Re: linux-5.13.2: warning from kernel/rcu/tree_plugin.h:359
From: Greg KH
Date: Thu Jul 22 2021 - 10:00:29 EST
On Thu, Jul 22, 2021 at 03:26:52PM +0200, Greg KH wrote:
> On Thu, Jul 22, 2021 at 01:36:02PM +0100, Matthew Wilcox wrote:
> > On Thu, Jul 22, 2021 at 04:57:57PM +0800, Zhouyi Zhou wrote:
> > > Thanks for reviewing,
> > >
> > > What I have deduced from the dmesg is:
> > > In function do_swap_page,
> > > after invoking
> > > 3385 si = get_swap_device(entry); /* rcu_read_lock */
> > > and before
> > > 3561 out:
> > > 3562 if (si)
> > > 3563 put_swap_device(si);
> > > The thread got scheduled out in
> > > 3454 locked = lock_page_or_retry(page, vma->vm_mm, vmf->flags);
> > >
> > > I am only familiar with Linux RCU subsystem, hope mm people can solve our
> > > confusions.
> > I don't understamd why you're still talking. The problem is understood.
> > You need to revert the unnecessary backport of 2799e77529c2 and
> > 2efa33fc7f6e
> Sorry for the delay, will go do so in a minute...
Both now reverted from 5.10.y and 5.13.y.