From mboxrd@z Thu Jan 1 00:00:00 1970 From: Richard Weinberger Subject: Re: [PATCH 1/2v6] procfs: show hierarchy of pid namespace Date: Thu, 06 Nov 2014 09:13:56 +0100 Message-ID: <545B2DC4.1090005@nod.at> References: <1415184115-12022-1-git-send-email-chenhanxiao@cn.fujitsu.com> <1415184115-12022-2-git-send-email-chenhanxiao@cn.fujitsu.com> <545A13DA.3090207@nod.at> <20141105124111.GA19563@mail.hallyn.com> <545A1D53.3070507@nod.at> <5871495633F38949900D2BF2DC04883E61F2B2@G08CNEXMBPEKD02.g08.fujitsu.local> Mime-Version: 1.0 Content-Type: text/plain; charset="gbk" Content-Transfer-Encoding: base64 Return-path: In-Reply-To: <5871495633F38949900D2BF2DC04883E61F2B2-ZEd+hNNJ6a5ZYpXjqAkB5jz3u5zwRJJDAzI0kPv9QBlmR6Xm/wNWPw@public.gmane.org> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org Errors-To: containers-bounces-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org To: "Chen, Hanxiao" , "Serge E. Hallyn" Cc: "containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org" , Serge Hallyn , "linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , Mateusz Guzik , David Howells , "Eric W. Biederman" , Oleg Nesterov List-Id: containers.vger.kernel.org QW0gMDYuMTEuMjAxNCB1bSAwNjo0OCBzY2hyaWViIENoZW4sIEhhbnhpYW86Cj4gCj4gCj4+IC0t LS0tT3JpZ2luYWwgTWVzc2FnZS0tLS0tCj4+IEZyb206IFJpY2hhcmQgV2VpbmJlcmdlciBbbWFp bHRvOnJpY2hhcmRAbm9kLmF0XQo+PiBTZW50OiBXZWRuZXNkYXksIE5vdmVtYmVyIDA1LCAyMDE0 IDg6NTIgUE0KPj4gVG86IFNlcmdlIEUuIEhhbGx5bgo+PiBDYzogQ2hlbiwgSGFueGlhby+zwiDq z8/2OyBFcmljIFcuIEJpZWRlcm1hbjsgU2VyZ2UgSGFsbHluOyBPbGVnIE5lc3Rlcm92Owo+PiBj b250YWluZXJzQGxpc3RzLmxpbnV4LWZvdW5kYXRpb24ub3JnOyBsaW51eC1rZXJuZWxAdmdlci5r ZXJuZWwub3JnOyBNYXRldXN6Cj4+IEd1emlrOyBEYXZpZCBIb3dlbGxzCj4+IFN1YmplY3Q6IFJl OiBbUEFUQ0ggMS8ydjZdIHByb2Nmczogc2hvdyBoaWVyYXJjaHkgb2YgcGlkIG5hbWVzcGFjZQo+ Pgo+PiBBbSAwNS4xMS4yMDE0IHVtIDEzOjQxIHNjaHJpZWIgU2VyZ2UgRS4gSGFsbHluOgo+Pj4g UXVvdGluZyBSaWNoYXJkIFdlaW5iZXJnZXIgKHJpY2hhcmRAbm9kLmF0KToKPj4+PiBBbSAwNS4x MS4yMDE0IHVtIDExOjQxIHNjaHJpZWIgQ2hlbiBIYW54aWFvOgo+Pj4+PiBXZSBsYWNrIG9mIHBp ZCBoaWVyYXJjaHkgaW5mb3JtYXRpb24sIGFuZCB0aGlzIHdpbGwgbGVhZCB0bzoKPj4+Pj4gYSkg d2UgZG9uJ3Qga25vdyBwaWRzJyByZWxhdGlvbnNoaXAsIHdobyBpcyB3aG9zZSBjaGlsZDoKPj4+ Pj4gICAgL3Byb2MvUElEL25zL3BpZCBvbmx5IHRlbGwgdXMgd2hldGhlciB0d28gcGlkcyBsaXZl IGluIGRpZmZlcmVudCBucwo+Pj4+PiBiKSBicmluZyB0cm91YmxlIHRvIG5lc3RlZCBseGMgY29u dGFpbmVyIGNoZWNrL3Jlc3RvcmUvbWlncmF0aW9uCj4+Pj4+IGMpIGJyaW5nIHRyb3VibGUgdG8g cGlkIHRyYW5zbGF0aW9uIGJldHdlZW4gY29udGFpbmVyczsKPj4+Pj4KPj4+Pj4gVGhpcyBwYXRj aCB3aWxsIHNob3cgdGhlIGhpZXJhcmNoeSBvZiBwaWQgbmFtZXNwYWNlCj4+Pj4+IGJ5IHBpZG5z X2hpZXJhcmNoeSBsaWtlOgo+Pj4+Pgo+Pj4+PiBbcm9vdEBsb2NhbGhvc3Qgfl0jY2F0IC9wcm9j L3BpZG5zX2hpZXJhcmNoeQo+Pj4+PiAxODA2MCAxODEwMiAxNTM0Cj4+Pj4+IDE4MDYwIDE4MTAy IDE2MDAKPj4+Pj4gMTU1MAo+Pj4+Cj4+Pj4gSG1tLCB3aGF0IGFib3V0IHByaW50aW5nIHRoZSBw aWQgaGllcmFyY2h5IGluIHRoZSBzYW1lIHdheSBhcwo+PiAvcHJvYy9zZWxmL21vdW50aW5mbwo+ Pj4+IGRvZXMgd2l0aCBtb3VudCBuYW1lc3BhY2VzPwo+Pj4+IFlvdXIgY3VycmVudCBhcHByb2Fj aCBpcyBub3QgYmFkIGJ1dCB3ZSBzaG91bGQgcmVhbGx5IHRyeSB0byBiZSBjb25zaXN0ZW50Cj4+ IHdpdGggZXhpc3RpbmcKPj4+PiBzb3VyY2VzIG9mIGluZm9ybWF0aW9uLgo+Pj4KPj4+IEdvb2Qg cG9pbnQuICBIb3cgd291bGQgeW91IHN0cnVjdHVyZSBpdCB0byBtYWtlIGl0IGxvb2sgbW9yIGVs aWtlIG1vdW50aW5mbz8KPj4+IEFkZGluZyB0aGUgcGlkbnMgaW5vZGUgbnVtYmVyIChpbiBwbGFj ZSBvZiBhIG1vdW50IHNlcXVlbmNlIG51bWJlcikgbWlnaHQgYmUKPj4+IHVzZWZ1bCwgYnV0IGl0 IHNvdW5kcyBsaWtlIHlvdSBoYXZlIGEgbW9yZSBjb25jcmV0ZSBpZGVhPwo+Pgo+PiBKdXN0IGxp c3QgPGluaXRfUElEPiA8cGFyZW50X29mX2luaXRfUElEPi4gVGhpcyB3YXkgd2UgaGF2ZSBleGFj dGx5IG9uZQo+PiBpbmZvcm1hdGlvbiByZWNvcmQgcGVyIGxpbmUgYW5kIGFsd2F5cyBleGFjdGx5 IHR3byBjb2x1bW5zIHRvIHBhcnNlLgo+Pgo+PiBlLmcuCj4+IFtyb290QGxvY2FsaG9zdCB+XSNj YXQgL3Byb2MvcGlkbnNfaGllcmFyY2h5Cj4+IDE1NTAgMQo+PiAxODA2MCAxCj4+IDE4MTAyIDE4 MDYwCj4+IDE1MzQgMTgxMDIKPj4gMTYwMCAxODEwMgo+Pgo+IEJ1dCB0aGlzIHN0eWxlIGxhY2tz IG9mICpsZXZlbCogaW5mb3JtYXRpb246CgpJdCBkb2VzIG5vdC4KCj4gRXg6Cj4gMS0+MTgwNjAt PjE4MTAyLT4xNjAwLT4xNzAwCj4gSWYgd2Ugd2FudCB0byBjaGVjayB0aGUgMTcwMCdzIGxldmVs IGluIHBpZCBucwo+IFN0eWxlIDE6Cj4gMTgwNjAgMTgxMDIgMTYwMCAxNzAwCj4gCj4gU3R5bGUg MjoKPiAxODA2MCAxCj4gMTgxMDIgMTgwNjAKPiAxNjAwIDE4MTAyCj4gMTcwMCAxNjAwCj4gCj4g SWYgd2UgaGFkIGEgbGl0dGxlIG1vcmUgY29udGFpbmVycywKPiBTdHlsZSAyIHdvdWxkIG5vdCBi ZSBjbGVhciBlbm91Z2guCj4gMSBsaW5lIHZzICQoUElEIGxldmVsKSBsaW5lCgpBbnkgdHJpdmlh bCBwcm9ncmFtIGNhbiBmaW5kIG91dCB0aGUgbGV2ZWwgb2YgbmVzdGluZy4KCj4gSWYgdGhlcmUg d2VyZSBubyBtb3JlIHJlbGF0ZWQgaW5mb3JtYXRpb24gdG8gc2hvdywKPiBJIHRoaW5rIHN0eWxl IDEgbG9va3MgYmV0dGVyLgoKSXQgaXMgbm90IGFib3V0IGxvb2tpbmcgYmV0dGVyLCBpdCBpcyBh Ym91dCBwYXJzaW5nIGFuZCBiZWluZyBjb25zaXN0ZW50IHdpdGggZXhpc3RpbmcKaW50ZXJmYWNl cy4gL3Byb2MvcGlkbnNfaGllcmFyY2h5IHdpbGwgYmUgbW9zdGx5IHJlYWQgYnkgKnByb2dyYW1z Kiwgbm90IGh1bWFucy4KL3Byb2MvIGhhcyBhbHJlYWR5IHRvbyBtYW55IGhvcnJpYmxlIHRvIHBh cnNlIGZpbGVzLCBwbGVhc2UgZG9uJ3QgYWRkIGFub3RoZXIgb25lLgpUaGlzIGlzIGFsc28gd2h5 IHN5c2ZzIGhhcyB0aGUgb25lLXZhbHVlLXBlci1maWxlIHJ1bGUuCgpJZiBpdCBtYWtlcyB5b3Ug ZmVlbCBiZXR0ZXIgeW91IGNhbiBhZGQgYSB0aGlyZCBjb2x1bW4gdG8gdGhlIG91dHB1dCB3aGlj aCBpbmRpY2F0ZXMKdGhlIG5lc3RpbmcgbGV2ZWwgKG9yIHRoZSBkaXN0YW5jZSB0byB0aGUgaW5p dGlhbCBwaWRucykgLiBpLmUuClN0eWxlIDI6CjE4MDYwIDEgMQoxODEwMiAxODA2MCAyCjE2MDAg MTgxMDIgMwoxNzAwIDE2MDAgNAoKVGhhbmtzLAovL3JpY2hhcmQKX19fX19fX19fX19fX19fX19f X19fX19fX19fX19fX19fX19fX19fX19fX19fX18KQ29udGFpbmVycyBtYWlsaW5nIGxpc3QKQ29u dGFpbmVyc0BsaXN0cy5saW51eC1mb3VuZGF0aW9uLm9yZwpodHRwczovL2xpc3RzLmxpbnV4Zm91 bmRhdGlvbi5vcmcvbWFpbG1hbi9saXN0aW5mby9jb250YWluZXJz From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751652AbaKFIOG (ORCPT ); Thu, 6 Nov 2014 03:14:06 -0500 Received: from a.ns.miles-group.at ([95.130.255.143]:65275 "EHLO radon.swed.at" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751096AbaKFIOB (ORCPT ); Thu, 6 Nov 2014 03:14:01 -0500 Message-ID: <545B2DC4.1090005@nod.at> Date: Thu, 06 Nov 2014 09:13:56 +0100 From: Richard Weinberger User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.1.0 MIME-Version: 1.0 To: "Chen, Hanxiao" , "Serge E. Hallyn" CC: "Eric W. Biederman" , Serge Hallyn , Oleg Nesterov , "containers@lists.linux-foundation.org" , "linux-kernel@vger.kernel.org" , Mateusz Guzik , David Howells Subject: Re: [PATCH 1/2v6] procfs: show hierarchy of pid namespace References: <1415184115-12022-1-git-send-email-chenhanxiao@cn.fujitsu.com> <1415184115-12022-2-git-send-email-chenhanxiao@cn.fujitsu.com> <545A13DA.3090207@nod.at> <20141105124111.GA19563@mail.hallyn.com> <545A1D53.3070507@nod.at> <5871495633F38949900D2BF2DC04883E61F2B2@G08CNEXMBPEKD02.g08.fujitsu.local> In-Reply-To: <5871495633F38949900D2BF2DC04883E61F2B2@G08CNEXMBPEKD02.g08.fujitsu.local> Content-Type: text/plain; charset=gbk Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Am 06.11.2014 um 06:48 schrieb Chen, Hanxiao: > > >> -----Original Message----- >> From: Richard Weinberger [mailto:richard@nod.at] >> Sent: Wednesday, November 05, 2014 8:52 PM >> To: Serge E. Hallyn >> Cc: Chen, Hanxiao/³Â êÏÏö; Eric W. Biederman; Serge Hallyn; Oleg Nesterov; >> containers@lists.linux-foundation.org; linux-kernel@vger.kernel.org; Mateusz >> Guzik; David Howells >> Subject: Re: [PATCH 1/2v6] procfs: show hierarchy of pid namespace >> >> Am 05.11.2014 um 13:41 schrieb Serge E. Hallyn: >>> Quoting Richard Weinberger (richard@nod.at): >>>> Am 05.11.2014 um 11:41 schrieb Chen Hanxiao: >>>>> We lack of pid hierarchy information, and this will lead to: >>>>> a) we don't know pids' relationship, who is whose child: >>>>> /proc/PID/ns/pid only tell us whether two pids live in different ns >>>>> b) bring trouble to nested lxc container check/restore/migration >>>>> c) bring trouble to pid translation between containers; >>>>> >>>>> This patch will show the hierarchy of pid namespace >>>>> by pidns_hierarchy like: >>>>> >>>>> [root@localhost ~]#cat /proc/pidns_hierarchy >>>>> 18060 18102 1534 >>>>> 18060 18102 1600 >>>>> 1550 >>>> >>>> Hmm, what about printing the pid hierarchy in the same way as >> /proc/self/mountinfo >>>> does with mount namespaces? >>>> Your current approach is not bad but we should really try to be consistent >> with existing >>>> sources of information. >>> >>> Good point. How would you structure it to make it look mor elike mountinfo? >>> Adding the pidns inode number (in place of a mount sequence number) might be >>> useful, but it sounds like you have a more concrete idea? >> >> Just list . This way we have exactly one >> information record per line and always exactly two columns to parse. >> >> e.g. >> [root@localhost ~]#cat /proc/pidns_hierarchy >> 1550 1 >> 18060 1 >> 18102 18060 >> 1534 18102 >> 1600 18102 >> > But this style lacks of *level* information: It does not. > Ex: > 1->18060->18102->1600->1700 > If we want to check the 1700's level in pid ns > Style 1: > 18060 18102 1600 1700 > > Style 2: > 18060 1 > 18102 18060 > 1600 18102 > 1700 1600 > > If we had a little more containers, > Style 2 would not be clear enough. > 1 line vs $(PID level) line Any trivial program can find out the level of nesting. > If there were no more related information to show, > I think style 1 looks better. It is not about looking better, it is about parsing and being consistent with existing interfaces. /proc/pidns_hierarchy will be mostly read by *programs*, not humans. /proc/ has already too many horrible to parse files, please don't add another one. This is also why sysfs has the one-value-per-file rule. If it makes you feel better you can add a third column to the output which indicates the nesting level (or the distance to the initial pidns) . i.e. Style 2: 18060 1 1 18102 18060 2 1600 18102 3 1700 1600 4 Thanks, //richard