[PATCH 1/2][SRU][B] i40e: Do not allow use more TC queue pairs than MSI-X vectors exist

[Juerg Haefliger]

On Tue, 26 Mar 2019 14:00:47 +0530
Nivedita Singhvi <nivedita.singhvi at canonical.com> wrote:

> From: Paweł Jabłoński <pawel.jablonski at intel.com>
> 
> BugLink: https://bugs.launchpad.net/bugs/1820948
> 
> This patch suppresses the message about invalid TC mapping and wrong
> selected TX queue. The root cause of this bug was setting too many
> TC queue pairs on huge multiprocessor machines. When quantity of the
> TC queue pairs is exceeding MSI-X vectors count then TX queue number
> can be selected beyond actual TX queues amount.
> 
> Signed-off-by: Paweł Jabłoński <pawel.jablonski at intel.com>
> Tested-by: Andrew Bowers <andrewx.bowers at intel.com>
> Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher at intel.com>
> (cherry-picked from commit 1563f2d2e01242f05dd523ffd56fe104bc1afd58)


Should be 'cherry picked from ...' (no dash) as added by 'git cherry-pick -x'

...Juerg


> Signed-off-by: Nivedita Singhvi <nivedita.singhvi at canonical.com>
> ---
>  drivers/net/ethernet/intel/i40e/i40e_main.c | 4 ++++
>  1 file changed, 4 insertions(+)
> 
> diff --git a/drivers/net/ethernet/intel/i40e/i40e_main.c b/drivers/net/ethernet/intel/i40e/i40e_main.c
> index 08f7bd9001bc..8ad1710804f6 100644
> --- a/drivers/net/ethernet/intel/i40e/i40e_main.c
> +++ b/drivers/net/ethernet/intel/i40e/i40e_main.c
> @@ -1818,6 +1818,10 @@ static void i40e_vsi_setup_queue_map(struct i40e_vsi *vsi,
>  	num_tc_qps = qcount / numtc;
>  	num_tc_qps = min_t(int, num_tc_qps, i40e_pf_get_max_q_per_tc(pf));
>  
> +	/* Do not allow use more TC queue pairs than MSI-X vectors exist */
> +	if (pf->flags & I40E_FLAG_MSIX_ENABLED)
> +		num_tc_qps = min_t(int, num_tc_qps, pf->num_lan_msix);
> +
>  	/* Setup queue offset/count for all TCs for given VSI */
>  	for (i = 0; i < I40E_MAX_TRAFFIC_CLASS; i++) {
>  		/* See if the given TC is enabled for the given VSI */

-------------- next part --------------
A non-text attachment was scrubbed...
Name: not available
Type: application/pgp-signature
Size: 833 bytes
Desc: OpenPGP digital signature
URL: <https://lists.ubuntu.com/archives/kernel-team/attachments/20190326/4c6e2d73/attachment.sig>