From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sukadev Bhattiprolu Subject: [C/R] threaded application Date: Sat, 16 May 2009 19:31:25 -0700 Message-ID: <20090517023125.GA30716@us.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline 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: Oren Laadan Cc: Containers List-Id: containers.vger.kernel.org Probably premature :-) but tried to C/R a simple threaded application (running as container-init). First got an -EINVAL due to following check in may_checkpoint_task(): /* * FIX: for now, disallow siblings of container init created * via CLONE_PARENT (unclear if they will remain possible) */ if (ctx->root_init && t != ctx->root_task && t->real_parent == ctx->root_task->real_parent) Assuming we are unintentionally excluding CLONE_THREAD with the above check, I added a check for tgid: if (ctx->root_init && t != ctx->root_task && t->real_parent == ctx->root_task->real_parent && t->tgid != ctx->root_task->tgid) { This got past the -EINVAL but the test failed the ckpt_obj_contained() check. c/r: FILE users 2 != count 6 objref 9 The main-thread opened a single file (log file). The other threads don't write to it (yet). The count '6' corresponds to the number of threads in the application. I suspect that C/R code is incrementing obj->users once per thread for the log file even though the threads share the file_struct reference. (pthread_create() sets CLONE_FILES so the file_struct is shared between threads). Will post my test programs to Serge's new git-tree next week. Sukadev