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[PATCH v6 10/12] migration/dirtyrate: Implement calculate_dirtyrate() function

Chuan Zheng posted 12 patches 5 years, 5 months ago
Maintainers: Eric Blake <eblake@redhat.com>, Markus Armbruster <armbru@redhat.com>, Juan Quintela <quintela@redhat.com>, "Dr. David Alan Gilbert" <dgilbert@redhat.com>
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[PATCH v6 10/12] migration/dirtyrate: Implement calculate_dirtyrate() function
Posted by Chuan Zheng 5 years, 5 months ago 
Implement calculate_dirtyrate() function.

Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
Signed-off-by: YanYing Zhuang <ann.zhuangyanying@huawei.com>
---
 migration/dirtyrate.c | 45 +++++++++++++++++++++++++++++++++++++++++++--
 1 file changed, 43 insertions(+), 2 deletions(-)

diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
index 850126d..95ee23e 100644
--- a/migration/dirtyrate.c
+++ b/migration/dirtyrate.c
@@ -162,6 +162,21 @@ 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)
@@ -301,8 +316,34 @@ 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();
+    rcu_read_lock();
+    initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
+    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();
+    free_ramblock_dirty_info(block_dinfo, block_index + 1);
+    rcu_unregister_thread();
 }
 
 void *get_dirtyrate_thread(void *arg)
-- 
1.8.3.1
Re: [PATCH v6 10/12] migration/dirtyrate: Implement calculate_dirtyrate() function
Posted by David Edmondson 5 years, 5 months ago 
On Saturday, 2020-08-29 at 10:52:55 +08, Chuan Zheng wrote:

> Implement calculate_dirtyrate() function.
>
> Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
> Signed-off-by: YanYing Zhuang <ann.zhuangyanying@huawei.com>
> ---
>  migration/dirtyrate.c | 45 +++++++++++++++++++++++++++++++++++++++++++--
>  1 file changed, 43 insertions(+), 2 deletions(-)
>
> diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
> index 850126d..95ee23e 100644
> --- a/migration/dirtyrate.c
> +++ b/migration/dirtyrate.c
> @@ -162,6 +162,21 @@ 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)
> @@ -301,8 +316,34 @@ 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();
> +    rcu_read_lock();
> +    initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
> +    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();

This still holds the RCU lock across update_dirtyrate(), which I
understood to be unnecessary.

> +    free_ramblock_dirty_info(block_dinfo, block_index + 1);
> +    rcu_unregister_thread();
>  }
>  
>  void *get_dirtyrate_thread(void *arg)
> -- 
> 1.8.3.1

dme.
-- 
I'd come on over but I haven't got a raincoat.
Re: [PATCH v6 10/12] migration/dirtyrate: Implement calculate_dirtyrate() function
Posted by Zheng Chuan 5 years, 5 months ago 

On 2020/8/31 17:13, David Edmondson wrote:
> On Saturday, 2020-08-29 at 10:52:55 +08, Chuan Zheng wrote:
> 
>> Implement calculate_dirtyrate() function.
>>
>> Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
>> Signed-off-by: YanYing Zhuang <ann.zhuangyanying@huawei.com>
>> ---
>>  migration/dirtyrate.c | 45 +++++++++++++++++++++++++++++++++++++++++++--
>>  1 file changed, 43 insertions(+), 2 deletions(-)
>>
>> diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
>> index 850126d..95ee23e 100644
>> --- a/migration/dirtyrate.c
>> +++ b/migration/dirtyrate.c
>> @@ -162,6 +162,21 @@ 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)
>> @@ -301,8 +316,34 @@ 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();
>> +    rcu_read_lock();
>> +    initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
>> +    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();
> 
> This still holds the RCU lock across update_dirtyrate(), which I
> understood to be unnecessary.
>It does need to update_dirtyrate if we goto out when erro happens.
In order to remove update_dirtyrate out of RCU, it need to add flag
like is_need_update, like:
if (record_ramblock_hash_info(&block_dinfo, config, &block_index) < 0) {
         is_need_update = false;
         goto out;
}

if (is_need_update)
    update_dirtyrate(msec);

I doubt it is worth doing that or it will does any hurt if i holds
the RCU lock across update_dirtyrate()?


>> +    free_ramblock_dirty_info(block_dinfo, block_index + 1);
>> +    rcu_unregister_thread();
>>  }
>>  
>>  void *get_dirtyrate_thread(void *arg)
>> -- 
>> 1.8.3.1
> 
> dme.
>
Re: [PATCH v6 10/12] migration/dirtyrate: Implement calculate_dirtyrate() function
Posted by David Edmondson 5 years, 5 months ago 
On Monday, 2020-08-31 at 19:24:04 +08, Zheng Chuan wrote:

> On 2020/8/31 17:13, David Edmondson wrote:
>> On Saturday, 2020-08-29 at 10:52:55 +08, Chuan Zheng wrote:
>> 
>>> Implement calculate_dirtyrate() function.
>>>
>>> Signed-off-by: Chuan Zheng <zhengchuan@huawei.com>
>>> Signed-off-by: YanYing Zhuang <ann.zhuangyanying@huawei.com>
>>> ---
>>>  migration/dirtyrate.c | 45 +++++++++++++++++++++++++++++++++++++++++++--
>>>  1 file changed, 43 insertions(+), 2 deletions(-)
>>>
>>> diff --git a/migration/dirtyrate.c b/migration/dirtyrate.c
>>> index 850126d..95ee23e 100644
>>> --- a/migration/dirtyrate.c
>>> +++ b/migration/dirtyrate.c
>>> @@ -162,6 +162,21 @@ 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)
>>> @@ -301,8 +316,34 @@ 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();
>>> +    rcu_read_lock();
>>> +    initial_time = qemu_clock_get_ms(QEMU_CLOCK_REALTIME);
>>> +    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();
>> 
>> This still holds the RCU lock across update_dirtyrate(), which I
>> understood to be unnecessary.
>>It does need to update_dirtyrate if we goto out when erro happens.
> In order to remove update_dirtyrate out of RCU, it need to add flag
> like is_need_update, like:
> if (record_ramblock_hash_info(&block_dinfo, config, &block_index) < 0) {
>          is_need_update = false;
>          goto out;
> }
>
> if (is_need_update)
>     update_dirtyrate(msec);
>
> I doubt it is worth doing that or it will does any hurt if i holds
> the RCU lock across update_dirtyrate()?

Honestly I'm not sure if holding the RCU lock a little longer will be
measurable or not, perhaps someone with more experience will have a
better idea.

>
>>> +    free_ramblock_dirty_info(block_dinfo, block_index + 1);
>>> +    rcu_unregister_thread();
>>>  }
>>>  
>>>  void *get_dirtyrate_thread(void *arg)
>>> -- 
>>> 1.8.3.1
>> 
>> dme.
>> 

dme.
-- 
We wanna wait, but here we go again.

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