my understanding about the async mechanism is right, so here > to have a check with you. Thanks. > > Signed-off-by: Vaughan Cao <vaughan....@oracle.com> > --- > kernel/async.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > diff --git a/kernel/async.c b/kernel/async.c > index 6f34904..596c5e7 100644 > --- a/kernel/async.c > +++ b/kernel/async.c > @@ -135,9 +135,9 @@ static void async_run_entry_fn(struct work_struct *work) > /* 1) move self to the running queue, make sure it stays sorted */ > spin_lock_irqsave(&async_lock, flags); > list_for_each_entry_reverse(pos, &running->domain, list) > - if (entry->cookie < pos->cookie) > + if (entry->cookie > pos->cookie) > break; > - list_move_tail(&entry->list, &pos->list); > + list_move(&entry->list, &pos->list); Hmmm... sadly, upstream doesn't have the ability to backport this. The relevant code path is gone and -stable doesn't backport patches which aren't mainline first. The only way would be backporting through distros, I guess. But, again, this problem shouldn't be noticeable with modern userland and it has been broekn without anyone noticing for long enough, so maybe we can just leave it alone? Thanks. -- tejun -- 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/
