[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <ZroIF3eSlQuAk9Zx@boxer>
Date: Mon, 12 Aug 2024 15:03:19 +0200
From: Maciej Fijalkowski <maciej.fijalkowski@...el.com>
To: Larysa Zaremba <larysa.zaremba@...el.com>
CC: <intel-wired-lan@...ts.osuosl.org>, Tony Nguyen
<anthony.l.nguyen@...el.com>, "David S. Miller" <davem@...emloft.net>, "Jacob
Keller" <jacob.e.keller@...el.com>, Eric Dumazet <edumazet@...gle.com>,
"Jakub Kicinski" <kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>, "Alexei
Starovoitov" <ast@...nel.org>, Daniel Borkmann <daniel@...earbox.net>,
"Jesper Dangaard Brouer" <hawk@...nel.org>, John Fastabend
<john.fastabend@...il.com>, <netdev@...r.kernel.org>,
<linux-kernel@...r.kernel.org>, <bpf@...r.kernel.org>,
<magnus.karlsson@...el.com>, Michal Kubiak <michal.kubiak@...el.com>,
Wojciech Drewek <wojciech.drewek@...el.com>, Amritha Nambiar
<amritha.nambiar@...el.com>
Subject: Re: [PATCH iwl-net v2 5/6] ice: remove ICE_CFG_BUSY locking from
AF_XDP code
On Wed, Jul 24, 2024 at 06:48:36PM +0200, Larysa Zaremba wrote:
> Locking used in ice_qp_ena() and ice_qp_dis() does pretty much nothing,
> because ICE_CFG_BUSY is a state flag that is supposed to be set in a PF
> state, not VSI one. Therefore it does not protect the queue pair from
> e.g. reset.
>
> Despite being useless, it still can deadlock the unfortunate functions that
> have fell into the same ICE_CFG_BUSY-VSI trap. This happens if ice_qp_ena
> returns an error.
>
> Remove ICE_CFG_BUSY locking from ice_qp_dis() and ice_qp_ena().
Why not just check the pf->state ? And address other broken callsites?
>
> Fixes: 2d4238f55697 ("ice: Add support for AF_XDP")
> Reviewed-by: Wojciech Drewek <wojciech.drewek@...el.com>
> Signed-off-by: Larysa Zaremba <larysa.zaremba@...el.com>
> ---
> drivers/net/ethernet/intel/ice/ice_xsk.c | 9 ---------
> 1 file changed, 9 deletions(-)
>
> diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c
> index 5dd50a2866cc..d23fd4ea9129 100644
> --- a/drivers/net/ethernet/intel/ice/ice_xsk.c
> +++ b/drivers/net/ethernet/intel/ice/ice_xsk.c
> @@ -163,7 +163,6 @@ static int ice_qp_dis(struct ice_vsi *vsi, u16 q_idx)
> struct ice_q_vector *q_vector;
> struct ice_tx_ring *tx_ring;
> struct ice_rx_ring *rx_ring;
> - int timeout = 50;
> int err;
>
> if (q_idx >= vsi->num_rxq || q_idx >= vsi->num_txq)
> @@ -173,13 +172,6 @@ static int ice_qp_dis(struct ice_vsi *vsi, u16 q_idx)
> rx_ring = vsi->rx_rings[q_idx];
> q_vector = rx_ring->q_vector;
>
> - while (test_and_set_bit(ICE_CFG_BUSY, vsi->state)) {
> - timeout--;
> - if (!timeout)
> - return -EBUSY;
> - usleep_range(1000, 2000);
> - }
> -
> ice_qvec_dis_irq(vsi, rx_ring, q_vector);
> ice_qvec_toggle_napi(vsi, q_vector, false);
>
> @@ -250,7 +242,6 @@ static int ice_qp_ena(struct ice_vsi *vsi, u16 q_idx)
> ice_qvec_ena_irq(vsi, q_vector);
>
> netif_tx_start_queue(netdev_get_tx_queue(vsi->netdev, q_idx));
> - clear_bit(ICE_CFG_BUSY, vsi->state);
>
> return 0;
> }
> --
> 2.43.0
>
Powered by blists - more mailing lists