From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751305Ab1AVGhh (ORCPT ); Sat, 22 Jan 2011 01:37:37 -0500 Received: from web63902.mail.re1.yahoo.com ([69.147.97.117]:43052 "HELO web63902.mail.re1.yahoo.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1751139Ab1AVGhg (ORCPT ); Sat, 22 Jan 2011 01:37:36 -0500 X-Greylist: delayed 400 seconds by postgrey-1.27 at vger.kernel.org; Sat, 22 Jan 2011 01:37:36 EST DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:Cc:MIME-Version:Content-Type; b=2Ci5PT1xbjWbroFDYAtLblRXYLPLtt46Mti3kpeAabCnJcOYW+x3Z4rdapLXkbuE1TwfSDCs2ReP8uEF+Ku+UtzlDrSMRllRxiestkkz8hnTqOeOAk4pLrCh3Zh2yARbcQ9gujohT9RNqmbtVSqpl34Y1VeVeXREzfqxUNR/ybs=; Message-ID: <702550.61465.qm@web63902.mail.re1.yahoo.com> X-YMail-OSG: W7Vv7LQVM1kTQ2jXspJ2ssTgI69eo.RchdcSXKUE_fWurF9 _dl3HnwRiTK6XU6PdVVM.R8NZvaLPu8QLrnUCIWgp56FZ.WXK8vpjtLPBX5e RkK1XlDl1j7UwjSubIog.2bexKI7YwoeK__41NDtuCsMtUy.T.8gm1etHCyw U9a.jWLDkZvFuJSb9LucZfOpgPAQv0IBnO9M4.LjfGiYFeb4EshfeTLjUk7X qSp7_dlkhb.c4Iz1I4Pb92xyMoSRd7.E1OpaTdactXAubtPHfuHGXAmJUgs4 w83L4SrFQtNPCmOMRhyOGD_g2yh_909pXepXgjN4eC5HJaNrw7yU- X-Mailer: YahooMailRC/555 YahooMailWebService/0.8.107.285259 Date: Fri, 21 Jan 2011 22:30:54 -0800 (PST) From: PK Subject: Problems with /proc/net/tcp6 - possible bug - ipv6 To: linux-kernel@vger.kernel.org Cc: runningdoglackey@yahoo.com MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Creating many ipv6 connections hits a ceiling on connections/fds ; okay, fine. But in my case I'm seeing millions of entries spring up within a few seconds and then vanish within a few minutes, in /proc/net/tcp6 (vanish due to garbage collection?) Furthermore I can trigger this easily on vanilla kernels from 2.6.36 to 2.6.38-rc1-next-20110121 inside a ubuntu 10.10 amd64 vm, causing the kernel to spew warnings. There is also some corruption in the logs (see kernel-sample.log line 296), but that may be unrelated. More explanation, kernel config of the primary machine I saw this on, sample ruby script to reproduce (inside the ubuntu VMs I apt-get and use ruby-1.9.1), are located at https://github.com/runningdogx/net6-bug Seems to only affect 64-bit. So far I have not been able to reproduce on 32-bit ubuntu VMs of any kernel version. Seems to only affect IPv6. So far I have not been able to reproduce using IPv4 connections (and watching /proc/net/tcp of course). Does not trigger the bug if the connections are made to ::1. Only externally routable local and global IPv6 addresses seem to cause problems. Seems to have been introduced between 2.6.35 and 2.6.36 (see README on github for more kernels I've tried) All the tested Ubuntu VMs are stock 10.10 userland, with vanilla kernels (the latest ubuntu kernel is 2.6.35-something, and my initial test didn't show it suffering from this problem) Originally noticed on separate Gentoo 64-bit non-vm system when doing web benchmarking. not subscribed, so please keep me in cc although I'll try to follow the thread