Re: [Qemu-devel] [PATCH] ram: Split dirty bitmap by RAMBlock

[Juan Quintela <quintela@redhat.com>]

Hailiang Zhang <zhang.zhanghailiang@huawei.com> wrote:
> On 2017/4/25 18:11, Juan Quintela wrote:
>> Both the ram bitmap and the unsent bitmap are split by RAMBlock.
>>
>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>> ---
>>   include/exec/ram_addr.h          |  13 +-
>>   include/migration/postcopy-ram.h |   3 -
>>   migration/postcopy-ram.c         |   5 +-
>>   migration/ram.c                  | 257 +++++++++++++++------------------------
>>   4 files changed, 109 insertions(+), 169 deletions(-)
>>

>> +
>> +    QLIST_FOREACH_RCU(block, &ram_list.blocks, next) {
> ... ...
>> +        unsigned long pages = block->used_length >> TARGET_PAGE_BITS;
>> +        unsigned long *bitmap = block->bmap;
>> +        unsigned long *unsentmap = block->unsentmap;
>> +
>> +        if (!unsentmap) {
>> +            /* We don't have a safe way to resize the sentmap, so
>> +             * if the bitmap was resized it will be NULL at this
>> +             * point.
>> +             */
>> +            error_report("migration ram resized during precopy phase");
>> +            rcu_read_unlock();
>> +            return -EINVAL;
>> +        }
>> +        /* Deal with TPS != HPS and huge pages */
>> +        ret = postcopy_chunk_hostpages(ms, block);
>> +        if (ret) {
>> +            rcu_read_unlock();
>> +            return ret;
>> +        }
>> +
>> +        /*
>> +         * Update the unsentmap to be unsentmap = unsentmap | dirty
>>            */
>> -        error_report("migration ram resized during precopy phase");
>> -        rcu_read_unlock();
>> -        return -EINVAL;
>> +        bitmap_or(unsentmap, unsentmap, bitmap, pages);
>>       }
>> -
>> -    /* Deal with TPS != HPS and huge pages */
>> -    ret = postcopy_chunk_hostpages(ms);
>> -    if (ret) {
>> -        rcu_read_unlock();
>> -        return ret;
>> -    }
>> -
>> -    /*
>> -     * Update the unsentmap to be unsentmap = unsentmap | dirty
>> -     */
>> -    bitmap = atomic_rcu_read(&rs->ram_bitmap)->bmap;
>> -    bitmap_or(unsentmap, unsentmap, bitmap, last_ram_page());
>> -
>> -
>>       trace_ram_postcopy_send_discard_bitmap();
>>   #ifdef DEBUG_POSTCOPY
>>       ram_debug_dump_bitmap(unsentmap, true);
>             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
> It seems that, you forgot to put the above codes in the loop:
>
>   QLIST_FOREACH_RCU(block, &ram_list.blocks, next)
>
> If DEBUG_POSTCOPY is defined, compiling will fail ...

Fixed, thanks.

Now I put that code inside the FOREACH with the "pages" parameter.

Later, Juan.