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[RFC,11/12] IXGBEVF: Migrate VF statistic data

Message ID 1445445464-5056-12-git-send-email-tianyu.lan@intel.com (mailing list archive)
State New, archived
Headers show

Commit Message

lan,Tianyu Oct. 21, 2015, 4:37 p.m. UTC
VF statistic regs are read-only and can't be migrated via writing back
directly.

Currently, statistic data returned to user space by the driver is not equal
to value of statistic regs. VF driver records value of statistic regs as base data
when net interface is up or open, calculate increased count of regs during
last period of online service and added it to saved_reset data. When user
space collects statistic data, VF driver returns result of
"current - base + saved_reset". "Current" is reg value at that point.

Restoring net function after migration just likes net interface is up or open.
Call existed function to update base and saved_reset data to keep statistic
data continual during migration.

Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
---
 drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c | 3 +++
 1 file changed, 3 insertions(+)

Comments

Michael S. Tsirkin Oct. 22, 2015, 12:36 p.m. UTC | #1
On Thu, Oct 22, 2015 at 12:37:43AM +0800, Lan Tianyu wrote:
> VF statistic regs are read-only and can't be migrated via writing back
> directly.
> 
> Currently, statistic data returned to user space by the driver is not equal
> to value of statistic regs. VF driver records value of statistic regs as base data
> when net interface is up or open, calculate increased count of regs during
> last period of online service and added it to saved_reset data. When user
> space collects statistic data, VF driver returns result of
> "current - base + saved_reset". "Current" is reg value at that point.
> 
> Restoring net function after migration just likes net interface is up or open.
> Call existed function to update base and saved_reset data to keep statistic
> data continual during migration.
> 
> Signed-off-by: Lan Tianyu <tianyu.lan@intel.com>
> ---
>  drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c | 3 +++
>  1 file changed, 3 insertions(+)
> 
> diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
> index 04b6ce7..d22160f 100644
> --- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
> +++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
> @@ -3005,6 +3005,7 @@ int ixgbevf_live_mg(struct ixgbevf_adapter *adapter)
>  			return 0;
>  
>  		del_timer_sync(&adapter->service_timer);
> +		ixgbevf_update_stats(adapter);
>  		pr_info("migration start\n");
>  		migration_status = MIGRATION_IN_PROGRESS; 
>  

So far, it seems that the only two things done when
starting migration are very small.

It doesn't seem worth it to let guests defer migration for things like
this.  Surely, cancelling a timer can be done later after VM is
migrated?



> @@ -3017,6 +3018,8 @@ int ixgbevf_live_mg(struct ixgbevf_adapter *adapter)
>  			return 1;
>  
>  		ixgbevf_restore_state(adapter);
> +		ixgbevf_save_reset_stats(adapter);
> +		ixgbevf_init_last_counter_stats(adapter);
>  		migration_status = MIGRATION_COMPLETED;
>  		pr_info("migration end\n");
>  		return 0;
> -- 
> 1.8.4.rc0.1.g8f6a3e5.dirty
> 
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diff mbox

Patch

diff --git a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
index 04b6ce7..d22160f 100644
--- a/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
+++ b/drivers/net/ethernet/intel/ixgbevf/ixgbevf_main.c
@@ -3005,6 +3005,7 @@  int ixgbevf_live_mg(struct ixgbevf_adapter *adapter)
 			return 0;
 
 		del_timer_sync(&adapter->service_timer);
+		ixgbevf_update_stats(adapter);
 		pr_info("migration start\n");
 		migration_status = MIGRATION_IN_PROGRESS; 
 
@@ -3017,6 +3018,8 @@  int ixgbevf_live_mg(struct ixgbevf_adapter *adapter)
 			return 1;
 
 		ixgbevf_restore_state(adapter);
+		ixgbevf_save_reset_stats(adapter);
+		ixgbevf_init_last_counter_stats(adapter);
 		migration_status = MIGRATION_COMPLETED;
 		pr_info("migration end\n");
 		return 0;