From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oren Laadan Subject: Re: [RFC][PATCH 7/7][v2] Define clone_with_pids syscall Date: Fri, 29 May 2009 16:01:50 -0400 Message-ID: <4A203F2E.1060807@cs.columbia.edu> References: <20090528043748.GA16522@us.ibm.com> <20090528043945.GG16522@us.ibm.com> <4A1EA73F.1080802@cs.columbia.edu> <20090528173019.GB26183@us.ibm.com> <4A1F228C.2020201@cs.columbia.edu> <20090529030558.GA2548@us.ibm.com> <4A1F72A1.4070103@cs.columbia.edu> <20090529054645.GA3344@us.ibm.com> <4A1F78AF.6030404@cs.columbia.edu> <20090529170616.GA12597@us.ibm.com> <20090529193416.GB12597@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090529193416.GB12597-r/Jw6+rmf7HQT0dZR+AlfA@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: Sukadev Bhattiprolu Cc: Containers , "David C. Hansen" List-Id: containers.vger.kernel.org Sukadev Bhattiprolu wrote: > Sukadev Bhattiprolu [sukadev-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org] wrote: > | Oren Laadan [orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org] wrote: > > I am not sure what the semantics should be for this case: > > - checkpoint a process that is in level-3 pid namespace > - restart in a level-2 or level-1 pid namespace > Meaning: a container root was at level-3, so tasks in the container were level-3 through level-(3+N), where N is the in-container depth so to speak. Then it was restarted such that the base became level-2 or level-1. I think we already covered this. > clone_with_pids() will fail now since number of pids specified would > be 4 but kernel expects only 2 or 3. mktree/restart program cannot > figure out current nesting to trim the target-pids. > > Should we remove the check of user-pids exceeding the current nesting > level and simply ignore the pids from the older namespaces ? It seems to me that the current behavior is correct: I can't think of a case where trimming (silently) would make sense, or where a program would end up giving more pids that it's nesting level. Oren.