On 2021/7/23 15:02, Greg KH wrote: > 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, I see! Many thanks for your kindly explanation! :) > > greg k-h > . >
