On Mon, Oct 17, 2022 at 01:34:13PM +0800, Zhaoyang Huang wrote:
> On Fri, Oct 14, 2022 at 8:12 PM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote:
> >
> > On Fri, Oct 14, 2022 at 01:30:48PM +0800, zhaoyang.huang wrote:
> > > From: Zhaoyang Huang <zhaoyang.huang@xxxxxxxxxx>
> > >
> > > Bellowing RCU stall is reported where kswapd traps in a live lock when shrink
> > > superblock's inode list. The direct reason is zombie page keeps staying on the
> > > xarray's slot and make the check and retry loop permanently. The root cause is unknown yet
> > > and supposed could be an xa update without synchronize_rcu etc. I would like to
> > > suggest skip this page to break the live lock as a workaround.
> >
> > No, the underlying bug should be fixed.
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> OK, could I move the xas like below?
>
> + if (!folio_try_get_rcu(folio)) {
> + xas_next_offset(xas);
> goto reset;
> + }
