On 2022/5/24 14:44, HORIGUCHI NAOYA(堀口 直也) wrote: > On Mon, May 23, 2022 at 07:23:53PM +0800, Miaohe Lin wrote: > ... >>> >>> I reproduced the deadloop issues when swapin error occurs at swapoff time in my linux-next-next-20220520 env, >>> and I found this patch could solve the issue now with the fix in my another email. >>> >>> BTW: When I use dm-dust to inject the swapin IO error, I don't see non-uptodate folio when shmem_swapin_folio >>> and swapoff succeeds. There might be some issues around that module (so I resort to the another way to inject >>> the swapin error), but the patch itself works anyway. ;) >> >> Sorry, the reason I don't see non-uptodate folio when shmem_swapin_folio is that all the shmem pages are still >> in the swapcache. They're not read from disk so there is no really IO error. :) When they're indeed freed, the >> deadloop issue occurs. >> >> I am thinking about extending the function of MADV_PAGEOUT to free the swapcache page. The page resides in the >> swapcache does not save the system memory anyway. And this could help test the swapin behavior. But I'm not >> sure whether it's needed. > > The extension make MADV_PAGEOUT free swapcaches makes sense to me, > so I'll support it if the original implementer agrees the change. I'd like trying to do it when I have time. :) Thanks! > > Thanks, > Naoya Horiguchi >
