From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH v9 net-next 5/7] net: simple poll/select low latency socket poll Date: Wed, 05 Jun 2013 08:20:06 -0700 Message-ID: <1370445606.24311.265.camel@edumazet-glaptop> References: <20130605103400.11172.49099.stgit@ladj378.jer.intel.com> <20130605103452.11172.31453.stgit@ladj378.jer.intel.com> <1370439054.24311.248.camel@edumazet-glaptop> <51AF401C.2030506@linux.intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Cc: Willem de Bruijn , Don, Or Gerlitz , e1000-devel@lists.sourceforge.net, netdev@vger.kernel.org, HPA , Amir Vadai , Jesse Brandeburg , Eliezer Tamir , linux-kernel@vger.kernel.org, Andi Kleen , Ben Hutchings , Eilon Greenstien , David Miller To: Eliezer Tamir Return-path: In-Reply-To: <51AF401C.2030506@linux.intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: e1000-devel-bounces@lists.sourceforge.net List-Id: netdev.vger.kernel.org On Wed, 2013-06-05 at 16:41 +0300, Eliezer Tamir wrote: > On 05/06/2013 16:30, Eric Dumazet wrote: > > I am a bit uneasy with this one, because an applicatio polling() on one > > thousand file descriptors using select()/poll(), will call sk_poll_ll() > > one thousand times. > > But we call sk_poll_ll() with nonblock set, so it will only test once > for each socket and not loop. > > I think this is not as bad as it sounds. > We still honor the time limit on how long to poll. We still call ndo_ll_poll() a thousand times, and probably do a spinlock/unlock a thousand times in the driver. I would definitely be convinced if you give us some performance numbers of a poll() on a thousand tcp sockets for example. See my following mail about sk_poll_ll() ------------------------------------------------------------------------------ How ServiceNow helps IT people transform IT departments: 1. A cloud service to automate IT design, transition and operations 2. Dashboards that offer high-level views of enterprise services 3. A single system of record for all IT processes http://p.sf.net/sfu/servicenow-d2d-j _______________________________________________ E1000-devel mailing list E1000-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/e1000-devel To learn more about Intel® Ethernet, visit http://communities.intel.com/community/wired