This commit adds shake_page() for mlocked pages to make sure that the
target
page is flushed out from LRU cache. Without this shake_page(),
subsequent
delete_from_lru_cache() (from me_pagecache_clean()) fails to isolate
it and
the page will finally return back to LRU list. So this scenario leads
to
"hwpoisoned by still linked to LRU list" page.
OK, I see. So does that mean that the LRU handling is no longer needed
and there is a guanratee that all kernels with the above commit cannot
ever get an LRU page?
For the sake of completeness:
I made a quick test reverting 286c469a988 on upstream kernel.
As expected, the poisoned page is in LRU when it hits do_migrate_range,
and so, the migration path is taken and I see the exact failure I saw
on. 4.4
Oscar Salvador
---
Suse L3
