From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx193.postini.com [74.125.245.193]) by kanga.kvack.org (Postfix) with SMTP id EB4376B003C for ; Mon, 8 Apr 2013 13:22:47 -0400 (EDT) From: Toshi Kani Subject: [PATCH v2 0/3] Support memory hot-delete to boot memory Date: Mon, 8 Apr 2013 11:09:53 -0600 Message-Id: <1365440996-30981-1-git-send-email-toshi.kani@hp.com> Sender: owner-linux-mm@kvack.org List-ID: To: akpm@linux-foundation.org Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxram@us.ibm.com, guz.fnst@cn.fujitsu.com, tmac@hp.com, isimatu.yasuaki@jp.fujitsu.com, wency@cn.fujitsu.com, tangchen@cn.fujitsu.com, jiang.liu@huawei.com, Toshi Kani Memory hot-delete to a memory range present at boot causes an error message in __release_region(), such as: Trying to free nonexistent resource <0000000070000000-0000000077ffffff> Hot-delete operation still continues since __release_region() is a void function, but the target memory range is not freed from iomem_resource as the result. This also leads a failure in a subsequent hot-add operation to the same memory range since the address range is still in-use in iomem_resource. This problem happens because the granularity of memory resource ranges may be different between boot and hot-delete. During bootup, iomem_resource is set up from the boot descriptor table, such as EFI Memory Table and e820. Each resource entry usually covers the whole contiguous memory range. Hot-delete request, on the other hand, may target to a particular range of memory resource, and its size can be much smaller than the whole contiguous memory. Since the existing release interfaces like __release_region() require a requested region to be exactly matched to a resource entry, they do not allow a partial resource to be released. This patchset introduces release_mem_region_adjustable() for memory hot-delete operations, which allows releasing a partial memory range and adjusts remaining resource accordingly. This patchset makes no changes to the existing interfaces since their restriction is still valid for I/O resources. --- v2: Updated release_mem_region_adjustable() per code reviews from Yasuaki Ishimatsu, Ram Pai and Gu Zheng. --- Toshi Kani (3): resource: Add __adjust_resource() for internal use resource: Add release_mem_region_adjustable() mm: Change __remove_pages() to call release_mem_region_adjustable() --- include/linux/ioport.h | 2 + kernel/resource.c | 128 ++++++++++++++++++++++++++++++++++++++++++++----- mm/memory_hotplug.c | 11 ++++- 3 files changed, 126 insertions(+), 15 deletions(-) -- 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