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[87.10.72.39]) by smtp.gmail.com with ESMTPSA id g15sm8766816ejt.10.2021.11.16.06.33.56 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 16 Nov 2021 06:33:56 -0800 (PST) Date: Tue, 16 Nov 2021 15:33:54 +0100 From: Stefano Garzarella To: Andrey Ryabinin Cc: "Michael S. Tsirkin" , Jason Wang , Stefan Hajnoczi , kvm@vger.kernel.org, virtualization@lists.linux-foundation.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 2/6] vhost_net: get rid of vhost_net_flush_vq() and extra flush calls Message-ID: <20211116143354.exgqcjfbmmbaahs4@steredhat> References: <20211115153003.9140-1-arbn@yandex-team.com> <20211115153003.9140-2-arbn@yandex-team.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Disposition: inline In-Reply-To: <20211115153003.9140-2-arbn@yandex-team.com> Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Mon, Nov 15, 2021 at 06:29:59PM +0300, Andrey Ryabinin wrote: >vhost_net_flush_vq() calls vhost_work_dev_flush() twice passing >vhost_dev pointer obtained via 'n->poll[index].dev' and >'n->vqs[index].vq.poll.dev'. This is actually the same pointer, >initialized in vhost_net_open()/vhost_dev_init()/vhost_poll_init() > >Remove vhost_net_flush_vq() and call vhost_work_dev_flush() directly. >Do the flushes only once instead of several flush calls in a row >which seems rather useless. > >Signed-off-by: Andrey Ryabinin >--- > drivers/vhost/net.c | 11 ++--------- > drivers/vhost/vhost.h | 1 + > 2 files changed, 3 insertions(+), 9 deletions(-) > >diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c >index 11221f6d11b8..b1feb5e0571e 100644 >--- a/drivers/vhost/net.c >+++ b/drivers/vhost/net.c >@@ -1373,16 +1373,9 @@ static void vhost_net_stop(struct vhost_net *n, struct socket **tx_sock, > *rx_sock = vhost_net_stop_vq(n, &n->vqs[VHOST_NET_VQ_RX].vq); > } > >-static void vhost_net_flush_vq(struct vhost_net *n, int index) >-{ >- vhost_work_dev_flush(n->poll[index].dev); >- vhost_work_dev_flush(n->vqs[index].vq.poll.dev); >-} >- > static void vhost_net_flush(struct vhost_net *n) > { >- vhost_net_flush_vq(n, VHOST_NET_VQ_TX); >- vhost_net_flush_vq(n, VHOST_NET_VQ_RX); >+ vhost_work_dev_flush(&n->dev); > if (n->vqs[VHOST_NET_VQ_TX].ubufs) { > mutex_lock(&n->vqs[VHOST_NET_VQ_TX].vq.mutex); > n->tx_flush = true; >@@ -1572,7 +1565,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) > } > > if (oldsock) { >- vhost_net_flush_vq(n, index); >+ vhost_work_dev_flush(&n->dev); > sockfd_put(oldsock); > } > >diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h >index 638bb640d6b4..ecbaa5c6005f 100644 >--- a/drivers/vhost/vhost.h >+++ b/drivers/vhost/vhost.h >@@ -15,6 +15,7 @@ > #include > #include > >+struct vhost_dev; Is this change needed? Stefano