[next,S70,03/12] i40e: don't hold RTNL lock while waiting for VF reset to finish

From: Jacob Keller <jacob.e.keller@intel.com>

We made some effort to reduce the RTNL lock scope when resetting and
rebuilding the PF. Unfortunately we still held the RTNL lock during the
VF reset operation, which meant that multiple PFs could not reset in
parallel due to the global lock. For now, further reduce the scope by
not holding the RTNL lock while resetting VFs. This allows multiple PFs
to reset in a timely manner.

Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
Change-ID: I2fbf823a0063f24dff67676cad09f0bbf83ee4ce
---
 drivers/net/ethernet/intel/i40e/i40e_main.c | 11 +++++++++--
 1 file changed, 9 insertions(+), 2 deletions(-)

ACK

Thanks,
Jake

> -----Original Message-----
> From: Michael, Alice
> Sent: Thursday, April 13, 2017 1:46 AM
> To: Michael, Alice <alice.michael@intel.com>; intel-wired-lan@lists.osuosl.org
> Cc: Keller, Jacob E <jacob.e.keller@intel.com>
> Subject: [next PATCH S70 03/12] i40e: don't hold RTNL lock while waiting for VF
> reset to finish
> 
> From: Jacob Keller <jacob.e.keller@intel.com>
> 
> We made some effort to reduce the RTNL lock scope when resetting and
> rebuilding the PF. Unfortunately we still held the RTNL lock during the
> VF reset operation, which meant that multiple PFs could not reset in
> parallel due to the global lock. For now, further reduce the scope by
> not holding the RTNL lock while resetting VFs. This allows multiple PFs
> to reset in a timely manner.
> 
> Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
> Change-ID: I2fbf823a0063f24dff67676cad09f0bbf83ee4ce
> ---
>  drivers/net/ethernet/intel/i40e/i40e_main.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c
> b/drivers/net/ethernet/intel/i40e/i40e_main.c
> index 4b507ce..1c06693 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_main.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
> @@ -7151,6 +7151,10 @@ static void i40e_rebuild(struct i40e_pf *pf, bool reinit,
> bool lock_acquired)
>  	/* restart the VSIs that were rebuilt and running before the reset */
>  	i40e_pf_unquiesce_all_vsi(pf);
> 
> +	/* Release the RTNL lock before we start resetting VFs */
> +	if (!lock_acquired)
> +		rtnl_unlock();
> +
>  	if (pf->num_alloc_vfs) {
>  		for (v = 0; v < pf->num_alloc_vfs; v++)
>  			i40e_reset_vf(&pf->vf[v], true);
> @@ -7159,9 +7163,12 @@ static void i40e_rebuild(struct i40e_pf *pf, bool reinit,
> bool lock_acquired)
>  	/* tell the firmware that we're starting */
>  	i40e_send_version(pf);
> 
> +	/* We've already released the lock, so don't do it again */
> +	goto end_core_reset;
> +
>  end_unlock:
> -if (!lock_acquired)
> -	rtnl_unlock();
> +	if (!lock_acquired)
> +		rtnl_unlock();
>  end_core_reset:
>  	clear_bit(__I40E_RESET_FAILED, &pf->state);
>  clear_recovery:
> --
> 2.9.3

> -----Original Message-----
> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@lists.osuosl.org] On
> Behalf Of Alice Michael
> Sent: Thursday, April 13, 2017 1:46 AM
> To: Michael, Alice <alice.michael@intel.com>; intel-wired-
> lan@lists.osuosl.org
> Subject: [Intel-wired-lan] [next PATCH S70 03/12] i40e: don't hold RTNL lock
> while waiting for VF reset to finish
> 
> From: Jacob Keller <jacob.e.keller@intel.com>
> 
> We made some effort to reduce the RTNL lock scope when resetting and
> rebuilding the PF. Unfortunately we still held the RTNL lock during the VF
> reset operation, which meant that multiple PFs could not reset in parallel due
> to the global lock. For now, further reduce the scope by not holding the RTNL
> lock while resetting VFs. This allows multiple PFs to reset in a timely manner.
> 
> Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
> Change-ID: I2fbf823a0063f24dff67676cad09f0bbf83ee4ce
> ---
>  drivers/net/ethernet/intel/i40e/i40e_main.c | 11 +++++++++--
>  1 file changed, 9 insertions(+), 2 deletions(-)

Tested-by: Andrew Bowers <andrewx.bowers@intel.com>