From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pd0-f170.google.com (mail-pd0-f170.google.com [209.85.192.170]) by kanga.kvack.org (Postfix) with ESMTP id 8F2C66B0036 for ; Mon, 18 Aug 2014 02:12:51 -0400 (EDT) Received: by mail-pd0-f170.google.com with SMTP id g10so6787184pdj.15 for ; Sun, 17 Aug 2014 23:12:48 -0700 (PDT) Received: from fgwmail6.fujitsu.co.jp (fgwmail6.fujitsu.co.jp. [192.51.44.36]) by mx.google.com with ESMTPS id el1si20029499pbc.217.2014.08.17.23.12.41 for (version=TLSv1 cipher=RC4-SHA bits=128/128); Sun, 17 Aug 2014 23:12:41 -0700 (PDT) Received: from kw-mxq.gw.nic.fujitsu.com (unknown [10.0.237.131]) by fgwmail6.fujitsu.co.jp (Postfix) with ESMTP id 0ADB93EE0C3 for ; Mon, 18 Aug 2014 15:12:28 +0900 (JST) Received: from s4.gw.fujitsu.co.jp (s4.gw.fujitsu.co.jp [10.0.50.94]) by kw-mxq.gw.nic.fujitsu.com (Postfix) with ESMTP id 38E53AC02A4 for ; Mon, 18 Aug 2014 15:12:27 +0900 (JST) Received: from g01jpfmpwkw03.exch.g01.fujitsu.local (g01jpfmpwkw03.exch.g01.fujitsu.local [10.0.193.57]) by s4.gw.fujitsu.co.jp (Postfix) with ESMTP id D2B491DB8037 for ; Mon, 18 Aug 2014 15:12:26 +0900 (JST) Message-ID: <53F19919.1070908@jp.fujitsu.com> Date: Mon, 18 Aug 2014 15:11:37 +0900 From: Yasuaki Ishimatsu MIME-Version: 1.0 Subject: Re: [PATCH v2] memory-hotplug: add sysfs zones_online_to attribute References: <1407902811-4873-1-git-send-email-zhenzhang.zhang@huawei.com> <53EAE534.8030303@huawei.com> In-Reply-To: <53EAE534.8030303@huawei.com> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Zhang Zhen , Andrew Morton , Dave Hansen , David Rientjes , toshi.kani@hp.com, n-horiguchi@ah.jp.nec.com Cc: wangnan0@huawei.com, linux-kernel@vger.kernel.org, Linux MM (2014/08/13 13:10), Zhang Zhen wrote: > Currently memory-hotplug has two limits: > 1. If the memory block is in ZONE_NORMAL, you can change it to > ZONE_MOVABLE, but this memory block must be adjacent to ZONE_MOVABLE. > 2. If the memory block is in ZONE_MOVABLE, you can change it to > ZONE_NORMAL, but this memory block must be adjacent to ZONE_NORMAL. > > With this patch, we can easy to know a memory block can be onlined to > which zone, and don't need to know the above two limits. > > Updated the related Documentation. > > Change v1 -> v2: > - optimize the implementation following Dave Hansen's suggestion > > Signed-off-by: Zhang Zhen > --- > Documentation/ABI/testing/sysfs-devices-memory | 8 ++++ > Documentation/memory-hotplug.txt | 4 +- > drivers/base/memory.c | 62 ++++++++++++++++++++++++++ > include/linux/memory_hotplug.h | 1 + > mm/memory_hotplug.c | 2 +- > 5 files changed, 75 insertions(+), 2 deletions(-) > > diff --git a/Documentation/ABI/testing/sysfs-devices-memory b/Documentation/ABI/testing/sysfs-devices-memory > index 7405de2..2b2a1d7 100644 > --- a/Documentation/ABI/testing/sysfs-devices-memory > +++ b/Documentation/ABI/testing/sysfs-devices-memory > @@ -61,6 +61,14 @@ Users: hotplug memory remove tools > http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils > > > +What: /sys/devices/system/memory/memoryX/zones_online_to > +Date: July 2014 > +Contact: Zhang Zhen > +Description: > + The file /sys/devices/system/memory/memoryX/zones_online_to > + is read-only and is designed to show which zone this memory block can > + be onlined to. > + > What: /sys/devices/system/memoryX/nodeY > Date: October 2009 > Contact: Linux Memory Management list > diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt > index 45134dc..5b34e33 100644 > --- a/Documentation/memory-hotplug.txt > +++ b/Documentation/memory-hotplug.txt > @@ -155,6 +155,7 @@ Under each memory block, you can see 4 files: > /sys/devices/system/memory/memoryXXX/phys_device > /sys/devices/system/memory/memoryXXX/state > /sys/devices/system/memory/memoryXXX/removable > +/sys/devices/system/memory/memoryXXX/zones_online_to > > 'phys_index' : read-only and contains memory block id, same as XXX. > 'state' : read-write > @@ -170,6 +171,8 @@ Under each memory block, you can see 4 files: > block is removable and a value of 0 indicates that > it is not removable. A memory block is removable only if > every section in the block is removable. > +'zones_online_to' : read-only: designed to show which zone this memory block > + can be onlined to. > > NOTE: > These directories/files appear after physical memory hotplug phase. > @@ -408,7 +411,6 @@ node if necessary. > - allowing memory hot-add to ZONE_MOVABLE. maybe we need some switch like > sysctl or new control file. > - showing memory block and physical device relationship. > - - showing memory block is under ZONE_MOVABLE or not > - test and make it better memory offlining. > - support HugeTLB page migration and offlining. > - memmap removing at memory offline. > diff --git a/drivers/base/memory.c b/drivers/base/memory.c > index a2e13e2..b5d693f 100644 > --- a/drivers/base/memory.c > +++ b/drivers/base/memory.c > @@ -373,10 +373,71 @@ static ssize_t show_phys_device(struct device *dev, > return sprintf(buf, "%d\n", mem->phys_device); > } > > +static int __zones_online_to(unsigned long end_pfn, > + struct page *first_page, unsigned long nr_pages) > +{ > + struct zone *zone_next; > + > + /*The mem block is the last block of memory.*/ > + if (!pfn_valid(end_pfn + 1)) > + return 1; The check is not enough if memory has hole as follows: PFN 0x00 0xd0 0xe0 0xf0 +-------------+-------------+-------------+ zone type | Normal | hole | Normal | +-------------+-------------+-------------+ In this case, 0xd1 is invalid pfn. But __zones_online_to should return 0 since 0xe0-0xf0 is Normal zone. Thanks, Yasuaki Ishimatsu > + zone_next = page_zone(first_page + nr_pages); > + if (zone_idx(zone_next) == ZONE_MOVABLE) > + return 1; > + return 0; > +} > + > +static ssize_t show_zones_online_to(struct device *dev, > + struct device_attribute *attr, char *buf) > +{ > + struct memory_block *mem = to_memory_block(dev); > + unsigned long start_pfn, end_pfn; > + unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block; > + struct page *first_page; > + struct zone *zone, *zone_prev; > + > + start_pfn = section_nr_to_pfn(mem->start_section_nr); > + end_pfn = start_pfn + nr_pages; > + first_page = pfn_to_page(start_pfn); > + > + /*The block contains more than one zone can not be offlined.*/ > + if (!test_pages_in_a_zone(start_pfn, end_pfn)) > + return sprintf(buf, "none\n"); > + > + zone = page_zone(first_page); > + > +#ifdef CONFIG_HIGHMEM > + if (zone_idx(zone) == ZONE_HIGHMEM) { > + if (__zones_online_to(end_pfn, first_page, nr_pages)) > + return sprintf(buf, "%s %s\n", > + zone->name, (zone + 1)->name); > + } > +#else > + if (zone_idx(zone) == ZONE_NORMAL) { > + if (__zones_online_to(end_pfn, first_page, nr_pages)) > + return sprintf(buf, "%s %s\n", > + zone->name, (zone + 1)->name); > + } > +#endif > + > + if (zone_idx(zone) == ZONE_MOVABLE) { > + if (!pfn_valid(start_pfn - nr_pages)) > + return sprintf(buf, "%s %s\n", > + zone->name, (zone - 1)->name); > + zone_prev = page_zone(first_page - nr_pages); > + if (zone_idx(zone_prev) != ZONE_MOVABLE) > + return sprintf(buf, "%s %s\n", > + zone->name, (zone - 1)->name); > + } > + > + return sprintf(buf, "%s\n", zone->name); > +} > + > static DEVICE_ATTR(phys_index, 0444, show_mem_start_phys_index, NULL); > static DEVICE_ATTR(state, 0644, show_mem_state, store_mem_state); > static DEVICE_ATTR(phys_device, 0444, show_phys_device, NULL); > static DEVICE_ATTR(removable, 0444, show_mem_removable, NULL); > +static DEVICE_ATTR(zones_online_to, 0444, show_zones_online_to, NULL); > > /* > * Block size attribute stuff > @@ -523,6 +584,7 @@ static struct attribute *memory_memblk_attrs[] = { > &dev_attr_state.attr, > &dev_attr_phys_device.attr, > &dev_attr_removable.attr, > + &dev_attr_zones_online_to.attr, > NULL > }; > > diff --git a/include/linux/memory_hotplug.h b/include/linux/memory_hotplug.h > index d9524c4..8f1a419 100644 > --- a/include/linux/memory_hotplug.h > +++ b/include/linux/memory_hotplug.h > @@ -84,6 +84,7 @@ extern int zone_grow_waitqueues(struct zone *zone, unsigned long nr_pages); > extern int add_one_highpage(struct page *page, int pfn, int bad_ppro); > /* VM interface that may be used by firmware interface */ > extern int online_pages(unsigned long, unsigned long, int); > +extern int test_pages_in_a_zone(unsigned long, unsigned long); > extern void __offline_isolated_pages(unsigned long, unsigned long); > > typedef void (*online_page_callback_t)(struct page *page); > diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c > index 2ff8c23..29d8693 100644 > --- a/mm/memory_hotplug.c > +++ b/mm/memory_hotplug.c > @@ -1307,7 +1307,7 @@ int is_mem_section_removable(unsigned long start_pfn, unsigned long nr_pages) > /* > * Confirm all pages in a range [start, end) is belongs to the same zone. > */ > -static int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn) > +int test_pages_in_a_zone(unsigned long start_pfn, unsigned long end_pfn) > { > unsigned long pfn; > struct zone *zone = NULL; > -- 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