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 AAA1DC4167B for ; Thu, 14 Dec 2023 10:24:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1443624AbjLNKYq (ORCPT ); Thu, 14 Dec 2023 05:24:46 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55038 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1443617AbjLNKYo (ORCPT ); Thu, 14 Dec 2023 05:24:44 -0500 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id C9160E0 for ; Thu, 14 Dec 2023 02:24:50 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1702549490; 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=DSSH8LtzM2s/nHi8p5P1p50CtgKbNQDA/Xelk2DiA14=; b=HP4qSm2La8BFs5PuUsColw3oP1quGz6AGYQ2aYJlpJh2PJBuWU4OEaP/TRKryl0BZUkVdh BhIGb9+vW1f0Po2UKHiR2q++2nBFC73oqXJ9M2J2Dar2rWqfQK7B4BIdnkC0vJzF1kMYi3 jriaGF59wNIiRKOPqnJNI9AllVvHl3g= Received: from mail-ej1-f72.google.com (mail-ej1-f72.google.com [209.85.218.72]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-66-LALcHKd5N0Cj6DGEm-krGw-1; Thu, 14 Dec 2023 05:24:46 -0500 X-MC-Unique: LALcHKd5N0Cj6DGEm-krGw-1 Received: by mail-ej1-f72.google.com with SMTP id a640c23a62f3a-a1f99dd182dso260860666b.3 for ; Thu, 14 Dec 2023 02:24:46 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1702549485; x=1703154285; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=DSSH8LtzM2s/nHi8p5P1p50CtgKbNQDA/Xelk2DiA14=; b=UhMp65D4TbWdOMbFcPR2M9oxF7kNPSBEKpxJscpShfSf0GoZQH7mMd7clSDRa10n3c 2yK1JNz43s2UjguW8R1sbVjySHOVUblqdX6Z39b3uwduQw6ptoMUsV0FLwyvw0lDk2Y7 arBSfd/yYSlB4wdspVrSWLPkPgu4St5tWxA9YToFwTJUBErAx6V4j0jDtxFKCgafz5WL tT6oi60yviqSSk+XjOMx1qLBAtCChUI8mhNvNJRN6M1XAd06CNYy/UtxTW4q5Gs2WcRz 0wrE4fPjON3QQRRlKtmZjVutOX5DyXFVef/t5BKbEPKNHNbsMz6DwqlIqML9GgWS1nil cPrQ== X-Gm-Message-State: AOJu0YxLlsy18utjuz9tGnzipH/69YltICo7cxvayAJGlcjdMsaNi5Dc UW48j2ACRvUBP2pW3WY/iTBlpP1atpVPCF6ch7keSQdQ/AvXEANEFjAwH7+/6ZW5csiwGUkj6TX SaQYS1LFkCI+Li731uS7t+/Fg X-Received: by 2002:a17:907:3a97:b0:a1f:7352:3c0 with SMTP id fh23-20020a1709073a9700b00a1f735203c0mr4111140ejc.59.1702549485733; Thu, 14 Dec 2023 02:24:45 -0800 (PST) X-Google-Smtp-Source: AGHT+IFJ4mtbeRMe02kWwF6Hh+xBcu1mR/wHuPokTQ+4Rni40u2pBzA16VxW6ly8OowEf1SbmDDVig== X-Received: by 2002:a17:907:3a97:b0:a1f:7352:3c0 with SMTP id fh23-20020a1709073a9700b00a1f735203c0mr4111122ejc.59.1702549485320; Thu, 14 Dec 2023 02:24:45 -0800 (PST) Received: from redhat.com ([2.52.132.243]) by smtp.gmail.com with ESMTPSA id vv6-20020a170907a68600b00a1dff479037sm9103575ejc.127.2023.12.14.02.24.42 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 14 Dec 2023 02:24:44 -0800 (PST) Date: Thu, 14 Dec 2023 05:24:40 -0500 From: "Michael S. Tsirkin" To: Arseniy Krasnov Cc: Stefan Hajnoczi , Stefano Garzarella , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Jason Wang , Bobby Eshleman , kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, kernel@sberdevices.ru, oxffffaa@gmail.com Subject: Re: [PATCH net-next v9 2/4] virtio/vsock: send credit update during setting SO_RCVLOWAT Message-ID: <20231214052234-mutt-send-email-mst@kernel.org> References: <20231214091947.395892-1-avkrasnov@salutedevices.com> <20231214091947.395892-3-avkrasnov@salutedevices.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20231214091947.395892-3-avkrasnov@salutedevices.com> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Dec 14, 2023 at 12:19:45PM +0300, Arseniy Krasnov wrote: > Send credit update message when SO_RCVLOWAT is updated and it is bigger > than number of bytes in rx queue. It is needed, because 'poll()' will > wait until number of bytes in rx queue will be not smaller than > SO_RCVLOWAT, so kick sender to send more data. Otherwise mutual hungup > for tx/rx is possible: sender waits for free space and receiver is > waiting data in 'poll()'. > > Fixes: b89d882dc9fc ("vsock/virtio: reduce credit update messages") > Signed-off-by: Arseniy Krasnov > Reviewed-by: Stefano Garzarella > Acked-by: Michael S. Tsirkin > --- > Changelog: > v1 -> v2: > * Update commit message by removing 'This patch adds XXX' manner. > * Do not initialize 'send_update' variable - set it directly during > first usage. > v3 -> v4: > * Fit comment in 'virtio_transport_notify_set_rcvlowat()' to 80 chars. > v4 -> v5: > * Do not change callbacks order in transport structures. > v5 -> v6: > * Reorder callbacks in transport structures. > * Do to send credit update when 'fwd_cnt' == 'last_fwd_cnt'. > v8 -> v9: > * Add 'Fixes' tag. > > drivers/vhost/vsock.c | 1 + > include/linux/virtio_vsock.h | 1 + > net/vmw_vsock/virtio_transport.c | 1 + > net/vmw_vsock/virtio_transport_common.c | 30 +++++++++++++++++++++++++ > net/vmw_vsock/vsock_loopback.c | 1 + > 5 files changed, 34 insertions(+) > > diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c > index f75731396b7e..ec20ecff85c7 100644 > --- a/drivers/vhost/vsock.c > +++ b/drivers/vhost/vsock.c > @@ -449,6 +449,7 @@ static struct virtio_transport vhost_transport = { > .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue, > .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue, > .notify_buffer_size = virtio_transport_notify_buffer_size, > + .notify_set_rcvlowat = virtio_transport_notify_set_rcvlowat, > This needs to be set_rcvlowat. > .read_skb = virtio_transport_read_skb, > }, > diff --git a/include/linux/virtio_vsock.h b/include/linux/virtio_vsock.h > index ebb3ce63d64d..c82089dee0c8 100644 > --- a/include/linux/virtio_vsock.h > +++ b/include/linux/virtio_vsock.h > @@ -256,4 +256,5 @@ void virtio_transport_put_credit(struct virtio_vsock_sock *vvs, u32 credit); > void virtio_transport_deliver_tap_pkt(struct sk_buff *skb); > int virtio_transport_purge_skbs(void *vsk, struct sk_buff_head *list); > int virtio_transport_read_skb(struct vsock_sock *vsk, skb_read_actor_t read_actor); > +int virtio_transport_notify_set_rcvlowat(struct vsock_sock *vsk, int val); > #endif /* _LINUX_VIRTIO_VSOCK_H */ > diff --git a/net/vmw_vsock/virtio_transport.c b/net/vmw_vsock/virtio_transport.c > index af5bab1acee1..f495b9e5186b 100644 > --- a/net/vmw_vsock/virtio_transport.c > +++ b/net/vmw_vsock/virtio_transport.c > @@ -537,6 +537,7 @@ static struct virtio_transport virtio_transport = { > .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue, > .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue, > .notify_buffer_size = virtio_transport_notify_buffer_size, > + .notify_set_rcvlowat = virtio_transport_notify_set_rcvlowat, > > .read_skb = virtio_transport_read_skb, > }, This, too. > diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c > index 7eabe5219ef7..9d2305fdc65c 100644 > --- a/net/vmw_vsock/virtio_transport_common.c > +++ b/net/vmw_vsock/virtio_transport_common.c > @@ -1690,6 +1690,36 @@ int virtio_transport_read_skb(struct vsock_sock *vsk, skb_read_actor_t recv_acto > } > EXPORT_SYMBOL_GPL(virtio_transport_read_skb); > > +int virtio_transport_notify_set_rcvlowat(struct vsock_sock *vsk, int val) > +{ > + struct virtio_vsock_sock *vvs = vsk->trans; > + bool send_update; > + > + spin_lock_bh(&vvs->rx_lock); > + > + /* If number of available bytes is less than new SO_RCVLOWAT value, > + * kick sender to send more data, because sender may sleep in its > + * 'send()' syscall waiting for enough space at our side. Also > + * don't send credit update when peer already knows actual value - > + * such transmission will be useless. > + */ > + send_update = (vvs->rx_bytes < val) && > + (vvs->fwd_cnt != vvs->last_fwd_cnt); > + > + spin_unlock_bh(&vvs->rx_lock); > + > + if (send_update) { > + int err; > + > + err = virtio_transport_send_credit_update(vsk); > + if (err < 0) > + return err; > + } > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(virtio_transport_notify_set_rcvlowat); > + > MODULE_LICENSE("GPL v2"); > MODULE_AUTHOR("Asias He"); > MODULE_DESCRIPTION("common code for virtio vsock"); I think you need to set sk->sk_rcvlowat here, no? Follow up patch will move it to transport independent code. > diff --git a/net/vmw_vsock/vsock_loopback.c b/net/vmw_vsock/vsock_loopback.c > index 048640167411..6dea6119f5b2 100644 > --- a/net/vmw_vsock/vsock_loopback.c > +++ b/net/vmw_vsock/vsock_loopback.c > @@ -96,6 +96,7 @@ static struct virtio_transport loopback_transport = { > .notify_send_pre_enqueue = virtio_transport_notify_send_pre_enqueue, > .notify_send_post_enqueue = virtio_transport_notify_send_post_enqueue, > .notify_buffer_size = virtio_transport_notify_buffer_size, > + .notify_set_rcvlowat = virtio_transport_notify_set_rcvlowat, > > .read_skb = virtio_transport_read_skb, > }, > -- > 2.25.1