LKML Archive on lore.kernel.org help / color / mirror / Atom feed
From: "Serge E. Hallyn" <serue@us.ibm.com> To: Nick Andrew <nick@nick-andrew.net> Cc: "Serge E. Hallyn" <serue@us.ibm.com>, trivial@kernel.org, linux-kernel@vger.kernel.org, Pavel Emelyanov <xemul@openvz.org>, Randy Dunlap <randy.dunlap@oracle.com>, Paul Menage <menage@google.com>, Paul Jackson <pj@sgi.com>, Valdis Kletnieks <Valdis.Kletnieks@vt.edu> Subject: Re: [PATCH 2.6.25-rc2 3/9] Kconfig: Improve init/Kconfig help descriptions - NAMESPACES Date: Fri, 22 Feb 2008 21:45:39 -0600 [thread overview] Message-ID: <20080223034539.GA22100@sergelap.austin.ibm.com> (raw) In-Reply-To: <20080223011258.GH2169@tull.net> Quoting Nick Andrew (nick@nick-andrew.net): > On Fri, Feb 22, 2008 at 04:14:12PM -0600, Serge E. Hallyn wrote: > > Quoting Nick Andrew (nick@nick-andrew.net): > > > config UTS_NS > > > bool "UTS namespace" > > > depends on NAMESPACES > > > help > > > - In this namespace tasks see different info provided with the > > > - uname() system call > > > + Enable support for multiple UTS system attributes. > > > + > > > + Each UTS namespace provides an individual view of the > > > + information returned by the uname() system call including > > > + hostname, kernel version and domain name. > > > + > > > + This is used by container systems (e.g. vservers) so that > > > + each container has its own hostname and other attributes. > > > + Tasks in the container are placed in the UTS namespace > > > + corresponding to the container. > > > > this paragraph reads a little weird... really what happens is that > > each forked task is in the same UTS namespace as its parent, unless > > it was cloned with CLONE_NEWUTS or has done unshare(CLONE_NEWUTS), > > in which case it receives a copy. > > You mean only the third paragraph, right? I hope the other two are > accurate. > > I'm trying to describe how the feature is used by container systems > and my description is obviously inaccurate. There are subtle semantic > differences between the way the different namespaces work, which you've > pointed out. I think mentioning CLONE_NEWUTS or other flags is too > technical for help descriptions. > > For UTS_NS and IPC_NS I think I could remove that paragraph because > the end user hint "Answer Y if you will be using a container system" > remains. For USER_NS and PID_NS however, these features are tagged > EXPERIMENTAL so the hint is "If unsure, say N" and I think I need > to at least mention the use in container systems or find some better > clarifying description which doesn't get too technical. > > > > + This is used by container systems (e.g. vservers). > > > + Tasks in the container are placed in the IPC namespace > > > + corresponding to the container. > > > > Same as with UTS, except that upon CLONE_NEWIPC the task receives a > > blank new ipc namespace, not a copy of the original. > > Per above my response is to remove the paragraph. > > > > config PID_NS > > > [...] > > > default n > > > depends on NAMESPACES && EXPERIMENTAL > > > help > > > - Suport process id namespaces. This allows having multiple > > > - process with the same pid as long as they are in different > > > - pid namespaces. This is a building block of containers. > > > + Enable experimental support for hierarchical process id namespaces. > > > > > > - Unless you want to work with an experimental feature > > > - say N here. > > > + This is a function used by container-based virtualisation > > > + systems (e.g. vservers). Each process will have a distinct > > > + Process ID in each PID namespace which the process is in. > > > + Processes in the container are placed in the PID namespace > > > + corresponding to the container, and cannot see or affect > > > + processes in any parent PID namespace. > > > > A cloned process inherits the pid namespace hierarchy from its > > parent. If it was cloned with CLONE_NEWPID, the hierarchy is > > topped with one additional newly created pid namespace. This > > is the only pid namespace in which the new process will be able > > to see processes, while it will be visible in all namespaces in > > its pidns hierarchy. > > Yes, I understand that. Would you agree that your problem is with the > wording "Processes in the container are placed in the PID namespace > corresponding to the container"? And that this is the part that needs > to be fixed? Yup. thanks, -serge > ... todo = revisit these descriptions soon, not today though > > Nick. > -- > PGP Key ID = 0x418487E7 http://www.nick-andrew.net/ > PGP Key fingerprint = B3ED 6894 8E49 1770 C24A 67E3 6266 6EB9 4184 87E7
prev parent reply other threads:[~2008-02-23 3:46 UTC|newest] Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top 2008-02-19 14:06 Improve init/Kconfig help descriptions [PATCH 0/9] Nick Andrew 2008-02-19 14:09 ` Improve init/Kconfig help descriptions [PATCH 1/9] Nick Andrew 2008-02-19 14:11 ` Improve init/Kconfig help descriptions [PATCH 2/9] Nick Andrew 2008-02-19 14:33 ` Improve init/Kconfig help descriptions [PATCH 3/9] Nick Andrew 2008-02-19 14:42 ` Pavel Emelyanov 2008-02-19 15:10 ` Nick Andrew 2008-02-19 15:16 ` Pavel Emelyanov 2008-02-19 15:50 ` Serge E. Hallyn 2008-02-19 16:44 ` Randy Dunlap 2008-02-19 22:41 ` Nick Andrew 2008-02-20 12:19 ` [PATCH 2.6.25-rc2 3/9] config: Improve init/Kconfig help descriptions - namespaces Nick Andrew 2008-02-20 12:23 ` Pavel Emelyanov 2008-02-20 13:01 ` Nick Andrew 2008-02-20 13:07 ` Pavel Emelyanov 2008-02-20 16:50 ` serge 2008-02-20 23:10 ` Nick Andrew 2008-02-19 14:38 ` Improve init/Kconfig help descriptions [PATCH 4/9] Nick Andrew 2008-02-20 3:42 ` Valdis.Kletnieks 2008-02-20 22:17 ` Nick Andrew 2008-02-19 14:53 ` Improve init/Kconfig help descriptions [PATCH 5/9] Nick Andrew 2008-02-19 20:17 ` Randy Dunlap 2008-02-19 15:12 ` Improve init/Kconfig help descriptions [PATCH 6/9] Nick Andrew 2008-02-19 15:39 ` Paul Jackson 2008-02-20 12:41 ` Nick Andrew 2008-02-20 16:43 ` Paul Jackson 2008-02-20 2:04 ` Paul Menage 2008-02-20 2:54 ` Nick Andrew 2008-02-20 3:12 ` Paul Menage 2008-02-20 16:55 ` serge 2008-02-20 21:31 ` Nick Andrew 2008-02-19 15:15 ` Improve init/Kconfig help descriptions [PATCH 7/9] Nick Andrew 2008-02-19 15:21 ` Improve init/Kconfig help descriptions [PATCH 8/9] Nick Andrew 2008-02-19 15:27 ` Improve init/Kconfig help descriptions [PATCH 9/9] Nick Andrew 2008-02-20 22:33 ` [PATCH 2.6.25-rc2 1/9] init: Improve init/Kconfig help descriptions part 1 Nick Andrew [not found] ` <200802220014.m1M0Dh5r022354@rgminet03.oracle.com> 2008-02-22 0:19 ` [PATCH 2.6.25-rc2 5/9] Kconfig: Improve init/Kconfig help descriptions - IKCONFIG etc Randy Dunlap 2008-02-22 0:48 ` [PATCH 2.6.25-rc2 1/9] Kconfig: Improve init/Kconfig help descriptions part 1 Nick Andrew 2008-02-22 0:49 ` [PATCH 2.6.25-rc2 2/9] Kconfig: Improve init/Kconfig help descriptions - TASKSTATS Nick Andrew 2008-02-22 0:51 ` [PATCH 2.6.25-rc2 3/9] Kconfig: Improve init/Kconfig help descriptions - NAMESPACES Nick Andrew 2008-02-27 23:00 ` Nick Andrew 2008-02-27 23:08 ` Serge E. Hallyn 2008-02-22 0:52 ` [PATCH 2.6.25-rc2 4/9] Kconfig: Improve init/Kconfig help descriptions - AUDIT Nick Andrew 2008-02-22 0:54 ` [PATCH 2.6.25-rc2 5/9] Kconfig: Improve init/Kconfig help descriptions - IKCONFIG etc Nick Andrew 2008-02-22 0:55 ` [PATCH 2.6.25-rc2 6/9] Kconfig: Improve init/Kconfig help descriptions - CGROUPS Nick Andrew 2008-02-22 0:56 ` [PATCH 2.6.25-rc2 7/9] Kconfig: Improve init/Kconfig help descriptions - EMBEDDED etc Nick Andrew 2008-02-22 0:58 ` [PATCH 2.6.25-rc2 8/9] Kconfig: Improve init/Kconfig help descriptions - SLAB Nick Andrew 2008-02-22 0:59 ` [PATCH 2.6.25-rc2 9/9] Kconfig: Improve init/Kconfig help descriptions - MODULES Nick Andrew [not found] ` <200802220010.m1M0Arr7024044@vzorg.swsoft.net> 2008-02-22 8:14 ` [PATCH 2.6.25-rc2 3/9] Kconfig: Improve init/Kconfig help descriptions - NAMESPACES Pavel Emelyanov [not found] ` <200802220010.m1M0Auqn024414@e5.ny.us.ibm.com> 2008-02-22 22:14 ` Serge E. Hallyn 2008-02-23 1:12 ` Nick Andrew 2008-02-23 3:45 ` Serge E. Hallyn [this message]
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=20080223034539.GA22100@sergelap.austin.ibm.com \ --to=serue@us.ibm.com \ --cc=Valdis.Kletnieks@vt.edu \ --cc=linux-kernel@vger.kernel.org \ --cc=menage@google.com \ --cc=nick@nick-andrew.net \ --cc=pj@sgi.com \ --cc=randy.dunlap@oracle.com \ --cc=trivial@kernel.org \ --cc=xemul@openvz.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is a public inbox, see mirroring instructions for how to clone and mirror all data and code used for this inbox; as well as URLs for NNTP newsgroup(s).