Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755887Ab3FEOAN (ORCPT ); Wed, 5 Jun 2013 10:00:13 -0400 Received: from mail-pb0-f52.google.com ([209.85.160.52]:41637 "EHLO mail-pb0-f52.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753097Ab3FEOAL (ORCPT ); Wed, 5 Jun 2013 10:00:11 -0400 Message-ID: <1370440808.24311.254.camel@edumazet-glaptop> Subject: RE: [PATCH v9 net-next 5/7] net: simple poll/select low latency socket poll From: Eric Dumazet To: David Laight Cc: Eliezer Tamir , David Miller , linux-kernel@vger.kernel.org, netdev@vger.kernel.org, Jesse Brandeburg , Don Skidmore , e1000-devel@lists.sourceforge.net, Willem de Bruijn , Ben Hutchings , Andi Kleen , HPA , Eilon Greenstien , Or Gerlitz , Amir Vadai , Eliezer Tamir Date: Wed, 05 Jun 2013 07:00:08 -0700 In-Reply-To: References: <20130605103400.11172.49099.stgit@ladj378.jer.intel.com> <20130605103452.11172.31453.stgit@ladj378.jer.intel.com> <1370439054.24311.248.camel@edumazet-glaptop> Content-Type: text/plain; charset="UTF-8" X-Mailer: Evolution 3.2.3-0ubuntu6 Content-Transfer-Encoding: 7bit Mime-Version: 1.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 894 Lines: 23 On Wed, 2013-06-05 at 14:49 +0100, David Laight 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. > > Anything calling poll() on 1000 fds probably has performance > issues already! Which is why kevent schemes have been added. > You'll be surprised but many applications still use poll(), and not epoll() or whatever OS specific interface, because they are non portable or buggy. (I played with FreeBSD and kevent crashed easily at 64,000 fds, while the epoll() version reached 4,000,000 fds with no problems) -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/