From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dan Smith Subject: Re: [PATCH] Clear the objhash before completing restart, but delay free (v2) Date: Mon, 01 Nov 2010 10:01:43 -0700 Message-ID: <87oca9vuyw.fsf@localhost6.localdomain6> References: <1287496991-18207-1-git-send-email-danms@us.ibm.com> <4CCEE9AD.7010105@cs.columbia.edu> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <4CCEE9AD.7010105-eQaUEPhvms7ENvBUuze7eA@public.gmane.org> (Oren Laadan's message of "Mon\, 01 Nov 2010 12\:24\:13 -0400") 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-qjLDD68F18O7TbgM5vRIOg@public.gmane.org, matthltc-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org List-Id: containers.vger.kernel.org OL> Does this patch solve the performance problem in freeing all OL> the objhash entries upfront (e.g. before letting userspace OL> resume) ? OL> If so, is there still a performance hit for doing the 'clear' OL> portion early before resuming the tasks ? How much does it OL> depend on the complexity of the hierarchy being checkpointed ? I've actually been unable to detect any real different in performance between this and the way it was before. I've run it against several different large checkpoints (multiple processes, with sockets, IPC, many files open, etc). I have another option for the functionality, which is to mark only specific items as needing to be free()'d early, but I can't discern a difference between that or this option either. What I can discern is that this patch is more likely to prevent similar issues in the future by making the behavior of the hash far more generally correct, IMHO. -- Dan Smith IBM Linux Technology Center email: danms-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org