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 66BBCC00140 for ; Mon, 15 Aug 2022 06:01:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230155AbiHOGAk (ORCPT ); Mon, 15 Aug 2022 02:00:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57558 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232779AbiHOGAc (ORCPT ); Mon, 15 Aug 2022 02:00:32 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.129.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 024C86591 for ; Sun, 14 Aug 2022 23:00:29 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1660543228; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=lAdBQK0QiV5b4wlrykjTQFv9XF+6GUWZgv1gebJc3GA=; b=R4otm83mg2WWPcyXkzhdW+bEG/o35UKX1LXf6LqtykdATjKfab7ICZkLQXrAcQMthy+mZx Ybffz+NFbNkho+eIvsE+S2SugKf/B2QgPxe5bQNOEkdQitcH0T/fqeUo/NkLEWulq3yjNr oP8wyxAcFpzGSOWAjRGNdisYjyKw+6w= Received: from mail-ed1-f70.google.com (mail-ed1-f70.google.com [209.85.208.70]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_128_GCM_SHA256) id us-mta-169-kSuvfyZgND-TsC8mQDltTw-1; Mon, 15 Aug 2022 02:00:27 -0400 X-MC-Unique: kSuvfyZgND-TsC8mQDltTw-1 Received: by mail-ed1-f70.google.com with SMTP id s21-20020a056402521500b00440e91f30easo4123427edd.7 for ; Sun, 14 Aug 2022 23:00:27 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc; bh=lAdBQK0QiV5b4wlrykjTQFv9XF+6GUWZgv1gebJc3GA=; b=Y/ztdEosiyYlwo7mLg0d7LAegWlsCICnM3+1eWGNLNQBE1VDjnYvVPecvK/BEzQfzx gxPSTYe+Lw11KzVwJCNsCVL3048Ejc9akVhaMkJI7XvXdzHF0CxAG9SSN2XzdFOukJzP Dy2YmtfyLOSYGfC0mCcQZbRJiaDwdj9Q4N3slyOLMR716zGZxRjR2vL6iuLNXhOCyRft L5wipFyNcr2nybvrKwRbsDMb6rXTBXo7UUW6IsveJE2+lkCIp6CxcchC6nCHHPacqZUl DCNKTRMt8hKRTy1uLqWsy6A7JmHIuLHMgFcx8JwrYG7vsXlif+/PFkJAyaFENQVB0cIV L1Fw== X-Gm-Message-State: ACgBeo3oM5BAKrc1bdasRQw47WkdVtbfZ1QDAcLMl2clnKlLVr0tzGli xmcxJsbyTl8qp/lLHlgDqBMPBrjoOt/N7ifpbfjHJRbfIVqnrrNbV/kJGZa4eKokxvDQAHb6BSU ag8EZVJZgB5GBeabMHNlnKg== X-Received: by 2002:a17:907:1c89:b0:734:d05c:582e with SMTP id nb9-20020a1709071c8900b00734d05c582emr9323873ejc.282.1660543226544; Sun, 14 Aug 2022 23:00:26 -0700 (PDT) X-Google-Smtp-Source: AA6agR7ajggNt5I/GyHHzN8RtwufAK7sHaSR68oGYohV/XNRYX67jjVhq0Tw36JfrmGRYRVhC7SPJg== X-Received: by 2002:a17:907:1c89:b0:734:d05c:582e with SMTP id nb9-20020a1709071c8900b00734d05c582emr9323840ejc.282.1660543226308; Sun, 14 Aug 2022 23:00:26 -0700 (PDT) Received: from redhat.com ([2.54.169.49]) by smtp.gmail.com with ESMTPSA id dk19-20020a170906f0d300b0072fd1e563e2sm3743539ejb.177.2022.08.14.23.00.18 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sun, 14 Aug 2022 23:00:25 -0700 (PDT) Date: Mon, 15 Aug 2022 02:00:16 -0400 From: "Michael S. Tsirkin" To: Xuan Zhuo Cc: virtualization@lists.linux-foundation.org, Richard Weinberger , Anton Ivanov , Johannes Berg , Jason Wang , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Hans de Goede , Mark Gross , Vadim Pasternak , Bjorn Andersson , Mathieu Poirier , Cornelia Huck , Halil Pasic , Eric Farman , Heiko Carstens , Vasily Gorbik , Alexander Gordeev , Christian Borntraeger , Sven Schnelle , Alexei Starovoitov , Daniel Borkmann , Jesper Dangaard Brouer , John Fastabend , Vincent Whitchurch , linux-um@lists.infradead.org, netdev@vger.kernel.org, platform-driver-x86@vger.kernel.org, linux-remoteproc@vger.kernel.org, linux-s390@vger.kernel.org, kvm@vger.kernel.org, bpf@vger.kernel.org, kangjie.xu@linux.alibaba.com Subject: Re: [PATCH v14 37/42] virtio_net: set the default max ring size by find_vqs() Message-ID: <20220815015405-mutt-send-email-mst@kernel.org> References: <20220801063902.129329-1-xuanzhuo@linux.alibaba.com> <20220801063902.129329-38-xuanzhuo@linux.alibaba.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20220801063902.129329-38-xuanzhuo@linux.alibaba.com> Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org On Mon, Aug 01, 2022 at 02:38:57PM +0800, Xuan Zhuo wrote: > Use virtio_find_vqs_ctx_size() to specify the maximum ring size of tx, > rx at the same time. > > | rx/tx ring size > ------------------------------------------- > speed == UNKNOWN or < 10G| 1024 > speed < 40G | 4096 > speed >= 40G | 8192 > > Call virtnet_update_settings() once before calling init_vqs() to update > speed. > > Signed-off-by: Xuan Zhuo > Acked-by: Jason Wang I've been looking at this patchset because of the resent reported crashes, and I'm having second thoughts about this. Do we really want to second-guess the device supplied max ring size? If yes why? Could you please share some performance data that motivated this specific set of numbers? Also why do we intepret UNKNOWN as "very low"? I'm thinking that should definitely be "don't change anything". Finally if all this makes sense then shouldn't we react when speed changes? Could you try reverting this and showing performance results before and after please? Thanks! > --- > drivers/net/virtio_net.c | 42 ++++++++++++++++++++++++++++++++++++---- > 1 file changed, 38 insertions(+), 4 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index 8a5810bcb839..40532ecbe7fc 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -3208,6 +3208,29 @@ static unsigned int mergeable_min_buf_len(struct virtnet_info *vi, struct virtqu > (unsigned int)GOOD_PACKET_LEN); > } > > +static void virtnet_config_sizes(struct virtnet_info *vi, u32 *sizes) > +{ > + u32 i, rx_size, tx_size; > + > + if (vi->speed == SPEED_UNKNOWN || vi->speed < SPEED_10000) { > + rx_size = 1024; > + tx_size = 1024; > + > + } else if (vi->speed < SPEED_40000) { > + rx_size = 1024 * 4; > + tx_size = 1024 * 4; > + > + } else { > + rx_size = 1024 * 8; > + tx_size = 1024 * 8; > + } > + > + for (i = 0; i < vi->max_queue_pairs; i++) { > + sizes[rxq2vq(i)] = rx_size; > + sizes[txq2vq(i)] = tx_size; > + } > +} > + > static int virtnet_find_vqs(struct virtnet_info *vi) > { > vq_callback_t **callbacks; > @@ -3215,6 +3238,7 @@ static int virtnet_find_vqs(struct virtnet_info *vi) > int ret = -ENOMEM; > int i, total_vqs; > const char **names; > + u32 *sizes; > bool *ctx; > > /* We expect 1 RX virtqueue followed by 1 TX virtqueue, followed by > @@ -3242,10 +3266,15 @@ static int virtnet_find_vqs(struct virtnet_info *vi) > ctx = NULL; > } > > + sizes = kmalloc_array(total_vqs, sizeof(*sizes), GFP_KERNEL); > + if (!sizes) > + goto err_sizes; > + > /* Parameters for control virtqueue, if any */ > if (vi->has_cvq) { > callbacks[total_vqs - 1] = NULL; > names[total_vqs - 1] = "control"; > + sizes[total_vqs - 1] = 64; > } > > /* Allocate/initialize parameters for send/receive virtqueues */ > @@ -3260,8 +3289,10 @@ static int virtnet_find_vqs(struct virtnet_info *vi) > ctx[rxq2vq(i)] = true; > } > > - ret = virtio_find_vqs_ctx(vi->vdev, total_vqs, vqs, callbacks, > - names, ctx, NULL); > + virtnet_config_sizes(vi, sizes); > + > + ret = virtio_find_vqs_ctx_size(vi->vdev, total_vqs, vqs, callbacks, > + names, sizes, ctx, NULL); > if (ret) > goto err_find; > > @@ -3281,6 +3312,8 @@ static int virtnet_find_vqs(struct virtnet_info *vi) > > > err_find: > + kfree(sizes); > +err_sizes: > kfree(ctx); > err_ctx: > kfree(names); > @@ -3630,6 +3663,9 @@ static int virtnet_probe(struct virtio_device *vdev) > vi->curr_queue_pairs = num_online_cpus(); > vi->max_queue_pairs = max_queue_pairs; > > + virtnet_init_settings(dev); > + virtnet_update_settings(vi); > + > /* Allocate/initialize the rx/tx queues, and invoke find_vqs */ > err = init_vqs(vi); > if (err) > @@ -3642,8 +3678,6 @@ static int virtnet_probe(struct virtio_device *vdev) > netif_set_real_num_tx_queues(dev, vi->curr_queue_pairs); > netif_set_real_num_rx_queues(dev, vi->curr_queue_pairs); > > - virtnet_init_settings(dev); > - > if (virtio_has_feature(vdev, VIRTIO_NET_F_STANDBY)) { > vi->failover = net_failover_create(vi->dev); > if (IS_ERR(vi->failover)) { > -- > 2.31.0