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 smtp4.osuosl.org (smtp4.osuosl.org [140.211.166.137]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 9BF88ECAAA1 for ; Tue, 30 Aug 2022 12:38:28 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp4.osuosl.org (Postfix) with ESMTP id E65C5415FF; Tue, 30 Aug 2022 12:38:27 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org E65C5415FF DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=osuosl.org; s=default; t=1661863108; bh=rnDsjmGJjaIB7D26jtBWUZYOr8HQiQiRjKGdrbhI67I=; h=From:To:Date:In-Reply-To:References:Subject:List-Id: List-Unsubscribe:List-Archive:List-Post:List-Help:List-Subscribe: Cc:From; b=xp/MueGGCgYe8uwvFm8WY4nRODuDBJtg9pPlmupV8VAEfo9OWQZqI0FEezm6Cs3tW N3xgedYlPPvPff+3/EvmQ/Ue6NPPPNs487qkhqHR+FNGYB4qnYamb4GEO00a/jTj6Z KwcCK3peL1hdjdccCJMe0z0nkNWRy1P/QQDHNYuH+Q88NmNXYn07bjxo/UF23LpAl1 Mn9y12G6MvXCI62f55gNRZCONhCen/NyP8ff5NOa3aucaqI3NVymv8TkdZBLUyTLOm 0x+V29AuqfDb59k56kqlDpQacMfKLf17PtAYaLcSCWi0/kNPULCzIX4fFrnvRwE0Qv oMCFBqDBBODjQ== X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp4.osuosl.org ([127.0.0.1]) by localhost (smtp4.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id q_rutmdU-HQt; Tue, 30 Aug 2022 12:38:25 +0000 (UTC) Received: from ash.osuosl.org (ash.osuosl.org [140.211.166.34]) by smtp4.osuosl.org (Postfix) with ESMTP id 3E24E41674; Tue, 30 Aug 2022 12:38:25 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp4.osuosl.org 3E24E41674 Received: from smtp3.osuosl.org (smtp3.osuosl.org [140.211.166.136]) by ash.osuosl.org (Postfix) with ESMTP id 9711D1BF3E9 for ; Tue, 30 Aug 2022 12:38:20 +0000 (UTC) Received: from localhost (localhost [127.0.0.1]) by smtp3.osuosl.org (Postfix) with ESMTP id 6ECF260FAC for ; Tue, 30 Aug 2022 12:38:20 +0000 (UTC) DKIM-Filter: OpenDKIM Filter v2.11.0 smtp3.osuosl.org 6ECF260FAC X-Virus-Scanned: amavisd-new at osuosl.org Received: from smtp3.osuosl.org ([127.0.0.1]) by localhost (smtp3.osuosl.org [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id wGUsX6M8UBBY for ; Tue, 30 Aug 2022 12:38:19 +0000 (UTC) X-Greylist: domain auto-whitelisted by SQLgrey-1.8.0 DKIM-Filter: OpenDKIM Filter v2.11.0 smtp3.osuosl.org 1F5ED60FA4 Received: from mga09.intel.com (mga09.intel.com [134.134.136.24]) by smtp3.osuosl.org (Postfix) with ESMTPS id 1F5ED60FA4 for ; Tue, 30 Aug 2022 12:38:18 +0000 (UTC) X-IronPort-AV: E=McAfee;i="6500,9779,10454"; a="295943122" X-IronPort-AV: E=Sophos;i="5.93,274,1654585200"; d="scan'208";a="295943122" Received: from orsmga006.jf.intel.com ([10.7.209.51]) by orsmga102.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 30 Aug 2022 05:38:18 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.93,274,1654585200"; d="scan'208";a="588585199" Received: from boxer.igk.intel.com ([10.102.20.173]) by orsmga006.jf.intel.com with ESMTP; 30 Aug 2022 05:38:17 -0700 From: Maciej Fijalkowski To: intel-wired-lan@lists.osuosl.org Date: Tue, 30 Aug 2022 14:38:02 +0200 Message-Id: <20220830123803.9361-2-maciej.fijalkowski@intel.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20220830123803.9361-1-maciej.fijalkowski@intel.com> References: <20220830123803.9361-1-maciej.fijalkowski@intel.com> MIME-Version: 1.0 X-Mailman-Original-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1661863099; x=1693399099; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=90P7fGfuhj3K+stD+JFr7Exph53pJwV1li4UPbJ6Kg4=; b=Bw/L6ZTpSMUlG0R77FbPdjRui6DmDhekkzQUcHr/CA2XCP9RvwSiDIO/ 0b/Xe+J/hFNoNlr78S2pnYgmBl7iACGshSP6IWVCNpRS3B73X/GgcSCah McOPWvz/2O+AWm2z2aLtlDr4MTNDg7juV8qDOHHe/yq3hbfgr378DoPHm VKgEtizQtxoT5UhJDLlO/9I9FWf1DCn5ywBWuiXTVR2DoQ0LcowFMgJF/ OAIvicop1JsgAprYrJwUTSx6VVAftRQ+2yTI/mBgDLB+xubJPmAIgmzn0 montuBivmU7BOV/X2hb6l9lYfdIrZsMwyyLA/osq/SMh/oLHmsrXzrt5f w==; X-Mailman-Original-Authentication-Results: smtp3.osuosl.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.a=rsa-sha256 header.s=Intel header.b=Bw/L6ZTp Subject: [Intel-wired-lan] [PATCH intel-net 1/2] ice: xsk: change batched Tx descriptor cleaning X-BeenThere: intel-wired-lan@osuosl.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Intel Wired Ethernet Linux Kernel Driver Development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, magnus.karlsson@intel.com Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: intel-wired-lan-bounces@osuosl.org Sender: "Intel-wired-lan" AF_XDP Tx descriptor cleaning in ice driver currently works in a "lazy" way - descriptors are not cleaned immediately after send. We rather hold on with cleaning until we see that free space in ring drops below particular threshold. This was supposed to reduce the amount of unnecessary work related to cleaning and instead of keeping the ring empty, ring was rather saturated. In AF_XDP realm cleaning Tx descriptors implies producing them to CQ. This is a way of letting know user space that particular descriptor has been sent, as John points out in [0]. We tried to implement serial descriptor cleaning which would be used in conjunction with batched cleaning but it made code base more convoluted and probably harder to maintain in future. Therefore we step away from batched cleaning in a current form in favor of an approach where we set RS bit on every last descriptor from a batch and clean always at the beginning of ice_xmit_zc(). This means that we give up a bit of Tx performance, but this doesn't hurt l2fwd scenario due to the fact that Tx side is much faster than Rx and Rx is the one that has to catch Tx up. txonly can be treaten as AF_XDP based packet generator. FWIW Tx descriptors are still produced in a batched way. Fixes: 126cdfe1007a ("ice: xsk: Improve AF_XDP ZC Tx and use batching API") [0]: https://lore.kernel.org/bpf/62b0a20232920_3573208ab@john.notmuch/ Fixes: 126cdfe1007a ("ice: xsk: Improve AF_XDP ZC Tx and use batching API") Signed-off-by: Maciej Fijalkowski --- drivers/net/ethernet/intel/ice/ice_txrx.c | 2 +- drivers/net/ethernet/intel/ice/ice_xsk.c | 143 +++++++++------------- drivers/net/ethernet/intel/ice/ice_xsk.h | 7 +- 3 files changed, 64 insertions(+), 88 deletions(-) diff --git a/drivers/net/ethernet/intel/ice/ice_txrx.c b/drivers/net/ethernet/intel/ice/ice_txrx.c index 836dce840712..b97d34d0741f 100644 --- a/drivers/net/ethernet/intel/ice/ice_txrx.c +++ b/drivers/net/ethernet/intel/ice/ice_txrx.c @@ -1464,7 +1464,7 @@ int ice_napi_poll(struct napi_struct *napi, int budget) bool wd; if (tx_ring->xsk_pool) - wd = ice_xmit_zc(tx_ring, ICE_DESC_UNUSED(tx_ring), budget); + wd = ice_xmit_zc(tx_ring); else if (ice_ring_is_xdp(tx_ring)) wd = true; else diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.c b/drivers/net/ethernet/intel/ice/ice_xsk.c index 49ba8bfdbf04..46efe72d1342 100644 --- a/drivers/net/ethernet/intel/ice/ice_xsk.c +++ b/drivers/net/ethernet/intel/ice/ice_xsk.c @@ -719,69 +719,57 @@ ice_clean_xdp_tx_buf(struct ice_tx_ring *xdp_ring, struct ice_tx_buf *tx_buf) } /** - * ice_clean_xdp_irq_zc - Reclaim resources after transmit completes on XDP ring - * @xdp_ring: XDP ring to clean - * @napi_budget: amount of descriptors that NAPI allows us to clean - * - * Returns count of cleaned descriptors + * ice_clean_xdp_irq_zc - produce AF_XDP descriptors to CQ + * @xdp_ring: XDP Tx ring */ -static u16 ice_clean_xdp_irq_zc(struct ice_tx_ring *xdp_ring, int napi_budget) +static void ice_clean_xdp_irq_zc(struct ice_tx_ring *xdp_ring) { - u16 tx_thresh = ICE_RING_QUARTER(xdp_ring); - int budget = napi_budget / tx_thresh; - u16 next_dd = xdp_ring->next_dd; - u16 ntc, cleared_dds = 0; - - do { - struct ice_tx_desc *next_dd_desc; - u16 desc_cnt = xdp_ring->count; - struct ice_tx_buf *tx_buf; - u32 xsk_frames; - u16 i; - - next_dd_desc = ICE_TX_DESC(xdp_ring, next_dd); - if (!(next_dd_desc->cmd_type_offset_bsz & - cpu_to_le64(ICE_TX_DESC_DTYPE_DESC_DONE))) - break; + u16 ntc = xdp_ring->next_to_clean; + struct ice_tx_desc *tx_desc; + u16 cnt = xdp_ring->count; + struct ice_tx_buf *tx_buf; + u16 xsk_frames = 0; + u16 last_rs; + int i; - cleared_dds++; - xsk_frames = 0; - if (likely(!xdp_ring->xdp_tx_active)) { - xsk_frames = tx_thresh; - goto skip; - } + last_rs = xdp_ring->next_to_use ? xdp_ring->next_to_use - 1 : cnt - 1; + tx_desc = ICE_TX_DESC(xdp_ring, last_rs); + if ((tx_desc->cmd_type_offset_bsz & + cpu_to_le64(ICE_TX_DESC_DTYPE_DESC_DONE))) { + if (last_rs >= ntc) + xsk_frames = last_rs - ntc + 1; + else + xsk_frames = last_rs + cnt - ntc + 1; + } - ntc = xdp_ring->next_to_clean; + if (!xsk_frames) + return; - for (i = 0; i < tx_thresh; i++) { - tx_buf = &xdp_ring->tx_buf[ntc]; + if (likely(!xdp_ring->xdp_tx_active)) + goto skip; - if (tx_buf->raw_buf) { - ice_clean_xdp_tx_buf(xdp_ring, tx_buf); - tx_buf->raw_buf = NULL; - } else { - xsk_frames++; - } + ntc = xdp_ring->next_to_clean; + for (i = 0; i < xsk_frames; i++) { + tx_buf = &xdp_ring->tx_buf[ntc]; - ntc++; - if (ntc >= xdp_ring->count) - ntc = 0; + if (tx_buf->raw_buf) { + ice_clean_xdp_tx_buf(xdp_ring, tx_buf); + tx_buf->raw_buf = NULL; + } else { + xsk_frames++; } + + ntc++; + if (ntc >= xdp_ring->count) + ntc = 0; + } skip: - xdp_ring->next_to_clean += tx_thresh; - if (xdp_ring->next_to_clean >= desc_cnt) - xdp_ring->next_to_clean -= desc_cnt; - if (xsk_frames) - xsk_tx_completed(xdp_ring->xsk_pool, xsk_frames); - next_dd_desc->cmd_type_offset_bsz = 0; - next_dd = next_dd + tx_thresh; - if (next_dd >= desc_cnt) - next_dd = tx_thresh - 1; - } while (--budget); - - xdp_ring->next_dd = next_dd; - - return cleared_dds * tx_thresh; + tx_desc->cmd_type_offset_bsz = 0; + xdp_ring->next_to_clean += xsk_frames; + if (xdp_ring->next_to_clean >= cnt) + xdp_ring->next_to_clean -= cnt; + if (xsk_frames) + xsk_tx_completed(xdp_ring->xsk_pool, xsk_frames); } /** @@ -816,7 +804,6 @@ static void ice_xmit_pkt(struct ice_tx_ring *xdp_ring, struct xdp_desc *desc, static void ice_xmit_pkt_batch(struct ice_tx_ring *xdp_ring, struct xdp_desc *descs, unsigned int *total_bytes) { - u16 tx_thresh = ICE_RING_QUARTER(xdp_ring); u16 ntu = xdp_ring->next_to_use; struct ice_tx_desc *tx_desc; u32 i; @@ -836,13 +823,6 @@ static void ice_xmit_pkt_batch(struct ice_tx_ring *xdp_ring, struct xdp_desc *de } xdp_ring->next_to_use = ntu; - - if (xdp_ring->next_to_use > xdp_ring->next_rs) { - tx_desc = ICE_TX_DESC(xdp_ring, xdp_ring->next_rs); - tx_desc->cmd_type_offset_bsz |= - cpu_to_le64(ICE_TX_DESC_CMD_RS << ICE_TXD_QW1_CMD_S); - xdp_ring->next_rs += tx_thresh; - } } /** @@ -855,7 +835,6 @@ static void ice_xmit_pkt_batch(struct ice_tx_ring *xdp_ring, struct xdp_desc *de static void ice_fill_tx_hw_ring(struct ice_tx_ring *xdp_ring, struct xdp_desc *descs, u32 nb_pkts, unsigned int *total_bytes) { - u16 tx_thresh = ICE_RING_QUARTER(xdp_ring); u32 batched, leftover, i; batched = ALIGN_DOWN(nb_pkts, PKTS_PER_BATCH); @@ -864,54 +843,54 @@ static void ice_fill_tx_hw_ring(struct ice_tx_ring *xdp_ring, struct xdp_desc *d ice_xmit_pkt_batch(xdp_ring, &descs[i], total_bytes); for (; i < batched + leftover; i++) ice_xmit_pkt(xdp_ring, &descs[i], total_bytes); +} - if (xdp_ring->next_to_use > xdp_ring->next_rs) { - struct ice_tx_desc *tx_desc; +/** + * ice_set_rs_bit - set RS bit on last produced descriptor (one behind current NTU) + * @xdp_ring: XDP ring to produce the HW Tx descriptors on + */ +static void ice_set_rs_bit(struct ice_tx_ring *xdp_ring) +{ + u16 ntu = xdp_ring->next_to_use ? xdp_ring->next_to_use - 1 : xdp_ring->count - 1; + struct ice_tx_desc *tx_desc; - tx_desc = ICE_TX_DESC(xdp_ring, xdp_ring->next_rs); - tx_desc->cmd_type_offset_bsz |= - cpu_to_le64(ICE_TX_DESC_CMD_RS << ICE_TXD_QW1_CMD_S); - xdp_ring->next_rs += tx_thresh; - } + tx_desc = ICE_TX_DESC(xdp_ring, ntu); + tx_desc->cmd_type_offset_bsz |= + cpu_to_le64(ICE_TX_DESC_CMD_RS << ICE_TXD_QW1_CMD_S); } /** * ice_xmit_zc - take entries from XSK Tx ring and place them onto HW Tx ring * @xdp_ring: XDP ring to produce the HW Tx descriptors on - * @budget: number of free descriptors on HW Tx ring that can be used - * @napi_budget: amount of descriptors that NAPI allows us to clean * * Returns true if there is no more work that needs to be done, false otherwise */ -bool ice_xmit_zc(struct ice_tx_ring *xdp_ring, u32 budget, int napi_budget) +bool ice_xmit_zc(struct ice_tx_ring *xdp_ring) { struct xdp_desc *descs = xdp_ring->xsk_pool->tx_descs; - u16 tx_thresh = ICE_RING_QUARTER(xdp_ring); u32 nb_pkts, nb_processed = 0; unsigned int total_bytes = 0; + int budget; + + ice_clean_xdp_irq_zc(xdp_ring); - if (budget < tx_thresh) - budget += ice_clean_xdp_irq_zc(xdp_ring, napi_budget); + budget = ICE_DESC_UNUSED(xdp_ring); + budget = min_t(u16, budget, ICE_RING_QUARTER(xdp_ring)); nb_pkts = xsk_tx_peek_release_desc_batch(xdp_ring->xsk_pool, budget); if (!nb_pkts) return true; if (xdp_ring->next_to_use + nb_pkts >= xdp_ring->count) { - struct ice_tx_desc *tx_desc; - nb_processed = xdp_ring->count - xdp_ring->next_to_use; ice_fill_tx_hw_ring(xdp_ring, descs, nb_processed, &total_bytes); - tx_desc = ICE_TX_DESC(xdp_ring, xdp_ring->next_rs); - tx_desc->cmd_type_offset_bsz |= - cpu_to_le64(ICE_TX_DESC_CMD_RS << ICE_TXD_QW1_CMD_S); - xdp_ring->next_rs = tx_thresh - 1; xdp_ring->next_to_use = 0; } ice_fill_tx_hw_ring(xdp_ring, &descs[nb_processed], nb_pkts - nb_processed, &total_bytes); + ice_set_rs_bit(xdp_ring); ice_xdp_ring_update_tail(xdp_ring); ice_update_tx_ring_stats(xdp_ring, nb_pkts, total_bytes); diff --git a/drivers/net/ethernet/intel/ice/ice_xsk.h b/drivers/net/ethernet/intel/ice/ice_xsk.h index 21faec8e97db..35dd3c57c4df 100644 --- a/drivers/net/ethernet/intel/ice/ice_xsk.h +++ b/drivers/net/ethernet/intel/ice/ice_xsk.h @@ -26,12 +26,9 @@ bool ice_alloc_rx_bufs_zc(struct ice_rx_ring *rx_ring, u16 count); bool ice_xsk_any_rx_ring_ena(struct ice_vsi *vsi); void ice_xsk_clean_rx_ring(struct ice_rx_ring *rx_ring); void ice_xsk_clean_xdp_ring(struct ice_tx_ring *xdp_ring); -bool ice_xmit_zc(struct ice_tx_ring *xdp_ring, u32 budget, int napi_budget); +bool ice_xmit_zc(struct ice_tx_ring *xdp_ring); #else -static inline bool -ice_xmit_zc(struct ice_tx_ring __always_unused *xdp_ring, - u32 __always_unused budget, - int __always_unused napi_budget) +ice_xmit_zc(struct ice_tx_ring __always_unused *xdp_ring) { return false; } -- 2.34.1 _______________________________________________ Intel-wired-lan mailing list Intel-wired-lan@osuosl.org https://lists.osuosl.org/mailman/listinfo/intel-wired-lan