From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Serge E. Hallyn" Subject: Re: [RFC v17][PATCH 22/60] c/r: external checkpoint of a task other than ourself Date: Thu, 23 Jul 2009 09:54:38 -0500 Message-ID: <20090723145438.GA12945@us.ibm.com> References: <1248256822-23416-1-git-send-email-orenl@librato.com> <1248256822-23416-23-git-send-email-orenl@librato.com> <20090722175223.GA19389@us.ibm.com> <4A67E7D7.9060800@librato.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <4A67E7D7.9060800-RdfvBDnrOixBDgjK7y7TUQ@public.gmane.org> Sender: linux-api-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Oren Laadan Cc: Andrew Morton , Linus Torvalds , containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-mm-Bw31MaZKKs3YtjvyW6yDsg@public.gmane.org, linux-api-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Dave Hansen , Ingo Molnar , "H. Peter Anvin" , Alexander Viro , Pavel Emelyanov , Alexey Dobriyan , Oren Laadan List-Id: linux-api@vger.kernel.org Quoting Oren Laadan (orenl-RdfvBDnrOixBDgjK7y7TUQ@public.gmane.org): > > > Serge E. Hallyn wrote: > > Quoting Oren Laadan (orenl-RdfvBDnrOixBDgjK7y7TUQ@public.gmane.org): > >> Now we can do "external" checkpoint, i.e. act on another task. > > > > ... > > > >> long do_checkpoint(struct ckpt_ctx *ctx, pid_t pid) > >> { > >> long ret; > >> > >> + ret = init_checkpoint_ctx(ctx, pid); > >> + if (ret < 0) > >> + return ret; > >> + > >> + if (ctx->root_freezer) { > >> + ret = cgroup_freezer_begin_checkpoint(ctx->root_freezer); > >> + if (ret < 0) > >> + return ret; > >> + } > > > > Self-checkpoint of a task in root freezer is now denied, though. > > > > Was that intentional? > > Yes. > > "root freezer" is an arbitrary task in the checkpoint subtree or > container. It is used to verify that all checkpointed tasks - except > for current, if doing self-checkpoint - belong to the same freezer > group. > > Since current is busy calling checkpoint(2), and since we only permit > checkpoint of (cgroup-) frozen tasks, then - by definition - it cannot > possibly belong to the same group. If it did, it would itself be frozen > like its fellows and unable to call checkpoint(2). > > Oren. Ok, well I don't know what was happening yesterday. Today it's restart that is failing, and as you pointed out on irc that's on s390 only. I'll send out a patch this afternoon to fix that. Yesterday I must not have read the output right I guess... thanks, -serge -- To unsubscribe from this list: send the line "unsubscribe linux-api" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html