From mboxrd@z Thu Jan 1 00:00:00 1970 From: Balbir Singh Subject: Re: memrlimit controller merge to mainline Date: Fri, 25 Jul 2008 15:08:42 -0400 Message-ID: <488A24BA.4060204@linux.vnet.ibm.com> References: <6599ad830807250114h7ab0fdb1u98c0968961647642@mail.gmail.com> <4889D5EE.4010601@linux.vnet.ibm.com> Reply-To: balbir-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: 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: Hugh Dickins Cc: Linux Containers , Paul Menage , Andrew Morton List-Id: containers.vger.kernel.org Hugh Dickins wrote: > On Fri, 25 Jul 2008, Balbir Singh wrote: >> I'll try and recreate the problem and fix it. If memrlimit_cgroup_uncharge_as() >> created the problem, it's most likely related to mm->owner not being correct and >> we are dereferencing the wrong memory. >> >> Thanks for the bug report, I'll look further. > > Good luck! I have only seen it once, on a dual-core laptop; though > I don't remember to try swapoff while busy as often as I should (be > sure to alternate between a couple or more of swapareas, so you can > swap a new one on just before swapping an old one off, to be pretty > sure of success). > Thanks, that's very useful information. I would have never tried juggling swap devices otherwise. > May be easier to find in the source: my suspicion is that a bad > mm_users assumption will come into it. But I realize now that it > could be entirely unrelated to memrlimit, just that uncharge_as > was the one to get hit by bad refcounting elsewhere. > > Oh, that reminds me, I never reported back on my res_counter warnings > at shutdown: never saw them again, once I added in the set of changes > you came up with shortly after that - thanks. > I am glad those messages are gone, thanks for the bug report. I find bug fixing more exciting that kernel development on most occasions. -- Warm Regards, Balbir Singh Linux Technology Center IBM, ISTL