tree 347954128866e68485eaa1ddedbb24029f86f24f
parent 7c470539c95630c1f2a10f109e96f249730b75eb
author Christian Borntraeger <borntraeger@de.ibm.com> 1368794498 +0200
committer Gleb Natapov <gleb@redhat.com> 1369126538 +0300

s390: fix gmap_ipte_notifier vs. software dirty pages

On heavy paging load some guest cpus started to loop in gmap_ipte_notify.
This was visible as stalled cpus inside the guest. The gmap_ipte_notifier
tries to map a user page and then made sure that the pte is valid and
writable. Turns out that with the software change bit tracking the pte
can become read-only (and only software writable) if the page is clean.
Since we loop in this code, the page would stay clean and, therefore,
be never writable again.
Let us just use fixup_user_fault, that guarantees to call handle_mm_fault.

Signed-off-by: Christian Borntraeger <borntraeger@de.ibm.com>
Acked-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
Signed-off-by: Gleb Natapov <gleb@redhat.com>