On Fri, Jul 23, 2021 at 09:51:09AM +0800, Miaohe Lin wrote: > On 2021/7/22 22:00, Greg KH wrote: > > 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. > > > > I browsed my previous backport notifying email and found that these two patches are also > backported into 5.12. And it seems it's missed. 5.12 is now end-of-life, it's not being touched anymore, and no one should continue to use it. thanks, greg k-h
