From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932686AbbJPRcI (ORCPT ); Fri, 16 Oct 2015 13:32:08 -0400 Received: from mail-pa0-f44.google.com ([209.85.220.44]:36671 "EHLO mail-pa0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932103AbbJPRcF (ORCPT ); Fri, 16 Oct 2015 13:32:05 -0400 Subject: Re: [PATCH net-next 3/4] bpf: add support for persistent maps/progs To: Hannes Frederic Sowa , Daniel Borkmann , davem@davemloft.net References: <1444991103.2861759.411876897.42C807BD@webmail.messagingengine.com> <56212366.4000307@plumgrid.com> <1445013831.2945152.412200185.4C763002@webmail.messagingengine.com> Cc: viro@ZenIV.linux.org.uk, ebiederm@xmission.com, tgraf@suug.ch, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, Alexei Starovoitov From: Alexei Starovoitov Message-ID: <56213494.9070504@plumgrid.com> Date: Fri, 16 Oct 2015 10:32:04 -0700 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.10; rv:38.0) Gecko/20100101 Thunderbird/38.3.0 MIME-Version: 1.0 In-Reply-To: <1445013831.2945152.412200185.4C763002@webmail.messagingengine.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 10/16/15 9:43 AM, Hannes Frederic Sowa wrote: > Hi Alexei, > > On Fri, Oct 16, 2015, at 18:18, Alexei Starovoitov wrote: >> On 10/16/15 3:25 AM, Hannes Frederic Sowa wrote: >>> Namespaces at some point dealt with the same problem, they nowadays use >>> bind mounts of/proc/$$/ns/* to some place in the file hierarchy to keep >>> the namespace alive. This at least allows someone to build up its own >>> hierarchy with normal unix tools and not hidden inside a C-program. For >>> filedescriptors we already have/proc/$$/fd/* but it seems that doesn't >>> work out of the box nowadays. >> >> bind mounting of /proc/../fd was initially proposed by Andy and we've >> looked at it thoroughly, but after discussion with Eric it became >> apparent that it doesn't fit here. At the end we need shell tools >> to access maps. > > Oh yes, I want shell tools for this very much! Maybe even that things > like strings, grep etc. work. :) yes and the only way to get there is to have it done via fs. >> Also I think you missed the hierarchy in this patch set _is_ built with >> normal 'mkdir' and files are removed with 'rm'. > > I did not miss that, I am just concerned that if the kernel does not > enforce such a hierarchy automatically it won't really happen. if it's easier for user to work with single level of directories, it should be able to do so. It's not a job of the kernel to enforce how user space apps should be designed. > Oh, tracing does not allow daemons. Why? I can only imagine embedded > users, no? yes and for networking: restartability and HA. cannot really do that with fuse/daemons.