From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: [PATCH net-next v3 7/7] netvsc: signal host if receive ring is emptied Date: Fri, 28 Jul 2017 08:59:47 -0700 Message-ID: <20170728155947.10062-8-sthemmin@microsoft.com> References: <20170728155947.10062-1-sthemmin@microsoft.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: devel@linuxdriverproject.org, netdev@vger.kernel.org To: kys@microsoft.com, haiyangz@microsoft.com, sthemmin@microsoft.com Return-path: In-Reply-To: <20170728155947.10062-1-sthemmin@microsoft.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: driverdev-devel-bounces@linuxdriverproject.org Sender: "devel" List-Id: netdev.vger.kernel.org Latency improvement related to NAPI conversion. If all packets are processed from receive ring then need to signal host. Signed-off-by: Stephen Hemminger --- drivers/net/hyperv/netvsc.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) diff --git a/drivers/net/hyperv/netvsc.c b/drivers/net/hyperv/netvsc.c index db95487807fd..c64934c64dca 100644 --- a/drivers/net/hyperv/netvsc.c +++ b/drivers/net/hyperv/netvsc.c @@ -1195,10 +1195,15 @@ int netvsc_poll(struct napi_struct *napi, int budget) nvchan->desc = hv_pkt_iter_next(channel, nvchan->desc); } - /* If send of pending receive completions suceeded - * and did not exhaust NAPI budget + /* if ring is empty, signal host */ + if (!nvchan->desc) + hv_pkt_iter_close(channel); + + /* If send of pending receive completions suceeded + * and did not exhaust NAPI budget this time * and not doing busy poll - * then reschedule if more data has arrived from host + * then re-enable host interrupts + * and reschedule if ring is not empty. */ if (send_recv_completions(nvchan) == 0 && work_done < budget && -- 2.11.0