Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755746Ab2F3Pvd (ORCPT ); Sat, 30 Jun 2012 11:51:33 -0400 Received: from mail-pz0-f46.google.com ([209.85.210.46]:57843 "EHLO mail-pz0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751155Ab2F3Pvb (ORCPT ); Sat, 30 Jun 2012 11:51:31 -0400 Message-ID: <4FEF2075.2050603@gmail.com> Date: Sat, 30 Jun 2012 23:51:17 +0800 From: Jiang Liu User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:13.0) Gecko/20120615 Thunderbird/13.0.1 MIME-Version: 1.0 To: Yasuaki Ishimatsu CC: linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, len.brown@intel.com, benh@kernel.crashing.org, paulus@samba.org, cl@linux.com, minchan.kim@gmail.com, akpm@linux-foundation.org, kosaki.motohiro@jp.fujitsu.com, wency@cn.fujitsu.com Subject: Re: [RFC PATCH 2/12] memory-hogplug : check memory offline in offline_pages References: <4FEA9C88.1070800@jp.fujitsu.com> <4FEA9DB1.7010303@jp.fujitsu.com> In-Reply-To: <4FEA9DB1.7010303@jp.fujitsu.com> Content-Type: text/plain; charset=ISO-2022-JP Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3723 Lines: 95 On 06/27/2012 01:44 PM, Yasuaki Ishimatsu wrote: > When offline_pages() is called to offlined memory, the function fails since > all memory has been offlined. In this case, the function should succeed. > The patch adds the check function into offline_pages(). > > CC: Len Brown > CC: Benjamin Herrenschmidt > CC: Paul Mackerras > CC: Christoph Lameter > Cc: Minchan Kim > CC: Andrew Morton > CC: KOSAKI Motohiro > CC: Wen Congyang > Signed-off-by: Yasuaki Ishimatsu > > --- > drivers/base/memory.c | 20 ++++++++++++++++++++ > include/linux/memory.h | 1 + > mm/memory_hotplug.c | 5 +++++ > 3 files changed, 26 insertions(+) > > Index: linux-3.5-rc4/drivers/base/memory.c > =================================================================== > --- linux-3.5-rc4.orig/drivers/base/memory.c 2012-06-26 13:28:16.726211752 +0900 > +++ linux-3.5-rc4/drivers/base/memory.c 2012-06-26 13:34:22.423639904 +0900 > @@ -70,6 +70,26 @@ void unregister_memory_isolate_notifier( > } > EXPORT_SYMBOL(unregister_memory_isolate_notifier); > > +bool memory_is_offline(unsigned long start_pfn, unsigned long end_pfn) > +{ > + struct memory_block *mem; > + struct mem_section *section; > + unsigned long pfn, section_nr; > + > + for (pfn = start_pfn; pfn < end_pfn; pfn += PAGES_PER_SECTION) { > + section_nr = pfn_to_section_nr(pfn); > + section = __nr_to_section(section_nr); > + mem = find_memory_block(section); Seems find_memory_block_hinted() is more efficient than find_memory_block() here. > + if (!mem) > + continue; > + if (mem->state == MEM_OFFLINE) > + continue; > + return false; > + } > + > + return true; > +} > + > /* > * register_memory - Setup a sysfs device for a memory block > */ > Index: linux-3.5-rc4/include/linux/memory.h > =================================================================== > --- linux-3.5-rc4.orig/include/linux/memory.h 2012-06-25 04:53:04.000000000 +0900 > +++ linux-3.5-rc4/include/linux/memory.h 2012-06-26 13:34:22.424639891 +0900 > @@ -120,6 +120,7 @@ extern int memory_isolate_notify(unsigne > extern struct memory_block *find_memory_block_hinted(struct mem_section *, > struct memory_block *); > extern struct memory_block *find_memory_block(struct mem_section *); > +extern bool memory_is_offline(unsigned long start_pfn, unsigned long end_pfn); > #define CONFIG_MEM_BLOCK_SIZE (PAGES_PER_SECTION< enum mem_add_context { BOOT, HOTPLUG }; > #endif /* CONFIG_MEMORY_HOTPLUG_SPARSE */ > Index: linux-3.5-rc4/mm/memory_hotplug.c > =================================================================== > --- linux-3.5-rc4.orig/mm/memory_hotplug.c 2012-06-26 13:28:16.743211538 +0900 > +++ linux-3.5-rc4/mm/memory_hotplug.c 2012-06-26 13:48:38.264940468 +0900 > @@ -887,6 +887,11 @@ static int __ref offline_pages(unsigned > > lock_memory_hotplug(); > > + if (memory_is_offline(start_pfn, end_pfn)) { > + ret = 0; > + goto out; > + } > + > zone = page_zone(pfn_to_page(start_pfn)); > node = zone_to_nid(zone); > nr_pages = end_pfn - start_pfn; > > -- > To unsubscribe from this list: send the line "unsubscribe linux-acpi" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- 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/