From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752248AbaDDIeZ (ORCPT ); Fri, 4 Apr 2014 04:34:25 -0400 Received: from fep21.mx.upcmail.net ([62.179.121.41]:34857 "EHLO fep21.mx.upcmail.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751899AbaDDIeS (ORCPT ); Fri, 4 Apr 2014 04:34:18 -0400 X-SourceIP: 2001:470:25:65c::2 X-Authenticated-Sender: odi.ch@hispeed.ch Message-ID: <533E6E83.7030106@odi.ch> Date: Fri, 04 Apr 2014 10:34:11 +0200 From: =?UTF-8?B?T3J0d2luIEdsw7xjaw==?= User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:24.0) Gecko/20100101 Thunderbird/24.4.0 MIME-Version: 1.0 To: Eric Dumazet CC: linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: 3.14 regression: huge latency in read/select on tun References: <533C381E.9090103@odi.ch> <1396456973.3989.41.camel@edumazet-glaptop2.roam.corp.google.com> <533D133A.3090008@odi.ch> <1396531176.12330.6.camel@edumazet-glaptop2.roam.corp.google.com> <1396533026.12330.9.camel@edumazet-glaptop2.roam.corp.google.com> In-Reply-To: <1396533026.12330.9.camel@edumazet-glaptop2.roam.corp.google.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 03.04.2014 15:50, Eric Dumazet wrote: > If bug is in tun.c you have this list of changes you could bisect > from : > > # git log --oneline v3.13..v3.14 drivers/net/tun.c > 6671b2240c54 tun: remove bogus hardware vlan acceleration flags from vlan_features > 99932d4fc03a netdevice: add queue selection fallback handler for ndo_select_queue > 93e14b6d776e tun: add device name(iff) field to proc fdinfo entry > fa35864e0bb7 tuntap: Fix for a race in accessing numqueues > 0a379e21c503 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net > fbe4d4565bad tun, rfs: fix the incorrect hash value > 9bc8893937c8 tun: Add support for RFS on tun flows > 143c90549494 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net > 3958afa1b272 net: Change skb_get_rxhash to skb_get_hash > 42404c091510 Revert "tun: remove useless codes in tun_chr_aio_read() and tun_recvmsg()" > 73713357ab58 tun: remove useless codes in tun_chr_aio_read() and tun_recvmsg() > 34f9f437104b Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net > f96eb74c84eb tun: remove unused parameter in tun_do_read() > 92d4ea6e412a tun: spelling fixes That list doesn't look too promising. I'd rather look in net/ipv4 which does have TSO/GSO related changes. I tried to bisect that but the system hangs on boot when net devices are enabled. So it may prove difficult to pin down. I may try again during the weekend.