From ea01ea937dcae2caa146dea1918cccf2f16ed3c4 Mon Sep 17 00:00:00 2001 From: Badari Pulavarty Date: Mon, 28 Apr 2008 02:12:01 -0700 Subject: 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 Acked-by: Yasunori Goto Cc: Benjamin Herrenschmidt Cc: Paul Mackerras Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- mm/sparse.c | 45 ++++++++++++++++++++++++++++++++++++++++++--- 1 file changed, 42 insertions(+), 3 deletions(-) (limited to 'mm/sparse.c') diff --git a/mm/sparse.c b/mm/sparse.c index 7e9191381f86..186a85bf7912 100644 --- a/mm/sparse.c +++ b/mm/sparse.c @@ -208,12 +208,13 @@ static unsigned long sparse_encode_mem_map(struct page *mem_map, unsigned long p } /* - * We need this if we ever free the mem_maps. While not implemented yet, - * this function is included for parity with its sibling. + * Decode mem_map from the coded memmap */ -static __attribute((unused)) +static struct page *sparse_decode_mem_map(unsigned long coded_mem_map, unsigned long pnum) { + /* mask off the extra low bits of information */ + coded_mem_map &= SECTION_MAP_MASK; return ((struct page *)coded_mem_map) + section_nr_to_pfn(pnum); } @@ -404,6 +405,28 @@ static void __kfree_section_memmap(struct page *memmap, unsigned long nr_pages) } #endif /* CONFIG_SPARSEMEM_VMEMMAP */ +static void free_section_usemap(struct page *memmap, unsigned long *usemap) +{ + if (!usemap) + return; + + /* + * Check to see if allocation came from hot-plug-add + */ + if (PageSlab(virt_to_page(usemap))) { + kfree(usemap); + if (memmap) + __kfree_section_memmap(memmap, PAGES_PER_SECTION); + return; + } + + /* + * TODO: Allocations came from bootmem - how do I free up ? + */ + printk(KERN_WARNING "Not freeing up allocations from bootmem " + "- leaking memory\n"); +} + /* * returns the number of sections whose mem_maps were properly * set. If this is <=0, then that means that the passed-in @@ -456,4 +479,20 @@ out: } return ret; } + +void sparse_remove_one_section(struct zone *zone, struct mem_section *ms) +{ + struct page *memmap = NULL; + unsigned long *usemap = NULL; + + if (ms->section_mem_map) { + usemap = ms->pageblock_flags; + memmap = sparse_decode_mem_map(ms->section_mem_map, + __section_nr(ms)); + ms->section_mem_map = 0; + ms->pageblock_flags = NULL; + } + + free_section_usemap(memmap, usemap); +} #endif -- cgit v1.2.3