diff mbox series

[v5,03/14] migration: Simplify migration_iteration_run()

Message ID 20221229110345.12480-4-avihaih@nvidia.com
State New
Headers show
Series vfio/migration: Implement VFIO migration protocol v2 | expand

Commit Message

Avihai Horon Dec. 29, 2022, 11:03 a.m. UTC 
From: Juan Quintela <quintela@redhat.com>

Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Avihai Horon <avihaih@nvidia.com>
---
 migration/migration.c | 25 +++++++++++++------------
 1 file changed, 13 insertions(+), 12 deletions(-)

Comments

Alex Williamson Jan. 6, 2023, 5:56 p.m. UTC | #1 
On Thu, 29 Dec 2022 13:03:34 +0200
Avihai Horon <avihaih@nvidia.com> wrote:

> From: Juan Quintela <quintela@redhat.com>

IMHO, there should always be a commit log description.  Why is this a
simplification?  What does it allow us to do?  Nothing later obviously
depends on this, why is it part of this series?  Thanks,

Alex

> Signed-off-by: Juan Quintela <quintela@redhat.com>
> Signed-off-by: Avihai Horon <avihaih@nvidia.com>
> ---
>  migration/migration.c | 25 +++++++++++++------------
>  1 file changed, 13 insertions(+), 12 deletions(-)
> 
> diff --git a/migration/migration.c b/migration/migration.c
> index 9795d0ec5c..61b9ce0fe8 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -3758,23 +3758,24 @@ static MigIterateState migration_iteration_run(MigrationState *s)
>      trace_migrate_pending(pending_size, s->threshold_size,
>                            pend_pre, pend_compat, pend_post);
>  
> -    if (pending_size && pending_size >= s->threshold_size) {
> -        /* Still a significant amount to transfer */
> -        if (!in_postcopy && pend_pre <= s->threshold_size &&
> -            qatomic_read(&s->start_postcopy)) {
> -            if (postcopy_start(s)) {
> -                error_report("%s: postcopy failed to start", __func__);
> -            }
> -            return MIG_ITERATE_SKIP;
> -        }
> -        /* Just another iteration step */
> -        qemu_savevm_state_iterate(s->to_dst_file, in_postcopy);
> -    } else {
> +
> +    if (!pending_size || pending_size < s->threshold_size) {
>          trace_migration_thread_low_pending(pending_size);
>          migration_completion(s);
>          return MIG_ITERATE_BREAK;
>      }
>  
> +    /* Still a significant amount to transfer */
> +    if (!in_postcopy && pend_pre <= s->threshold_size &&
> +        qatomic_read(&s->start_postcopy)) {
> +        if (postcopy_start(s)) {
> +            error_report("%s: postcopy failed to start", __func__);
> +        }
> +        return MIG_ITERATE_SKIP;
> +    }
> +
> +    /* Just another iteration step */
> +    qemu_savevm_state_iterate(s->to_dst_file, in_postcopy);
>      return MIG_ITERATE_RESUME;
>  }
>
Avihai Horon Jan. 8, 2023, 4:30 p.m. UTC | #2 
On 06/01/2023 19:56, Alex Williamson wrote:
> External email: Use caution opening links or attachments
>
>
> On Thu, 29 Dec 2022 13:03:34 +0200
> Avihai Horon <avihaih@nvidia.com> wrote:
>
>> From: Juan Quintela <quintela@redhat.com>
> IMHO, there should always be a commit log description.  Why is this a
> simplification?

Yes. It just rephrases the condition so we can drop the else {}.

>    What does it allow us to do?  Nothing later obviously
> depends on this, why is it part of this series?

Right.
This is part of Juan's RFC [1].
Eventually we didn't need the RFC because of the new MIG_DATA_SIZE ioctl.
Since Juan already did this work, I thought I might as well take some of 
these patches.

I will simply drop it in next version.
If a real need to simplify this if else condition arises in the future, 
it can be done then.

Thanks.

[1] 
https://lore.kernel.org/qemu-devel/20221003031600.20084-1-quintela@redhat.com/

>    Thanks,
>
> Alex
>
>> Signed-off-by: Juan Quintela <quintela@redhat.com>
>> Signed-off-by: Avihai Horon <avihaih@nvidia.com>
>> ---
>>   migration/migration.c | 25 +++++++++++++------------
>>   1 file changed, 13 insertions(+), 12 deletions(-)
>>
>> diff --git a/migration/migration.c b/migration/migration.c
>> index 9795d0ec5c..61b9ce0fe8 100644
>> --- a/migration/migration.c
>> +++ b/migration/migration.c
>> @@ -3758,23 +3758,24 @@ static MigIterateState migration_iteration_run(MigrationState *s)
>>       trace_migrate_pending(pending_size, s->threshold_size,
>>                             pend_pre, pend_compat, pend_post);
>>
>> -    if (pending_size && pending_size >= s->threshold_size) {
>> -        /* Still a significant amount to transfer */
>> -        if (!in_postcopy && pend_pre <= s->threshold_size &&
>> -            qatomic_read(&s->start_postcopy)) {
>> -            if (postcopy_start(s)) {
>> -                error_report("%s: postcopy failed to start", __func__);
>> -            }
>> -            return MIG_ITERATE_SKIP;
>> -        }
>> -        /* Just another iteration step */
>> -        qemu_savevm_state_iterate(s->to_dst_file, in_postcopy);
>> -    } else {
>> +
>> +    if (!pending_size || pending_size < s->threshold_size) {
>>           trace_migration_thread_low_pending(pending_size);
>>           migration_completion(s);
>>           return MIG_ITERATE_BREAK;
>>       }
>>
>> +    /* Still a significant amount to transfer */
>> +    if (!in_postcopy && pend_pre <= s->threshold_size &&
>> +        qatomic_read(&s->start_postcopy)) {
>> +        if (postcopy_start(s)) {
>> +            error_report("%s: postcopy failed to start", __func__);
>> +        }
>> +        return MIG_ITERATE_SKIP;
>> +    }
>> +
>> +    /* Just another iteration step */
>> +    qemu_savevm_state_iterate(s->to_dst_file, in_postcopy);
>>       return MIG_ITERATE_RESUME;
>>   }
>>
Cédric Le Goater Jan. 9, 2023, 10:24 a.m. UTC | #3 
On 12/29/22 12:03, Avihai Horon wrote:
> From: Juan Quintela <quintela@redhat.com>
> 
> Signed-off-by: Juan Quintela <quintela@redhat.com>
> Signed-off-by: Avihai Horon <avihaih@nvidia.com>



Reviewed-by: Cédric Le Goater <clg@redhat.com>

Thanks,

C.



> ---
>   migration/migration.c | 25 +++++++++++++------------
>   1 file changed, 13 insertions(+), 12 deletions(-)
> 
> diff --git a/migration/migration.c b/migration/migration.c
> index 9795d0ec5c..61b9ce0fe8 100644
> --- a/migration/migration.c
> +++ b/migration/migration.c
> @@ -3758,23 +3758,24 @@ static MigIterateState migration_iteration_run(MigrationState *s)
>       trace_migrate_pending(pending_size, s->threshold_size,
>                             pend_pre, pend_compat, pend_post);
>   
> -    if (pending_size && pending_size >= s->threshold_size) {
> -        /* Still a significant amount to transfer */
> -        if (!in_postcopy && pend_pre <= s->threshold_size &&
> -            qatomic_read(&s->start_postcopy)) {
> -            if (postcopy_start(s)) {
> -                error_report("%s: postcopy failed to start", __func__);
> -            }
> -            return MIG_ITERATE_SKIP;
> -        }
> -        /* Just another iteration step */
> -        qemu_savevm_state_iterate(s->to_dst_file, in_postcopy);
> -    } else {
> +
> +    if (!pending_size || pending_size < s->threshold_size) {
>           trace_migration_thread_low_pending(pending_size);
>           migration_completion(s);
>           return MIG_ITERATE_BREAK;
>       }
>   
> +    /* Still a significant amount to transfer */
> +    if (!in_postcopy && pend_pre <= s->threshold_size &&
> +        qatomic_read(&s->start_postcopy)) {
> +        if (postcopy_start(s)) {
> +            error_report("%s: postcopy failed to start", __func__);
> +        }
> +        return MIG_ITERATE_SKIP;
> +    }
> +
> +    /* Just another iteration step */
> +    qemu_savevm_state_iterate(s->to_dst_file, in_postcopy);
>       return MIG_ITERATE_RESUME;
>   }
>
diff mbox series

Patch

diff --git a/migration/migration.c b/migration/migration.c
index 9795d0ec5c..61b9ce0fe8 100644
--- a/migration/migration.c
+++ b/migration/migration.c
@@ -3758,23 +3758,24 @@  static MigIterateState migration_iteration_run(MigrationState *s)
     trace_migrate_pending(pending_size, s->threshold_size,
                           pend_pre, pend_compat, pend_post);
 
-    if (pending_size && pending_size >= s->threshold_size) {
-        /* Still a significant amount to transfer */
-        if (!in_postcopy && pend_pre <= s->threshold_size &&
-            qatomic_read(&s->start_postcopy)) {
-            if (postcopy_start(s)) {
-                error_report("%s: postcopy failed to start", __func__);
-            }
-            return MIG_ITERATE_SKIP;
-        }
-        /* Just another iteration step */
-        qemu_savevm_state_iterate(s->to_dst_file, in_postcopy);
-    } else {
+
+    if (!pending_size || pending_size < s->threshold_size) {
         trace_migration_thread_low_pending(pending_size);
         migration_completion(s);
         return MIG_ITERATE_BREAK;
     }
 
+    /* Still a significant amount to transfer */
+    if (!in_postcopy && pend_pre <= s->threshold_size &&
+        qatomic_read(&s->start_postcopy)) {
+        if (postcopy_start(s)) {
+            error_report("%s: postcopy failed to start", __func__);
+        }
+        return MIG_ITERATE_SKIP;
+    }
+
+    /* Just another iteration step */
+    qemu_savevm_state_iterate(s->to_dst_file, in_postcopy);
     return MIG_ITERATE_RESUME;
 }