From mboxrd@z Thu Jan 1 00:00:00 1970 From: Maxime Coquelin Subject: Re: [PATCH 2/3] vhost: fix long stall of vhost-user negotiation Date: Mon, 23 Jan 2017 09:25:47 +0100 Message-ID: References: <1485074820-8956-1-git-send-email-yuanhan.liu@linux.intel.com> <1485074820-8956-3-git-send-email-yuanhan.liu@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: stable@dpdk.org To: Yuanhan Liu , dev@dpdk.org Return-path: In-Reply-To: <1485074820-8956-3-git-send-email-yuanhan.liu@linux.intel.com> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On 01/22/2017 09:46 AM, Yuanhan Liu wrote: > Setting up the mapping from GPA (guest physical address) to HPA (guest > physical address) could be very time consuming when the guest memory is > backened with small pages (4K). The bigger the guest memory, the longer > it takes. This could lead a very long vhost-user negotiation. > > Since the mapping is only needed in zero copy mode so far, we could > avoid such time consuming settup when zero copy is turned off (which is > the default case). > > It's actually a workaround, a right fix might be to start a new thread, > and hide the big latency there. > > Fixes: e246896178e6 ("vhost: get guest/host physical address mappings") > > Cc: stable@dpdk.org > Signed-off-by: Yuanhan Liu > --- > lib/librte_vhost/vhost_user.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) Reviewed-by: Maxime Coquelin Thanks, Maxime