On 21/05/15 08:46, Jan Beulich wrote:
On 20.05.15 at 17:54, wrote:
>> @@ -702,6 +729,7 @@ __gnttab_map_grant_ref(
>>
>> cache_flags = (shah->flags & (GTF_PAT | GTF_PWT | GTF_PCD) );
>>
>> +active_entry_release(act);
>> spin_unlock(&rgt->lock);
>
> Just for my understanding:
>>> On 20.05.15 at 17:54, wrote:
> @@ -505,7 +526,7 @@ static int grant_map_exists(const struct domain *ld,
> unsigned long mfn,
> unsigned int *ref_count)
> {
> -const struct active_grant_entry *act;
> +struct active_grant_entry *
Introduce a per-active entry spin lock to protect active entry state
The grant table lock must be locked before acquiring (locking) an
active entry.
This is a step in reducing contention on the grant table lock, but
will only do so once the grant table lock is turned into a read-write
lock.
Based
