Messages in this thread | | | Date | Tue, 19 Aug 2014 19:42:27 +0900 | From | Yasuaki Ishimatsu <> | Subject | Re: [PATCH v2] memory-hotplug: add sysfs zones_online_to attribute |
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(2014/08/19 16:35), Zhang Zhen wrote: > On 2014/8/18 14:11, Yasuaki Ishimatsu wrote: >> (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 <zhenzhang.zhang@huawei.com> >>> --- >>> 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 <zhenzhang.zhang@huawei.com> >>> +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 <linux-mm@kvack.org> >>> 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 >> > You are right, it is not enough. >
> Here we should make a check as follows. > if ((end_pfn + 1) > zone_end_pfn(page_zone(first_page))) > return 1; > I will send a patch to fix it.
It's looks good to me.
Thanks, Yasuaki Ishimatsu
> > Thanks ! >> >>> + 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: <a href=mailto:"dont@kvack.org"> email@kvack.org </a> >> >> . >> > >
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