From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: [PATCH 1/3] sysfs directory scaling: rbtree for dirent name lookups Date: Tue, 03 Nov 2009 23:06:14 +0100 Message-ID: <4AF0A956.5020600@gmail.com> References: <20091101163130.GA7911@kvack.org> <20091103035058.GA19515@kroah.com> <20091103200155.GQ8227@kvack.org> <20091103215650.GT8227@kvack.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "Eric W. Biederman" , Greg KH , Octavian Purdila , netdev@vger.kernel.org, Cosmin Ratiu To: Benjamin LaHaise Return-path: Received: from gw1.cosmosbay.com ([212.99.114.194]:47418 "EHLO gw1.cosmosbay.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754604AbZKCWGQ (ORCPT ); Tue, 3 Nov 2009 17:06:16 -0500 In-Reply-To: <20091103215650.GT8227@kvack.org> Sender: netdev-owner@vger.kernel.org List-ID: Benjamin LaHaise a =E9crit : > On Tue, Nov 03, 2009 at 01:43:43PM -0800, Eric W. Biederman wrote: >> I guess in particular what I would expect is that if we can do 35000 >> interfaces in 63s with an O(N^2) algorithm. Then we should be able = to >> do 35000 interfaces with an O(NlogN) algorithm in under a second. >> Which for your application should make the time essentially flat in >> the number of interfaces. >=20 > That's the wrong way to interprete the numbers. The 35000 number of = 63s is=20 > the time that it takes 63s to add 5000 more interfaces in the 30,000 = to=20 > 35,000 range. This includes the time required to add a point to poin= t ip=20 > route on the interface and bring the interface up. Speaking of pppol2tp, it seems /proc/net/pppol2tp is not safe, with a strange two phases locking... (We keep in struct pppol2tp_seq_data pointers to structures that might have been freed between to read() syscalls)