diff mbox

[1/2] savevm: split save/find loadvm_handlers entry into two helper functions

Message ID 1485327241-15104-2-git-send-email-zhang.zhanghailiang@huawei.com (mailing list archive)
State New, archived
Headers show

Commit Message

Zhanghailiang Jan. 25, 2017, 6:54 a.m. UTC 
COLO's checkpoint process is based on migration process,
everytime we do checkpoint we will repeat the process of savevm and loadvm.

So we will call qemu_loadvm_section_start_full() repeatedly, It will
add all migration sections information into loadvm_handlers list everytime,
which will lead to memory leak.

To fix it, we split the process of saving and finding section entry into two
helper functions, we will check if section info was exist in loadvm_handlers
list before save it.

This modifications have no side effect for normal migration.

Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/savevm.c | 55 +++++++++++++++++++++++++++++++++++++++---------------
 1 file changed, 40 insertions(+), 15 deletions(-)

Comments

Dr. David Alan Gilbert Jan. 31, 2017, 10:04 a.m. UTC | #1 
* zhanghailiang (zhang.zhanghailiang@huawei.com) wrote:
> COLO's checkpoint process is based on migration process,
> everytime we do checkpoint we will repeat the process of savevm and loadvm.
> 
> So we will call qemu_loadvm_section_start_full() repeatedly, It will
> add all migration sections information into loadvm_handlers list everytime,
> which will lead to memory leak.
> 
> To fix it, we split the process of saving and finding section entry into two
> helper functions, we will check if section info was exist in loadvm_handlers
> list before save it.
> 
> This modifications have no side effect for normal migration.
> 
> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
> ---
>  migration/savevm.c | 55 +++++++++++++++++++++++++++++++++++++++---------------
>  1 file changed, 40 insertions(+), 15 deletions(-)
> 
> diff --git a/migration/savevm.c b/migration/savevm.c
> index f9c06e9..92b3d6c 100644
> --- a/migration/savevm.c
> +++ b/migration/savevm.c
> @@ -1805,6 +1805,37 @@ void loadvm_free_handlers(MigrationIncomingState *mis)
>      }
>  }
>  
> +static LoadStateEntry *loadvm_save_section_entry(MigrationIncomingState *mis,

Can you change that to loadvm_add_section_entry please;  it's a bit
confusing using 'save' in a function name that's part of the 'load' path.

Dave

> +                                                 SaveStateEntry *se,
> +                                                 uint32_t section_id,
> +                                                 uint32_t version_id)
> +{
> +    LoadStateEntry *le;
> +
> +    /* Add entry */
> +    le = g_malloc0(sizeof(*le));
> +
> +    le->se = se;
> +    le->section_id = section_id;
> +    le->version_id = version_id;
> +    QLIST_INSERT_HEAD(&mis->loadvm_handlers, le, entry);
> +    return le;
> +}
> +
> +static LoadStateEntry *loadvm_find_section_entry(MigrationIncomingState *mis,
> +                                                 uint32_t section_id)
> +{
> +    LoadStateEntry *le;
> +
> +    QLIST_FOREACH(le, &mis->loadvm_handlers, entry) {
> +        if (le->section_id == section_id) {
> +            break;
> +        }
> +    }
> +
> +    return le;
> +}
> +
>  static int
>  qemu_loadvm_section_start_full(QEMUFile *f, MigrationIncomingState *mis)
>  {
> @@ -1847,15 +1878,12 @@ qemu_loadvm_section_start_full(QEMUFile *f, MigrationIncomingState *mis)
>          return -EINVAL;
>      }
>  
> -    /* Add entry */
> -    le = g_malloc0(sizeof(*le));
> -
> -    le->se = se;
> -    le->section_id = section_id;
> -    le->version_id = version_id;
> -    QLIST_INSERT_HEAD(&mis->loadvm_handlers, le, entry);
> -
> -    ret = vmstate_load(f, le->se, le->version_id);
> +     /* Check if we have saved this section info before, if not, save it */
> +    le = loadvm_find_section_entry(mis, section_id);
> +    if (!le) {
> +        le = loadvm_save_section_entry(mis, se, section_id, version_id);
> +    }
> +    ret = vmstate_load(f, se, version_id);
>      if (ret < 0) {
>          error_report("error while loading state for instance 0x%x of"
>                       " device '%s'", instance_id, idstr);
> @@ -1878,12 +1906,9 @@ qemu_loadvm_section_part_end(QEMUFile *f, MigrationIncomingState *mis)
>      section_id = qemu_get_be32(f);
>  
>      trace_qemu_loadvm_state_section_partend(section_id);
> -    QLIST_FOREACH(le, &mis->loadvm_handlers, entry) {
> -        if (le->section_id == section_id) {
> -            break;
> -        }
> -    }
> -    if (le == NULL) {
> +
> +    le = loadvm_find_section_entry(mis, section_id);
> +    if (!le) {
>          error_report("Unknown savevm section %d", section_id);
>          return -EINVAL;
>      }
> -- 
> 1.8.3.1
> 
> 
--
Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
Zhanghailiang Feb. 6, 2017, 7:13 a.m. UTC | #2 
On 2017/1/31 18:04, Dr. David Alan Gilbert wrote:
> * zhanghailiang (zhang.zhanghailiang@huawei.com) wrote:
>> COLO's checkpoint process is based on migration process,
>> everytime we do checkpoint we will repeat the process of savevm and loadvm.
>>
>> So we will call qemu_loadvm_section_start_full() repeatedly, It will
>> add all migration sections information into loadvm_handlers list everytime,
>> which will lead to memory leak.
>>
>> To fix it, we split the process of saving and finding section entry into two
>> helper functions, we will check if section info was exist in loadvm_handlers
>> list before save it.
>>
>> This modifications have no side effect for normal migration.
>>
>> Signed-off-by: zhanghailiang <zhang.zhanghailiang@huawei.com>
>> Reviewed-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
>> ---
>>   migration/savevm.c | 55 +++++++++++++++++++++++++++++++++++++++---------------
>>   1 file changed, 40 insertions(+), 15 deletions(-)
>>
>> diff --git a/migration/savevm.c b/migration/savevm.c
>> index f9c06e9..92b3d6c 100644
>> --- a/migration/savevm.c
>> +++ b/migration/savevm.c
>> @@ -1805,6 +1805,37 @@ void loadvm_free_handlers(MigrationIncomingState *mis)
>>       }
>>   }
>>
>> +static LoadStateEntry *loadvm_save_section_entry(MigrationIncomingState *mis,
>
> Can you change that to loadvm_add_section_entry please;  it's a bit
> confusing using 'save' in a function name that's part of the 'load' path.
>

OK, will fix it in next version, thanks.

> Dave
>
>> +                                                 SaveStateEntry *se,
>> +                                                 uint32_t section_id,
>> +                                                 uint32_t version_id)
>> +{
>> +    LoadStateEntry *le;
>> +
>> +    /* Add entry */
>> +    le = g_malloc0(sizeof(*le));
>> +
>> +    le->se = se;
>> +    le->section_id = section_id;
>> +    le->version_id = version_id;
>> +    QLIST_INSERT_HEAD(&mis->loadvm_handlers, le, entry);
>> +    return le;
>> +}
>> +
>> +static LoadStateEntry *loadvm_find_section_entry(MigrationIncomingState *mis,
>> +                                                 uint32_t section_id)
>> +{
>> +    LoadStateEntry *le;
>> +
>> +    QLIST_FOREACH(le, &mis->loadvm_handlers, entry) {
>> +        if (le->section_id == section_id) {
>> +            break;
>> +        }
>> +    }
>> +
>> +    return le;
>> +}
>> +
>>   static int
>>   qemu_loadvm_section_start_full(QEMUFile *f, MigrationIncomingState *mis)
>>   {
>> @@ -1847,15 +1878,12 @@ qemu_loadvm_section_start_full(QEMUFile *f, MigrationIncomingState *mis)
>>           return -EINVAL;
>>       }
>>
>> -    /* Add entry */
>> -    le = g_malloc0(sizeof(*le));
>> -
>> -    le->se = se;
>> -    le->section_id = section_id;
>> -    le->version_id = version_id;
>> -    QLIST_INSERT_HEAD(&mis->loadvm_handlers, le, entry);
>> -
>> -    ret = vmstate_load(f, le->se, le->version_id);
>> +     /* Check if we have saved this section info before, if not, save it */
>> +    le = loadvm_find_section_entry(mis, section_id);
>> +    if (!le) {
>> +        le = loadvm_save_section_entry(mis, se, section_id, version_id);
>> +    }
>> +    ret = vmstate_load(f, se, version_id);
>>       if (ret < 0) {
>>           error_report("error while loading state for instance 0x%x of"
>>                        " device '%s'", instance_id, idstr);
>> @@ -1878,12 +1906,9 @@ qemu_loadvm_section_part_end(QEMUFile *f, MigrationIncomingState *mis)
>>       section_id = qemu_get_be32(f);
>>
>>       trace_qemu_loadvm_state_section_partend(section_id);
>> -    QLIST_FOREACH(le, &mis->loadvm_handlers, entry) {
>> -        if (le->section_id == section_id) {
>> -            break;
>> -        }
>> -    }
>> -    if (le == NULL) {
>> +
>> +    le = loadvm_find_section_entry(mis, section_id);
>> +    if (!le) {
>>           error_report("Unknown savevm section %d", section_id);
>>           return -EINVAL;
>>       }
>> --
>> 1.8.3.1
>>
>>
> --
> Dr. David Alan Gilbert / dgilbert@redhat.com / Manchester, UK
>
> .
>
diff mbox

Patch

diff --git a/migration/savevm.c b/migration/savevm.c
index f9c06e9..92b3d6c 100644
--- a/migration/savevm.c
+++ b/migration/savevm.c
@@ -1805,6 +1805,37 @@  void loadvm_free_handlers(MigrationIncomingState *mis)
     }
 }
 
+static LoadStateEntry *loadvm_save_section_entry(MigrationIncomingState *mis,
+                                                 SaveStateEntry *se,
+                                                 uint32_t section_id,
+                                                 uint32_t version_id)
+{
+    LoadStateEntry *le;
+
+    /* Add entry */
+    le = g_malloc0(sizeof(*le));
+
+    le->se = se;
+    le->section_id = section_id;
+    le->version_id = version_id;
+    QLIST_INSERT_HEAD(&mis->loadvm_handlers, le, entry);
+    return le;
+}
+
+static LoadStateEntry *loadvm_find_section_entry(MigrationIncomingState *mis,
+                                                 uint32_t section_id)
+{
+    LoadStateEntry *le;
+
+    QLIST_FOREACH(le, &mis->loadvm_handlers, entry) {
+        if (le->section_id == section_id) {
+            break;
+        }
+    }
+
+    return le;
+}
+
 static int
 qemu_loadvm_section_start_full(QEMUFile *f, MigrationIncomingState *mis)
 {
@@ -1847,15 +1878,12 @@  qemu_loadvm_section_start_full(QEMUFile *f, MigrationIncomingState *mis)
         return -EINVAL;
     }
 
-    /* Add entry */
-    le = g_malloc0(sizeof(*le));
-
-    le->se = se;
-    le->section_id = section_id;
-    le->version_id = version_id;
-    QLIST_INSERT_HEAD(&mis->loadvm_handlers, le, entry);
-
-    ret = vmstate_load(f, le->se, le->version_id);
+     /* Check if we have saved this section info before, if not, save it */
+    le = loadvm_find_section_entry(mis, section_id);
+    if (!le) {
+        le = loadvm_save_section_entry(mis, se, section_id, version_id);
+    }
+    ret = vmstate_load(f, se, version_id);
     if (ret < 0) {
         error_report("error while loading state for instance 0x%x of"
                      " device '%s'", instance_id, idstr);
@@ -1878,12 +1906,9 @@  qemu_loadvm_section_part_end(QEMUFile *f, MigrationIncomingState *mis)
     section_id = qemu_get_be32(f);
 
     trace_qemu_loadvm_state_section_partend(section_id);
-    QLIST_FOREACH(le, &mis->loadvm_handlers, entry) {
-        if (le->section_id == section_id) {
-            break;
-        }
-    }
-    if (le == NULL) {
+
+    le = loadvm_find_section_entry(mis, section_id);
+    if (!le) {
         error_report("Unknown savevm section %d", section_id);
         return -EINVAL;
     }