From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752836Ab2LDJb5 (ORCPT ); Tue, 4 Dec 2012 04:31:57 -0500 Received: from cn.fujitsu.com ([222.73.24.84]:3809 "EHLO song.cn.fujitsu.com" rhost-flags-OK-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1751554Ab2LDJbw (ORCPT ); Tue, 4 Dec 2012 04:31:52 -0500 X-IronPort-AV: E=Sophos;i="4.83,370,1352044800"; d="scan'208";a="6330005" Message-ID: <50BDC2CB.2030802@cn.fujitsu.com> Date: Tue, 04 Dec 2012 17:30:51 +0800 From: Tang Chen User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:12.0) Gecko/20120430 Thunderbird/12.0.1 MIME-Version: 1.0 To: Wen Congyang CC: x86@kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-acpi@vger.kernel.org, linux-s390@vger.kernel.org, linux-sh@vger.kernel.org, linux-ia64@vger.kernel.org, cmetcalf@tilera.com, sparclinux@vger.kernel.org, David Rientjes , Jiang Liu , Len Brown , benh@kernel.crashing.org, paulus@samba.org, Christoph Lameter , Minchan Kim , Andrew Morton , KOSAKI Motohiro , Yasuaki Ishimatsu , Jianguo Wu Subject: Re: [Patch v4 05/12] memory-hotplug: introduce new function arch_remove_memory() for removing page table depends on architecture References: <1354010422-19648-1-git-send-email-wency@cn.fujitsu.com> <1354010422-19648-6-git-send-email-wency@cn.fujitsu.com> In-Reply-To: <1354010422-19648-6-git-send-email-wency@cn.fujitsu.com> X-MIMETrack: Itemize by SMTP Server on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/12/04 17:31:12, Serialize by Router on mailserver/fnst(Release 8.5.3|September 15, 2011) at 2012/12/04 17:31:13, Serialize complete at 2012/12/04 17:31:13 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=ISO-8859-1; format=flowed Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 11/27/2012 06:00 PM, Wen Congyang wrote: > For removing memory, we need to remove page table. But it depends > on architecture. So the patch introduce arch_remove_memory() for > removing page table. Now it only calls __remove_pages(). > > Note: __remove_pages() for some archtecuture is not implemented > (I don't know how to implement it for s390). > > CC: David Rientjes > CC: Jiang Liu > CC: Len Brown > CC: Benjamin Herrenschmidt > CC: Paul Mackerras > CC: Christoph Lameter > Cc: Minchan Kim > CC: Andrew Morton > CC: KOSAKI Motohiro > CC: Yasuaki Ishimatsu > Signed-off-by: Wen Congyang > --- > arch/ia64/mm/init.c | 18 ++++++++++++++++++ > arch/powerpc/mm/mem.c | 12 ++++++++++++ > arch/s390/mm/init.c | 12 ++++++++++++ > arch/sh/mm/init.c | 17 +++++++++++++++++ > arch/tile/mm/init.c | 8 ++++++++ > arch/x86/mm/init_32.c | 12 ++++++++++++ > arch/x86/mm/init_64.c | 15 +++++++++++++++ > include/linux/memory_hotplug.h | 1 + > mm/memory_hotplug.c | 2 ++ > 9 files changed, 97 insertions(+) > > diff --git a/arch/ia64/mm/init.c b/arch/ia64/mm/init.c > index 082e383..e333822 100644 > --- a/arch/ia64/mm/init.c > +++ b/arch/ia64/mm/init.c > @@ -689,6 +689,24 @@ int arch_add_memory(int nid, u64 start, u64 size) > > return ret; > } > + > +#ifdef CONFIG_MEMORY_HOTREMOVE > +int arch_remove_memory(u64 start, u64 size) > +{ > + unsigned long start_pfn = start>> PAGE_SHIFT; > + unsigned long nr_pages = size>> PAGE_SHIFT; > + struct zone *zone; > + int ret; > + > + zone = page_zone(pfn_to_page(start_pfn)); > + ret = __remove_pages(zone, start_pfn, nr_pages); > + if (ret) > + pr_warn("%s: Problem encountered in __remove_pages() as" > + " ret=%d\n", __func__, ret); > + > + return ret; Just a little question, why do we have different handlers for ret on different platforms ? Sometimes we print a msg, sometimes we just return, and sometimes we give a WARN_ON(). But no big deal. :) Reviewed-by: Tang Chen > +} > +#endif > #endif > > /* > diff --git a/arch/powerpc/mm/mem.c b/arch/powerpc/mm/mem.c > index 0dba506..09c6451 100644 > --- a/arch/powerpc/mm/mem.c > +++ b/arch/powerpc/mm/mem.c > @@ -133,6 +133,18 @@ int arch_add_memory(int nid, u64 start, u64 size) > > return __add_pages(nid, zone, start_pfn, nr_pages); > } > + > +#ifdef CONFIG_MEMORY_HOTREMOVE > +int arch_remove_memory(u64 start, u64 size) > +{ > + unsigned long start_pfn = start>> PAGE_SHIFT; > + unsigned long nr_pages = size>> PAGE_SHIFT; > + struct zone *zone; > + > + zone = page_zone(pfn_to_page(start_pfn)); > + return __remove_pages(zone, start_pfn, nr_pages); > +} > +#endif > #endif /* CONFIG_MEMORY_HOTPLUG */ > > /* > diff --git a/arch/s390/mm/init.c b/arch/s390/mm/init.c > index 81e596c..b565190 100644 > --- a/arch/s390/mm/init.c > +++ b/arch/s390/mm/init.c > @@ -257,4 +257,16 @@ int arch_add_memory(int nid, u64 start, u64 size) > vmem_remove_mapping(start, size); > return rc; > } > + > +#ifdef CONFIG_MEMORY_HOTREMOVE > +int arch_remove_memory(u64 start, u64 size) > +{ > + /* > + * There is no hardware or firmware interface which could trigger a > + * hot memory remove on s390. So there is nothing that needs to be > + * implemented. > + */ > + return -EBUSY; > +} > +#endif > #endif /* CONFIG_MEMORY_HOTPLUG */ > diff --git a/arch/sh/mm/init.c b/arch/sh/mm/init.c > index 82cc576..1057940 100644 > --- a/arch/sh/mm/init.c > +++ b/arch/sh/mm/init.c > @@ -558,4 +558,21 @@ int memory_add_physaddr_to_nid(u64 addr) > EXPORT_SYMBOL_GPL(memory_add_physaddr_to_nid); > #endif > > +#ifdef CONFIG_MEMORY_HOTREMOVE > +int arch_remove_memory(u64 start, u64 size) > +{ > + unsigned long start_pfn = start>> PAGE_SHIFT; > + unsigned long nr_pages = size>> PAGE_SHIFT; > + struct zone *zone; > + int ret; > + > + zone = page_zone(pfn_to_page(start_pfn)); > + ret = __remove_pages(zone, start_pfn, nr_pages); > + if (unlikely(ret)) > + pr_warn("%s: Failed, __remove_pages() == %d\n", __func__, > + ret); > + > + return ret; > +} > +#endif > #endif /* CONFIG_MEMORY_HOTPLUG */ > diff --git a/arch/tile/mm/init.c b/arch/tile/mm/init.c > index ef29d6c..2749515 100644 > --- a/arch/tile/mm/init.c > +++ b/arch/tile/mm/init.c > @@ -935,6 +935,14 @@ int remove_memory(u64 start, u64 size) > { > return -EINVAL; > } > + > +#ifdef CONFIG_MEMORY_HOTREMOVE > +int arch_remove_memory(u64 start, u64 size) > +{ > + /* TODO */ > + return -EBUSY; > +} > +#endif > #endif > > struct kmem_cache *pgd_cache; > diff --git a/arch/x86/mm/init_32.c b/arch/x86/mm/init_32.c > index 11a5800..b19eba4 100644 > --- a/arch/x86/mm/init_32.c > +++ b/arch/x86/mm/init_32.c > @@ -839,6 +839,18 @@ int arch_add_memory(int nid, u64 start, u64 size) > > return __add_pages(nid, zone, start_pfn, nr_pages); > } > + > +#ifdef CONFIG_MEMORY_HOTREMOVE > +int arch_remove_memory(u64 start, u64 size) > +{ > + unsigned long start_pfn = start>> PAGE_SHIFT; > + unsigned long nr_pages = size>> PAGE_SHIFT; > + struct zone *zone; > + > + zone = page_zone(pfn_to_page(start_pfn)); > + return __remove_pages(zone, start_pfn, nr_pages); > +} > +#endif > #endif > > /* > diff --git a/arch/x86/mm/init_64.c b/arch/x86/mm/init_64.c > index 3baff25..5675335 100644 > --- a/arch/x86/mm/init_64.c > +++ b/arch/x86/mm/init_64.c > @@ -680,6 +680,21 @@ int arch_add_memory(int nid, u64 start, u64 size) > } > EXPORT_SYMBOL_GPL(arch_add_memory); > > +#ifdef CONFIG_MEMORY_HOTREMOVE > +int __ref arch_remove_memory(u64 start, u64 size) > +{ > + unsigned long start_pfn = start>> PAGE_SHIFT; > + unsigned long nr_pages = size>> PAGE_SHIFT; > + struct zone *zone; > + int ret; > + > + zone = page_zone(pfn_to_page(start_pfn)); > + ret = __remove_pages(zone, start_pfn, nr_pages); > + WARN_ON_ONCE(ret); > + > + return ret; > +} > +#endif > #endif /* CONFIG_MEMORY_HOTPLUG */ > > static struct kcore_list kcore_vsyscall; > diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h > index 38675e9..191b2d9 100644 > --- a/include/linux/memory_hotplug.h > +++ b/include/linux/memory_hotplug.h > @@ -85,6 +85,7 @@ extern void __online_page_free(struct page *page); > > #ifdef CONFIG_MEMORY_HOTREMOVE > extern bool is_pageblock_removable_nolock(struct page *page); > +extern int arch_remove_memory(u64 start, u64 size); > #endif /* CONFIG_MEMORY_HOTREMOVE */ > > /* reasonably generic interface to expand the physical pages in a zone */ > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 63d5388..e741732 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1111,6 +1111,8 @@ repeat: > /* remove memmap entry */ > firmware_map_remove(start, start + size, "System RAM"); > > + arch_remove_memory(start, size); > + > unlock_memory_hotplug(); > > return 0;