On 2020/8/26 18:21, David Edmondson wrote:
> On Monday, 2020-08-24 at 17:14:38 +08, Chuan Zheng wrote:
>
>> Implement calculate_dirtyrate() function.
>>
>> Signed-off-by: Chuan Zheng <zhengch...@huawei.com>
>> Signed-off-by: YanYing Zhuang <ann.zhuangyany...@huawei.com>
>> ---
>> migration/dirtyrate.c | 45 +++++++++++++++++++++++++++++++++++++++++++--
>> 1 file changed, 43 insertions(+), 2 deletions(-)
>>
>> diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
>> index d1c0a78..9f52f5f 100644
>> --- a/migration/dirtyrate.c
>> +++ b/migration/dirtyrate.c
>> @@ -171,6 +171,21 @@ static void get_ramblock_dirty_info(RAMBlock *block,
>> strcpy(info->idstr, qemu_ram_get_idstr(block));
>> }
>>
>> +static void free_ramblock_dirty_info(struct RamblockDirtyInfo *infos, int
>> count)
>> +{
>> + int i;
>> +
>> + if (!infos) {
>> + return;
>> + }
>> +
>> + for (i = 0; i < count; i++) {
>> + g_free(infos[i].sample_page_vfn);
>> + g_free(infos[i].hash_result);
>> + }
>> + g_free(infos);
>> +}
>> +
>> static struct RamblockDirtyInfo *
>> alloc_ramblock_dirty_info(int *block_index,
>> struct RamblockDirtyInfo *block_dinfo)
>> @@ -316,8 +331,34 @@ static int compare_page_hash_info(struct
>> RamblockDirtyInfo *info,
>>
>> static void calculate_dirtyrate(struct DirtyRateConfig config)
>> {
>> - /* todo */
>> - return;
>> + struct RamblockDirtyInfo *block_dinfo = NULL;
>> + int block_index = 0;
>> + int64_t msec = 0;
>> + int64_t initial_time;
>> +
>> + rcu_register_thread();
>> + reset_dirtyrate_stat();
>> + initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
>> + rcu_read_lock();
>
> Page dirtying that happens while acquiring the lock will not be
> accounted for, but is within the time window. Could we store the time
> after acquiring the lock?
>
Yes, it would be better.
will fix in V6.
>> + if (record_ramblock_hash_info(&block_dinfo, config, &block_index) < 0) {
>> + goto out;
>> + }
>> + rcu_read_unlock();
>> +
>> + msec = config.sample_period_seconds * 1000;
>> + msec = set_sample_page_period(msec, initial_time);
>> +
>> + rcu_read_lock();
>> + if (compare_page_hash_info(block_dinfo, block_index) < 0) {
>> + goto out;
>> + }
>> +
>> + update_dirtyrate(msec);
>> +
>> +out:
>> + rcu_read_unlock();
>
> Is it necessary to hold the lock across update_dirtyrate()?
>
There is no need for that.
Will fix it in V6.
>> + free_ramblock_dirty_info(block_dinfo, block_index + 1);
>> + rcu_unregister_thread();
>> }
>>
>> void *get_dirtyrate_thread(void *arg)
>> --
>> 1.8.3.1
>
> dme.
>
