Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934615Ab0KQIRA (ORCPT ); Wed, 17 Nov 2010 03:17:00 -0500 Received: from smtp-out.google.com ([216.239.44.51]:2127 "EHLO smtp-out.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S934523Ab0KQIQ5 (ORCPT ); Wed, 17 Nov 2010 03:16:57 -0500 DomainKey-Signature: a=rsa-sha1; c=nofws; d=google.com; s=beta; h=date:from:x-x-sender:to:cc:subject:in-reply-to:message-id :references:user-agent:mime-version:content-type; b=wroUXHmnUtOw29xCQADYHhWZhX8AaOYhhZ9GuDiFCgapvmLOJiNqpbxFJKuuyj3wL2 UAjvVhXohVmySsA3rveQ== Date: Wed, 17 Nov 2010 00:16:52 -0800 (PST) From: David Rientjes X-X-Sender: rientjes@chino.kir.corp.google.com To: Shaohui Zheng cc: akpm@linux-foundation.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, haicheng.li@linux.intel.com, lethal@linux-sh.org, ak@linux.intel.com, shaohui.zheng@linux.intel.com, Dave Hansen , Christoph Lameter , Haicheng Li Subject: Re: [3/8,v3] NUMA Hotplug Emulator: Userland interface to hotplug-add fake offlined nodes. In-Reply-To: <20101117021000.638336620@intel.com> Message-ID: References: <20101117020759.016741414@intel.com> <20101117021000.638336620@intel.com> User-Agent: Alpine 2.00 (DEB 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2019 Lines: 53 On Wed, 17 Nov 2010, shaohui.zheng@intel.com wrote: > From: Haicheng Li > > Add a sysfs entry "probe" under /sys/devices/system/node/: > > - to show all fake offlined nodes: > $ cat /sys/devices/system/node/probe > > - to hotadd a fake offlined node, e.g. nodeid is N: > $ echo N > /sys/devices/system/node/probe > This would be much more powerful if we just reserved an amount of memory at boot and then allowed users to hot-add a given amount with an non-online node id. Then we can test nodes of various sizes rather than being statically committed at boot. This should be fairly straight-forward by faking ACPI_SRAT_MEM_HOT_PLUGGABLE entries, for example. > Index: linux-hpe4/mm/Kconfig > =================================================================== > --- linux-hpe4.orig/mm/Kconfig 2010-11-15 17:13:02.443461606 +0800 > +++ linux-hpe4/mm/Kconfig 2010-11-15 17:21:05.535335091 +0800 > @@ -147,6 +147,21 @@ > depends on MEMORY_HOTPLUG && ARCH_ENABLE_MEMORY_HOTREMOVE > depends on MIGRATION > > +config NUMA_HOTPLUG_EMU > + bool "NUMA hotplug emulator" > + depends on X86_64 && NUMA && MEMORY_HOTPLUG > + > + ---help--- > + > +config NODE_HOTPLUG_EMU > + bool "Node hotplug emulation" > + depends on NUMA_HOTPLUG_EMU && MEMORY_HOTPLUG > + ---help--- > + Enable Node hotplug emulation. The machine will be setup with > + hidden virtual nodes when booted with "numa=hide=N*size", where > + N is the number of hidden nodes, size is the memory size per > + hidden node. This is only useful for debugging. > + That's clearly wrong, but I don't see why this needs to be a new Kconfig option to begin with, can't we enable all of this functionality by default under CONFIG_NUMA_EMU && CONFIG_MEMORY_HOTPLUG? -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/