From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id EABBC3D3B8 for ; Wed, 12 Feb 2025 01:44:40 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739324681; cv=none; b=B6F91Xvs//9ofnenAsFJXG3CIoRWs0NSG1q215g+t1bWUFG3gAOrdDk1sLZuR0TrPfOKbmV/F4CLP+sXbMD7w7anHRGVpWqFng05fxP/AVj97KzX4M682PjhqFanAILWLfHiqCruyyxc2sPDyfjsEYcGD+HPp0h3p4wFaiL14kA= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1739324681; c=relaxed/simple; bh=vwjvqa486loabkKY0VkIST3XHnIBYBzMM7doYaiNR/Q=; h=Date:From:To:Cc:Subject:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=ZdV0hHidPrWZH5nwkp9adieFybnucRvo4XK7KbOXZhm1YvfwYjryC010rWD7H7ER9LOA29shAFjXhHAv+eDLDHuPerHWrZaxiOHgRqd1Gk/n67EpYZ8YpHIdzq3j9y2upSpWdh1j72Lw9djRcszFHLmzY6OAlkICjZ6bX9PleAQ= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=tnzHSsTD; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="tnzHSsTD" Received: by smtp.kernel.org (Postfix) with ESMTPSA id BE539C4CEDD; Wed, 12 Feb 2025 01:44:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1739324680; bh=vwjvqa486loabkKY0VkIST3XHnIBYBzMM7doYaiNR/Q=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=tnzHSsTD/QT5FAF40L1aBMrcQtToDNbmGxNMBlmZ58KUsqPptYyLKEUJigqU6BkAl 5P1W4Ew7QpxreIHsWkETl2ymBmS9SWfmqKrzfBza6udRpi0NkGbN1+mbIL+DwcYwF/ 9GNfuODXi1dc79tftUV7eDK6Hno7RtjElviRPKtZf9ZG3oCj8QoR7QcKDX5RMmQVnV BTb5Ny5aYvzcGDJZhZSNVVXuDzhFU4VExvYLPsDEto4bxyMW+WQbEk2m02ycnoTCbs qOe8whEsaDWHhuSAZ3wVbU2+V9T2D7ANR84Du0p0eV/0d9bSXv9BdKbkge2VodnvwZ bGEKB3wJe1OYA== Date: Tue, 11 Feb 2025 17:44:38 -0800 From: Jakub Kicinski To: Michael Chan Cc: davem@davemloft.net, netdev@vger.kernel.org, edumazet@google.com, pabeni@redhat.com, andrew+netdev@lunn.ch, pavan.chebbi@broadcom.com, andrew.gospodarek@broadcom.com, michal.swiatkowski@linux.intel.com, helgaas@kernel.org, horms@kernel.org, Somnath Kotur , Ajit Khaparde , David Wei Subject: Re: [PATCH net-next v4 09/10] bnxt_en: Extend queue stop/start for TX rings Message-ID: <20250211174438.3b8493fe@kernel.org> In-Reply-To: <20250208202916.1391614-10-michael.chan@broadcom.com> References: <20250208202916.1391614-1-michael.chan@broadcom.com> <20250208202916.1391614-10-michael.chan@broadcom.com> Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit On Sat, 8 Feb 2025 12:29:15 -0800 Michael Chan wrote: > + rc = bnxt_hwrm_cp_ring_alloc_p5(bp, txr->tx_cpr); > + if (rc) > + return rc; > + > + rc = bnxt_hwrm_tx_ring_alloc(bp, txr, false); > + if (rc) > + return rc; Under what circumstances can these alloc calls fail? "alloc" sounds concerning in a start call. > + txr->tx_prod = 0; > + txr->tx_cons = 0; > + txr->tx_hw_cons = 0; > cpr->sw_stats->rx.rx_resets++; > > + if (bp->flags & BNXT_FLAG_SHARED_RINGS) { > + cpr->sw_stats->tx.tx_resets++; Is there a reason why queue op stop/start cycles are counted as resets? IIUC previously only faults (~errors) would be counted as resets. ifdown / ifup or ring reconfig (ethtool -L / -G) would not increment resets. I think queue reconfig is more like ethtool -L than a fault. It'd be more consistent with existing code not to increment these counters. > + rc = bnxt_tx_queue_start(bp, idx); > + if (rc) { > + netdev_warn(bp->dev, > + "tx queue restart failed: rc=%d\n", rc); > + bnapi->tx_fault = 1; > + goto err_reset; > + } > + } > + > + napi_enable(&bnapi->napi); Here you first start the queue then enable NAPI... > + bnxt_db_nq_arm(bp, &cpr->cp_db, cpr->cp_raw_cons); > + > for (i = 0; i <= BNXT_VNIC_NTUPLE; i++) { > vnic = &bp->vnic_info[i]; > > @@ -15716,17 +15820,25 @@ static int bnxt_queue_stop(struct net_device *dev, void *qmem, int idx) > /* Make sure NAPI sees that the VNIC is disabled */ > synchronize_net(); > rxr = &bp->rx_ring[idx]; > - cancel_work_sync(&rxr->bnapi->cp_ring.dim.work); > + bnapi = rxr->bnapi; > + cpr = &bnapi->cp_ring; > + cancel_work_sync(&cpr->dim.work); > bnxt_hwrm_rx_ring_free(bp, rxr, false); > bnxt_hwrm_rx_agg_ring_free(bp, rxr, false); > page_pool_disable_direct_recycling(rxr->page_pool); > if (bnxt_separate_head_pool()) > page_pool_disable_direct_recycling(rxr->head_pool); > > + if (bp->flags & BNXT_FLAG_SHARED_RINGS) > + bnxt_tx_queue_stop(bp, idx); > + > + napi_disable(&bnapi->napi); ... but here you do the opposite, and require extra synchronization in bnxt_tx_queue_stop() to set your magic flag, sync the NAPI etc. Why can't the start and stop paths be the mirror image?