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 X-Spam-Level: X-Spam-Status: No, score=-6.8 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7CF8BC3A5A1 for ; Thu, 22 Aug 2019 17:43:51 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 4674623400 for ; Thu, 22 Aug 2019 17:43:51 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566495831; bh=JoL/hk8uL4jNEVsyss976KBKorebOwKO0xejjgDHb4U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=ekqgvgPN4qqvQ7pTIxkI7ArNcaEK7Cwc8Gz4H/rEpaCO6dX1tV/VNyWRlxxFkf1Yo fZ/zodj0UvDO3Lj/JkPPYJoGTxQJ/6WMQKwbEN6KTE6A93NI1Y0csupIYt5SI0WbhZ hLjEU+zHwaCQcAOJeQeqWN9P/qLJ+BfUOTJQRL2Y= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388723AbfHVRnu (ORCPT ); Thu, 22 Aug 2019 13:43:50 -0400 Received: from mail.kernel.org ([198.145.29.99]:44058 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2403992AbfHVRXm (ORCPT ); Thu, 22 Aug 2019 13:23:42 -0400 Received: from localhost (wsip-184-188-36-2.sd.sd.cox.net [184.188.36.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 8AF8923439; Thu, 22 Aug 2019 17:23:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1566494621; bh=JoL/hk8uL4jNEVsyss976KBKorebOwKO0xejjgDHb4U=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=sTWr0manMOj7ccljVi7sVp9D5yhJiZHCYcZNX3ORd78vzGJWcgUu/9ymhkv6EqFgx e2ZMox87qD1b8R+sSXh9tF+GZMfh8mtl4EJ0wqC5X6sQN5J7JG4NR8jAqX3bB/2bwm fKViMhvy0W+0VGqXmh0na19rCzXd+mf0MmnE/p6Y= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Jason Wang , Stefan Hajnoczi , "Michael S. Tsirkin" , Ben Hutchings Subject: [PATCH 4.9 051/103] vhost: introduce vhost_exceeds_weight() Date: Thu, 22 Aug 2019 10:18:39 -0700 Message-Id: <20190822171730.868050037@linuxfoundation.org> X-Mailer: git-send-email 2.23.0 In-Reply-To: <20190822171728.445189830@linuxfoundation.org> References: <20190822171728.445189830@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Jason Wang commit e82b9b0727ff6d665fff2d326162b460dded554d upstream. We used to have vhost_exceeds_weight() for vhost-net to: - prevent vhost kthread from hogging the cpu - balance the time spent between TX and RX This function could be useful for vsock and scsi as well. So move it to vhost.c. Device must specify a weight which counts the number of requests, or it can also specific a byte_weight which counts the number of bytes that has been processed. Signed-off-by: Jason Wang Reviewed-by: Stefan Hajnoczi Signed-off-by: Michael S. Tsirkin [bwh: Backported to 4.9: - In vhost_net, both Tx modes are handled in one loop in handle_tx() - Adjust context] Signed-off-by: Ben Hutchings Signed-off-by: Greg Kroah-Hartman --- drivers/vhost/net.c | 18 +++++------------- drivers/vhost/scsi.c | 9 ++++++++- drivers/vhost/vhost.c | 20 +++++++++++++++++++- drivers/vhost/vhost.h | 6 +++++- drivers/vhost/vsock.c | 12 +++++++++++- 5 files changed, 48 insertions(+), 17 deletions(-) --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -357,12 +357,6 @@ static int vhost_net_tx_get_vq_desc(stru return r; } -static bool vhost_exceeds_weight(int pkts, int total_len) -{ - return total_len >= VHOST_NET_WEIGHT || - pkts >= VHOST_NET_PKT_WEIGHT; -} - /* Expects to be always run from workqueue - which acts as * read-size critical section for our kind of RCU. */ static void handle_tx(struct vhost_net *net) @@ -487,10 +481,9 @@ static void handle_tx(struct vhost_net * vhost_zerocopy_signal_used(net, vq); total_len += len; vhost_net_tx_packet(net); - if (unlikely(vhost_exceeds_weight(++sent_pkts, total_len))) { - vhost_poll_queue(&vq->poll); + if (unlikely(vhost_exceeds_weight(vq, ++sent_pkts, + total_len))) break; - } } out: mutex_unlock(&vq->mutex); @@ -768,10 +761,8 @@ static void handle_rx(struct vhost_net * vhost_log_write(vq, vq_log, log, vhost_len, vq->iov, in); total_len += vhost_len; - if (unlikely(vhost_exceeds_weight(++recv_pkts, total_len))) { - vhost_poll_queue(&vq->poll); + if (unlikely(vhost_exceeds_weight(vq, ++recv_pkts, total_len))) goto out; - } } vhost_net_enable_vq(net, vq); out: @@ -842,7 +833,8 @@ static int vhost_net_open(struct inode * n->vqs[i].vhost_hlen = 0; n->vqs[i].sock_hlen = 0; } - vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX); + vhost_dev_init(dev, vqs, VHOST_NET_VQ_MAX, + VHOST_NET_WEIGHT, VHOST_NET_PKT_WEIGHT); vhost_poll_init(n->poll + VHOST_NET_VQ_TX, handle_tx_net, POLLOUT, dev); vhost_poll_init(n->poll + VHOST_NET_VQ_RX, handle_rx_net, POLLIN, dev); --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -58,6 +58,12 @@ #define VHOST_SCSI_PREALLOC_UPAGES 2048 #define VHOST_SCSI_PREALLOC_PROT_SGLS 512 +/* Max number of requests before requeueing the job. + * Using this limit prevents one virtqueue from starving others with + * request. + */ +#define VHOST_SCSI_WEIGHT 256 + struct vhost_scsi_inflight { /* Wait for the flush operation to finish */ struct completion comp; @@ -1433,7 +1439,8 @@ static int vhost_scsi_open(struct inode vqs[i] = &vs->vqs[i].vq; vs->vqs[i].vq.handle_kick = vhost_scsi_handle_kick; } - vhost_dev_init(&vs->dev, vqs, VHOST_SCSI_MAX_VQ); + vhost_dev_init(&vs->dev, vqs, VHOST_SCSI_MAX_VQ, + VHOST_SCSI_WEIGHT, 0); vhost_scsi_init_inflight(vs, NULL); --- a/drivers/vhost/vhost.c +++ b/drivers/vhost/vhost.c @@ -393,8 +393,24 @@ static void vhost_dev_free_iovecs(struct vhost_vq_free_iovecs(dev->vqs[i]); } +bool vhost_exceeds_weight(struct vhost_virtqueue *vq, + int pkts, int total_len) +{ + struct vhost_dev *dev = vq->dev; + + if ((dev->byte_weight && total_len >= dev->byte_weight) || + pkts >= dev->weight) { + vhost_poll_queue(&vq->poll); + return true; + } + + return false; +} +EXPORT_SYMBOL_GPL(vhost_exceeds_weight); + void vhost_dev_init(struct vhost_dev *dev, - struct vhost_virtqueue **vqs, int nvqs) + struct vhost_virtqueue **vqs, int nvqs, + int weight, int byte_weight) { struct vhost_virtqueue *vq; int i; @@ -408,6 +424,8 @@ void vhost_dev_init(struct vhost_dev *de dev->iotlb = NULL; dev->mm = NULL; dev->worker = NULL; + dev->weight = weight; + dev->byte_weight = byte_weight; init_llist_head(&dev->work_list); init_waitqueue_head(&dev->wait); INIT_LIST_HEAD(&dev->read_list); --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -164,9 +164,13 @@ struct vhost_dev { struct list_head read_list; struct list_head pending_list; wait_queue_head_t wait; + int weight; + int byte_weight; }; -void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, int nvqs); +bool vhost_exceeds_weight(struct vhost_virtqueue *vq, int pkts, int total_len); +void vhost_dev_init(struct vhost_dev *, struct vhost_virtqueue **vqs, + int nvqs, int weight, int byte_weight); long vhost_dev_set_owner(struct vhost_dev *dev); bool vhost_dev_has_owner(struct vhost_dev *dev); long vhost_dev_check_owner(struct vhost_dev *); --- a/drivers/vhost/vsock.c +++ b/drivers/vhost/vsock.c @@ -21,6 +21,14 @@ #include "vhost.h" #define VHOST_VSOCK_DEFAULT_HOST_CID 2 +/* Max number of bytes transferred before requeueing the job. + * Using this limit prevents one virtqueue from starving others. */ +#define VHOST_VSOCK_WEIGHT 0x80000 +/* Max number of packets transferred before requeueing the job. + * Using this limit prevents one virtqueue from starving others with + * small pkts. + */ +#define VHOST_VSOCK_PKT_WEIGHT 256 enum { VHOST_VSOCK_FEATURES = VHOST_FEATURES, @@ -529,7 +537,9 @@ static int vhost_vsock_dev_open(struct i vsock->vqs[VSOCK_VQ_TX].handle_kick = vhost_vsock_handle_tx_kick; vsock->vqs[VSOCK_VQ_RX].handle_kick = vhost_vsock_handle_rx_kick; - vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs)); + vhost_dev_init(&vsock->dev, vqs, ARRAY_SIZE(vsock->vqs), + VHOST_VSOCK_PKT_WEIGHT, + VHOST_VSOCK_WEIGHT); file->private_data = vsock; spin_lock_init(&vsock->send_pkt_list_lock);