From mboxrd@z Thu Jan 1 00:00:00 1970 From: Oren Laadan Subject: Re: [RFC v14-rc2][PATCH 16/29] A new file type (CR_FD_OBJREF) for a file descriptor already setup Date: Wed, 01 Apr 2009 10:13:54 -0400 Message-ID: <49D376A2.9050203@cs.columbia.edu> References: <1238477349-11029-1-git-send-email-orenl@cs.columbia.edu> <1238477349-11029-17-git-send-email-orenl@cs.columbia.edu> <20090401135952.GA16973@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20090401135952.GA16973-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: "Serge E. Hallyn" Cc: containers-cunTk1MwBs9QetFLy7KEm3xJsTq8ys+cHZ5vskTnxNA@public.gmane.org, Dave Hansen List-Id: containers.vger.kernel.org Serge E. Hallyn wrote: > Quoting Oren Laadan (orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org): >> While file pointers are shared objects, they may share an underlying >> object themselves. For instance, file pointers of both ends of a pipe >> that share the same pipe inode. In this case, the shared entity to >> handle is the inode that is shared among two file pointers (e.g read- >> and write- ends). In this sort of "nested sharing" we need only save >> the underlying object once (upon first encounter) on checkpoint, and >> restore it only once during restart. >> >> To checkpoint a file descriptor of this sort, we first lookup the >> inode in the hash table: > > Sorry I've not followed well on irc. What is the plan and timeline > with respect to this and Dave's fops approach? Is someone rewriting > the pipes patches on top of that? Will that replace this patch as > well? Who is doing it, and when will we see that patch? > The fops approach is already implemented for checkpoint. I already modified the pipe implementation accordingly. So there are 'generic_file_checkpoint()' and 'pipe_file_checkpoint()' both in place. The restart is remains the same for all file types. I think Dave is working on another change that will modify the format of the checkpoint. > I'm just wondering how closely to review the next 3 patches. Please do :) Oren.