On 2014/8/11 15:18, 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 added to > which zone, and we don't need to know the above two limits. > > Updated the related Documentation. > > Signed-off-by: Zhang Zhen <zhenzhang.zhang@xxxxxxxxxx> > --- > Documentation/ABI/testing/sysfs-devices-memory | 10 +++++ > Documentation/memory-hotplug.txt | 4 +- > drivers/base/memory.c | 62 +++++++++++++++++++++++++- > include/linux/memory_hotplug.h | 1 + > mm/memory_hotplug.c | 4 +- > 5 files changed, 77 insertions(+), 4 deletions(-) > > diff --git a/Documentation/ABI/testing/sysfs-devices-memory b/Documentation/ABI/testing/sysfs-devices-memory > index 7405de2..0e58924 100644 > --- a/Documentation/ABI/testing/sysfs-devices-memory > +++ b/Documentation/ABI/testing/sysfs-devices-memory > @@ -61,6 +61,16 @@ Users: hotplug memory remove tools > http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils > > > +What: /sys/devices/system/memory/memoryX/zone_to_online > +Date: July 2014 > +Contact: Zhang Zhen <zhenzhang.zhang@xxxxxxxxxx> > +Description: > + The file /sys/devices/system/memory/memoryX/zone_to_online > + is read-only and is designed to show which zone this memory block can > + be onlined to. > +Users: hotplug memory remove tools > + http://www.ibm.com/developerworks/wikis/display/LinuxP/powerpc-utils > + > What: /sys/devices/system/memoryX/nodeY > Date: October 2009 > Contact: Linux Memory Management list <linux-mm@xxxxxxxxx> > diff --git a/Documentation/memory-hotplug.txt b/Documentation/memory-hotplug.txt > index 45134dc..09e3d37 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/zone_to_online > > '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. > +'zone_to_online' : 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..044353c 100644 > --- a/drivers/base/memory.c > +++ b/drivers/base/memory.c > @@ -373,11 +373,70 @@ static ssize_t show_phys_device(struct device *dev, > return sprintf(buf, "%d\n", mem->phys_device); > } > > +static ssize_t show_zone_to_online(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, *zone_next; > + > + first_page = pfn_to_page(mem->start_section_nr << PFN_SECTION_SHIFT); > + start_pfn = page_to_pfn(first_page); > + end_pfn = start_pfn + nr_pages; > + > + /*The block contains more than one zone can not be offlined.*/ > + if (!test_pages_in_a_zone(start_pfn, end_pfn)) > + return sprintf(buf, "NULL\n"); > + > + zone = page_zone(first_page); > + > + /*The mem block is the last block of memory.*/ > + if (!pfn_valid(end_pfn + 1)) { > +#ifdef CONFIG_HIGHMEM > + if (zone_idx(zone) == ZONE_HIGHMEM) > + return sprintf(buf, "%s %s\n", zone->name, (zone + 1)->name); > +#else > + if (zone_idx(zone) == ZONE_NORMAL) > + 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)) { > + 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); > + } else > + return sprintf(buf, "%s %s\n", zone->name, (zone - 1)->name); > + } > + return sprintf(buf, "%s\n", zone->name); > + > + } > + > + zone_next = page_zone(first_page + nr_pages + 1); > +#ifdef CONFIG_HIGHMEM > + if (zone_idx(zone) == ZONE_HIGHMEM && zone_idx(zone_next) == ZONE_MOVABLE) > + return sprintf(buf, "%s %s\n", zone->name, zone_next->name); > +#else > + if (zone_idx(zone) == ZONE_NORMAL && zone_idx(zone_next) == ZONE_MOVABLE) > + return sprintf(buf, "%s %s\n", zone->name, zone_next->name); > +#endif > + if (zone_idx(zone) == ZONE_MOVABLE) { > + if (pfn_valid(start_pfn - nr_pages)) { > + 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); > + } else > + 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(zone_to_online, 0444, show_zone_to_online, NULL); > /* > * Block size attribute stuff > */ > @@ -523,6 +582,7 @@ static struct attribute *memory_memblk_attrs[] = { > &dev_attr_state.attr, > &dev_attr_phys_device.attr, > &dev_attr_removable.attr, > + &dev_attr_zone_to_online.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..785b7e6 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; > @@ -1638,7 +1638,7 @@ static void node_states_clear_node(int node, struct memory_notify *arg) > node_clear_state(node, N_MEMORY); > } > > -static int __ref __offline_pages(unsigned long start_pfn, > +int __ref __offline_pages(unsigned long start_pfn, Sorry, here is needless, i will remove it in next version. > unsigned long end_pfn, unsigned long timeout) > { > unsigned long pfn, nr_pages, expire; 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