From mboxrd@z Thu Jan 1 00:00:00 1970 Subject: Re: [PATCH take2] Memoryless nodes: use "node_memory_map" for cpuset mems_allowed validation From: Lee Schermerhorn In-Reply-To: <20070724161925.GB18510@us.ibm.com> References: <20070711182219.234782227@sgi.com> <20070711182250.005856256@sgi.com> <1185286525.5649.27.camel@localhost> <20070724161925.GB18510@us.ibm.com> Content-Type: text/plain Date: Tue, 24 Jul 2007 15:01:33 -0400 Message-Id: <1185303693.5649.45.camel@localhost> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org Return-Path: To: Nishanth Aravamudan Cc: Christoph Lameter , Paul Jackson , akpm@linux-foundation.org, kxr@sgi.com, linux-mm@kvack.org, KAMEZAWA Hiroyuki List-ID: On Tue, 2007-07-24 at 09:19 -0700, Nishanth Aravamudan wrote: > On 24.07.2007 [10:15:25 -0400], Lee Schermerhorn wrote: > > Memoryless Nodes: use "node_memory_map" for cpusets - take 2 > > > > Against 2.6.22-rc6-mm1 atop Christoph Lameter's memoryless nodes > > series > > > > take 2: > > + replaced node_online_map in cpuset_current_mems_allowed() > > with node_states[N_MEMORY] > > + replaced node_online_map in cpuset_init_smp() with > > node_states[N_MEMORY] > > > > cpusets try to ensure that any node added to a cpuset's > > mems_allowed is on-line and contains memory. The assumption > > was that online nodes contained memory. Thus, it is possible > > to add memoryless nodes to a cpuset and then add tasks to this > > cpuset. This results in continuous series of oom-kill and > > apparent system hang. > > > > Change cpusets to use node_states[N_MEMORY] [a.k.a. > > node_memory_map] in place of node_online_map when vetting > > memories. Return error if admin attempts to write a non-empty > > mems_allowed node mask containing only memoryless-nodes. > > I think you still are missing a few comment changes (anything mentioning > 'track'ing node_online_map will need to be changed, I think). Also, I > don't see the necessary change in common_cpu_mem_hotplug_unplug() > similar to cpuset_init_smp()'s change. Sorry. Multitasking meltdown... Will fix. Meanwhile: I've tested your 3 patches atop Christoph's series [on 22-rc6-mm1], with and without my cpuset patch and I can't reproduce the hang I saw a couple of days ago :-(. I hate it when that happens! Perhaps some system daemon started up during the test that hung. Later, Lee -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: email@kvack.org