From mboxrd@z Thu Jan 1 00:00:00 1970 From: "K. Y. Srinivasan" Subject: [PATCH 3/4] Staging: hv: vmbus: Check for events before messages Date: Wed, 31 Aug 2011 14:35:56 -0700 Message-ID: <1314826557-28755-3-git-send-email-kys@microsoft.com> References: <1314826529-28716-1-git-send-email-kys@microsoft.com> <1314826557-28755-1-git-send-email-kys@microsoft.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <1314826557-28755-1-git-send-email-kys@microsoft.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: devel-bounces@linuxdriverproject.org Sender: devel-bounces@linuxdriverproject.org To: gregkh@suse.de, linux-kernel@vger.kernel.org, devel@linuxdriverproject.org, virtualization@lists.osdl.org Cc: Haiyang Zhang List-Id: virtualization@lists.linuxfoundation.org The Windows team has informed us that on Windows guests on Hyper-V, they check for events before messages. They also recommended that we do the same. This patch addresses this. Signed-off-by: K. Y. Srinivasan Signed-off-by: Haiyang Zhang --- drivers/staging/hv/vmbus_drv.c | 22 ++++++++++++++-------- 1 files changed, 14 insertions(+), 8 deletions(-) diff --git a/drivers/staging/hv/vmbus_drv.c b/drivers/staging/hv/vmbus_drv.c index b5e06d6..cd43ddd 100644 --- a/drivers/staging/hv/vmbus_drv.c +++ b/drivers/staging/hv/vmbus_drv.c @@ -442,14 +442,11 @@ static irqreturn_t vmbus_isr(int irq, void *dev_id) union hv_synic_event_flags *event; bool handled = false; - page_addr = hv_context.synic_message_page[cpu]; - msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT; - - /* Check if there are actual msgs to be process */ - if (msg->header.message_type != HVMSG_NONE) { - handled = true; - tasklet_schedule(&msg_dpc); - } + /* + * Check for events before checking for messages. This is the order + * in which events and messages are checked in Windows guests on + * Hyper-V, and the Windows team suggested we do the same. + */ page_addr = hv_context.synic_event_page[cpu]; event = (union hv_synic_event_flags *)page_addr + VMBUS_MESSAGE_SINT; @@ -460,6 +457,15 @@ static irqreturn_t vmbus_isr(int irq, void *dev_id) tasklet_schedule(&event_dpc); } + page_addr = hv_context.synic_message_page[cpu]; + msg = (struct hv_message *)page_addr + VMBUS_MESSAGE_SINT; + + /* Check if there are actual msgs to be processed */ + if (msg->header.message_type != HVMSG_NONE) { + handled = true; + tasklet_schedule(&msg_dpc); + } + if (handled) return IRQ_HANDLED; else -- 1.7.4.1