On Tue, Oct 18, 2022 at 10:52:19AM +0800, Zhaoyang Huang wrote: > On Mon, Oct 17, 2022 at 11:55 PM Matthew Wilcox <willy@xxxxxxxxxxxxx> wrote: > > > > 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. > > > > ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ > Understand. IMHO, find_get_entry actruely works as an open API dealing > with different kinds of address_spaces page cache, which requires high > robustness to deal with any corner cases. Take the current problem as > example, the inode with fault page(refcount=0) could remain on the > sb's list without live lock problem. But it's a corner case that shouldn't happen! What else is going on at the time? Can you reproduce this problem easily? If so, how?
