sagig@xxxxxxxxxxxx wrote:
Now that anon_vma lock and i_mmap_mutex are both sleepable mutex, it is possible to schedule inside invalidation callbacks
(such as invalidate_page, invalidate_range_start/end and change_pte) .
This is essential for a scheduling HW sync in RDMA drivers which apply on demand paging methods.
Signed-off-by: sagi grimberg<sagig@xxxxxxxxxxxxxx>
Ok, this is better, but it still does not work =)
Nobody synchronize with this srcu. There at least two candidates:
mmu_notifier_release() and mmu_notifier_unregister().
They call synchronize_rcu(), you must replace it with synchronize_srcu().
---
changes from V0:
1. srcu_struct should be shared and not allocated in each callback - removed from callbacks
2. added srcu_struct under mmu_notifier_mm
3. init_srcu_struct when creating mmu_notifier_mm
4. srcu_cleanup when destroying mmu_notifier_mm
@@ -204,6 +208,8 @@ static int do_mmu_notifier_register(struct mmu_notifier *mn,
if (!mm_has_notifiers(mm)) {
INIT_HLIST_HEAD(&mmu_notifier_mm->list);
+ if (init_srcu_struct(&mmu_notifier_mm->srcu))
+ goto out_cleanup;
move it upper, out of mm->mmap_sem lock. and fix error path.
spin_lock_init(&mmu_notifier_mm->lock);
mm->mmu_notifier_mm = mmu_notifier_mm;
mmu_notifier_mm = NULL;
@@ -266,6 +272,7 @@ EXPORT_SYMBOL_GPL(__mmu_notifier_register);
void __mmu_notifier_mm_destroy(struct mm_struct *mm)
{
BUG_ON(!hlist_empty(&mm->mmu_notifier_mm->list));
+ cleanup_srcu_struct(&mm->mmu_notifier_mm->srcu);
kfree(mm->mmu_notifier_mm);
mm->mmu_notifier_mm = LIST_POISON1; /* debug */
}
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>