From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 6F935C433FE for ; Wed, 6 Apr 2022 17:53:48 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S239639AbiDFRzq (ORCPT ); Wed, 6 Apr 2022 13:55:46 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37076 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S239665AbiDFRza (ORCPT ); Wed, 6 Apr 2022 13:55:30 -0400 Received: from mga17.intel.com (mga17.intel.com [192.55.52.151]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 9E72747D902; Wed, 6 Apr 2022 09:05:01 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1649261101; x=1680797101; h=date:from:to:cc:subject:message-id:references: mime-version:in-reply-to; bh=LCEP7z9iVmnS+5YAekuvbdZXgDguf3alCnSjdIOWx8s=; b=WBKxCHmeIAWijuDTdtcq3IqrMUyvYrM2RVVgzPTiIc2WgKfJ6yysGy3Z 8rd/efJA7XS0KtRepAtjjKPxdUqbzL0TRjxz/sPqMab+Hlw5wivXtyiAO 8UgI+ebsFJLsJ6TOgBhbSSwkvR5VjqwycSNQYr7mvLjZh0eagVVZNp971 e8LsxPReHC03nXQfQjrWCrO4NQhsc/Brsm/SGzWasY+ly+QGlzUvTFu1g O6pIKYomFTEL4lz51bx5qe/MmBQI+loX5yw+vzly10CS69F1abI4tY+7h mq1Z+9g+T6SUmB9Wy2GtgqzblWFntZNaLPR796vSFmVNkuGegur8QdwHz A==; X-IronPort-AV: E=McAfee;i="6200,9189,10309"; a="241676579" X-IronPort-AV: E=Sophos;i="5.90,240,1643702400"; d="scan'208";a="241676579" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga107.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Apr 2022 09:05:01 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.90,240,1643702400"; d="scan'208";a="608953323" Received: from boxer.igk.intel.com (HELO boxer) ([10.102.20.173]) by fmsmga008.fm.intel.com with ESMTP; 06 Apr 2022 09:04:58 -0700 Date: Wed, 6 Apr 2022 18:04:58 +0200 From: Maciej Fijalkowski To: Jesper Dangaard Brouer Cc: bpf@vger.kernel.org, ast@kernel.org, daniel@iogearbox.net, magnus.karlsson@intel.com, bjorn@kernel.org, brouer@redhat.com, netdev@vger.kernel.org, maximmi@nvidia.com, alexandr.lobakin@intel.com, Toke Hoiland Jorgensen Subject: Re: [PATCH bpf-next 04/10] i40e: xsk: terminate NAPI when XSK Rx queue gets full Message-ID: References: <20220405110631.404427-1-maciej.fijalkowski@intel.com> <20220405110631.404427-5-maciej.fijalkowski@intel.com> <8bb40f98-2f1f-c331-23d4-ed94a6a1ce76@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <8bb40f98-2f1f-c331-23d4-ed94a6a1ce76@redhat.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, Apr 05, 2022 at 03:04:17PM +0200, Jesper Dangaard Brouer wrote: > > > On 05/04/2022 13.06, Maciej Fijalkowski wrote: > > Correlate -ENOBUFS that was returned from xdp_do_redirect() with a XSK > > Rx queue being full. In such case, terminate the softirq processing and > > let the user space to consume descriptors from XSK Rx queue so that > > there is room that driver can use later on. > > > > Signed-off-by: Maciej Fijalkowski > > --- > > .../ethernet/intel/i40e/i40e_txrx_common.h | 1 + > > drivers/net/ethernet/intel/i40e/i40e_xsk.c | 21 ++++++++++++------- > > 2 files changed, 15 insertions(+), 7 deletions(-) > > > [...] > > I noticed you are only doing this for the Zero-Copy variants. > Wouldn't this also be a benefit for normal AF_XDP ? Sorry for the delay, indeed this would improve AF_XDP in copy mode as well, but only after a fix I have sent (not on lore yet :<). I'll adjust patches to check for -ENOBUFS in $DRIVER_txrx.c and send a v2. > > > > diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c > > index c1d25b0b0ca2..9f9e4ce9a24d 100644 > > --- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c > > +++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c > > @@ -161,9 +161,10 @@ static int i40e_run_xdp_zc(struct i40e_ring *rx_ring, struct xdp_buff *xdp) > > if (likely(act == XDP_REDIRECT)) { > > err = xdp_do_redirect(rx_ring->netdev, xdp, xdp_prog); > > - if (err) > > - goto out_failure; > > - return I40E_XDP_REDIR; > > + if (!err) > > + return I40E_XDP_REDIR; > > + result = (err == -ENOBUFS) ? I40E_XDP_EXIT : I40E_XDP_CONSUMED; > > + goto out_failure; > > } > > switch (act) { > > @@ -175,6 +176,9 @@ static int i40e_run_xdp_zc(struct i40e_ring *rx_ring, struct xdp_buff *xdp) > > if (result == I40E_XDP_CONSUMED) > > goto out_failure; > > break; > > + case XDP_DROP: > > + result = I40E_XDP_CONSUMED; > > + break; > > default: > > bpf_warn_invalid_xdp_action(rx_ring->netdev, xdp_prog, act); > > fallthrough; > > @@ -182,9 +186,6 @@ static int i40e_run_xdp_zc(struct i40e_ring *rx_ring, struct xdp_buff *xdp) > > out_failure: > > trace_xdp_exception(rx_ring->netdev, xdp_prog, act); > > fallthrough; /* handle aborts by dropping packet */ > > - case XDP_DROP: > > - result = I40E_XDP_CONSUMED; > > - break; > > } > > return result; > > } > > @@ -370,6 +371,12 @@ int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget) > > xsk_buff_dma_sync_for_cpu(bi, rx_ring->xsk_pool); > > xdp_res = i40e_run_xdp_zc(rx_ring, bi); > > + if (xdp_res == I40E_XDP_EXIT) { > > + failure = true; > > + xsk_buff_free(bi); > > + next_to_clean = (next_to_clean + 1) & count_mask; > > + break; > > + } > > i40e_handle_xdp_result_zc(rx_ring, bi, rx_desc, &rx_packets, > > &rx_bytes, size, xdp_res); > > total_rx_packets += rx_packets; > > @@ -382,7 +389,7 @@ int i40e_clean_rx_irq_zc(struct i40e_ring *rx_ring, int budget) > > cleaned_count = (next_to_clean - rx_ring->next_to_use - 1) & count_mask; > > if (cleaned_count >= I40E_RX_BUFFER_WRITE) > > - failure = !i40e_alloc_rx_buffers_zc(rx_ring, cleaned_count); > > + failure |= !i40e_alloc_rx_buffers_zc(rx_ring, cleaned_count); > > i40e_finalize_xdp_rx(rx_ring, xdp_xmit); > > i40e_update_rx_stats(rx_ring, total_rx_bytes, total_rx_packets); > > >