From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tang Chen Subject: Re: [PATCH part5 0/7] Arrange hotpluggable memory as ZONE_MOVABLE. Date: Tue, 13 Aug 2013 14:14:25 +0800 Message-ID: <5209CEC1.8070908@cn.fujitsu.com> References: <1375956979-31877-1-git-send-email-tangchen@cn.fujitsu.com> <20130812145016.GI15892@htj.dyndns.org> <5208FBBC.2080304@zytor.com> <20130812152343.GK15892@htj.dyndns.org> <52090D7F.6060600@gmail.com> <20130812164650.GN15892@htj.dyndns.org> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20130812164650.GN15892@htj.dyndns.org> Sender: owner-linux-mm@kvack.org To: Tejun Heo Cc: Tang Chen , "H. Peter Anvin" , robert.moore@intel.com, lv.zheng@intel.com, rjw@sisk.pl, lenb@kernel.org, tglx@linutronix.de, mingo@elte.hu, akpm@linux-foundation.org, trenn@suse.de, yinghai@kernel.org, jiang.liu@huawei.com, wency@cn.fujitsu.com, laijs@cn.fujitsu.com, isimatu.yasuaki@jp.fujitsu.com, izumi.taku@jp.fujitsu.com, mgorman@suse.de, minchan@kernel.org, mina86@mina86.com, gong.chen@linux.intel.com, vasilis.liaskovitis@profitbricks.com, lwoodman@redhat.com, riel@redhat.com, jweiner@redhat.com, prarit@redhat.com, zhangyanfei@cn.fujitsu.com, yanghy@cn.fujitsu.com, x86@kernel.org, linux-doc@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-acpi@vger.kernel.org, "Luck, Tony (tony.luck@intel.com)" List-Id: linux-acpi@vger.kernel.org On 08/13/2013 12:46 AM, Tejun Heo wrote: ...... > > * Adding an option to tell the kernel to try to stay away from > hotpluggable nodes is fine. I have no problem with that at all. > > * The patchsets upto this point have been somehow trying to reorder > operations shomehow such that *no* memory allocation happens before > memblock is populated with hotplug information. > > * However, we already *know* that the memory the kernel image is > occupying won't be removeable. It's highly likely that the amount > of memory allocation before NUMA / hotplug information is fully > populated is pretty small. Also, it's highly likely that small > amount of memory right after the kernel image is contained in the > same NUMA node, so if we allocate memory close to the kernel image, > it's likely that we don't contaminate hotpluggable node. We're > talking about few megs at most right after the kernel image. I > can't see how that would make any noticeable difference. > > * Once hotplug information is available, allocation can happen as > usual and the kernel can report the nodes which are actually > hotpluggable - marked as hotpluggable by the firmware&& didn't get > contaminated during early alloc&& didn't get overflow allocations > afterwards. Note that we need such mechanism no matter what as the > kernel image can be loaded into hotpluggable nodes and reporting > that to userland is the only thing the kernel can do for cases like > that short of denying memory unplug on such nodes. > Hi tj, hpa, luck, yinghai, So if all of you agree on the idea above from tj, I think we can do it in this way. Will update the patches to allocate memory near kernel image before SRAT is parsed. Thanks. -- 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