On Mon, Oct 29, 2012 at 5:41 PM, Avi Kivity <a...@redhat.com> wrote:
> On 10/29/2012 01:48 AM, Liu Ping Fan wrote:
>> Without biglock, we try to protect the mr by increase refcnt.
>> If we can inc refcnt, go backward and resort to biglock.
>>
>> Another point is memory radix-tree can be flushed by another
>> thread, so we should get the copy of terminal mr to survive
>> from such issue.
>>
>
>> +static bool memory_region_section_ref(MemoryRegionSection *mrs)
>> +{
>> + MemoryRegion *mr;
>> + bool ret = false;
>> +
>> + mr = mrs->mr;
>> + if (mr->ops && mr->ops->ref) {
>> + ret = mr->ops->ref(mr);
>
> I still don't see why ->ref() needs to return something.
>
My original design use it to trace refcnt on object, but now it
abandons. Will drop it.
>> + }
>> + return ret;
>> +}
>> +
>>
>> while (len > 0) {
>> page = addr & TARGET_PAGE_MASK;
>> l = (page + TARGET_PAGE_SIZE) - addr;
>> if (l > len)
>> l = len;
>> - section = phys_page_find(d, page >> TARGET_PAGE_BITS);
>> +
>> + if (as->lock) {
>> + qemu_mutex_lock(as->lock);
>> + safe_ref = memory_region_section_lookup_ref(d, page, &obj_mrs);
>> + qemu_mutex_unlock(as->lock);
>> + if (!safe_ref) {
>> + qemu_mutex_lock_iothread();
>> + qemu_mutex_lock(as->lock);
>> + /* when 2nd try, mem map can change, need to judge it again
>> */
>> + safe_ref = memory_region_section_lookup_ref(d, page,
>> &obj_mrs);
>> + qemu_mutex_unlock(as->lock);
>> + if (safe_ref) {
>> + qemu_mutex_unlock_iothread();
>> + }
>> + }
>> + } else {
>> + /* Caller hold the big lock */
>> + memory_region_section_lookup_ref(d, page, &obj_mrs);
>
> It's not a property of the address space, it's a property of the caller.
>
Sorry, what is your meaning?
>> + }
>> + section = &obj_mrs;
>>
>> if (is_write) {
>> if (!memory_region_is_ram(section->mr)) {
>
>
> --
> error compiling committee.c: too many arguments to function
>
