diff options
| author | Badari Pulavarty <pbadari@us.ibm.com> | 2008-04-28 02:12:01 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2008-04-28 08:58:17 -0700 |
| commit | ea01ea937dcae2caa146dea1918cccf2f16ed3c4 (patch) | |
| tree | aa3189d587dc04f75bd6a0d79d7f5a764200cd81 /mm/memory_hotplug.c | |
| parent | 2a4e2b8780c6df42b19c053243dada7fa4d311ee (diff) | |
hotplug memory remove: generic __remove_pages() support
Generic helper function to remove section mappings and sysfs entries for the
section of the memory we are removing. offline_pages() correctly adjusted
zone and marked the pages reserved.
TODO: Yasunori Goto is working on patches to free up allocations from bootmem.
Signed-off-by: Badari Pulavarty <pbadari@us.ibm.com>
Acked-by: Yasunori Goto <y-goto@jp.fujitsu.com>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'mm/memory_hotplug.c')
| -rw-r--r-- | mm/memory_hotplug.c | 55 |
1 files changed, 55 insertions, 0 deletions
diff --git a/mm/memory_hotplug.c b/mm/memory_hotplug.c index 0fb330271271..d5094929766d 100644 --- a/mm/memory_hotplug.c +++ b/mm/memory_hotplug.c @@ -101,6 +101,25 @@ static int __add_section(struct zone *zone, unsigned long phys_start_pfn) return register_new_memory(__pfn_to_section(phys_start_pfn)); } +static int __remove_section(struct zone *zone, struct mem_section *ms) +{ + unsigned long flags; + struct pglist_data *pgdat = zone->zone_pgdat; + int ret = -EINVAL; + + if (!valid_section(ms)) + return ret; + + ret = unregister_memory_section(ms); + if (ret) + return ret; + + pgdat_resize_lock(pgdat, &flags); + sparse_remove_one_section(zone, ms); + pgdat_resize_unlock(pgdat, &flags); + return 0; +} + /* * Reasonably generic function for adding memory. It is * expected that archs that support memory hotplug will @@ -134,6 +153,42 @@ int __add_pages(struct zone *zone, unsigned long phys_start_pfn, } EXPORT_SYMBOL_GPL(__add_pages); +/** + * __remove_pages() - remove sections of pages from a zone + * @zone: zone from which pages need to be removed + * @phys_start_pfn: starting pageframe (must be aligned to start of a section) + * @nr_pages: number of pages to remove (must be multiple of section size) + * + * Generic helper function to remove section mappings and sysfs entries + * for the section of the memory we are removing. Caller needs to make + * sure that pages are marked reserved and zones are adjust properly by + * calling offline_pages(). + */ +int __remove_pages(struct zone *zone, unsigned long phys_start_pfn, + unsigned long nr_pages) +{ + unsigned long i, ret = 0; + int sections_to_remove; + + /* + * We can only remove entire sections + */ + BUG_ON(phys_start_pfn & ~PAGE_SECTION_MASK); + BUG_ON(nr_pages % PAGES_PER_SECTION); + + release_mem_region(phys_start_pfn << PAGE_SHIFT, nr_pages * PAGE_SIZE); + + sections_to_remove = nr_pages / PAGES_PER_SECTION; + for (i = 0; i < sections_to_remove; i++) { + unsigned long pfn = phys_start_pfn + i*PAGES_PER_SECTION; + ret = __remove_section(zone, __pfn_to_section(pfn)); + if (ret) + break; + } + return ret; +} +EXPORT_SYMBOL_GPL(__remove_pages); + static void grow_zone_span(struct zone *zone, unsigned long start_pfn, unsigned long end_pfn) { |