From 54f23eb7ba7619de85d8edca6e5336bc33072dbd Mon Sep 17 00:00:00 2001 From: Nathan Fontenot Date: Mon, 26 Sep 2011 10:22:33 -0500 Subject: [PATCH] memory hotplug: Correct page reservation checking The check to ensure that pages of recently added memory sections are correctly marked as reserved before trying to online the memory is broken. The request to online the memory fails with the following: kernel: section number XXX page number 256 not reserved, was it already online? This updates the page reservation checking to check the pages of each memory section of the memory block being onlined individually. Signed-off-by: Nathan Fontenot Signed-off-by: Greg Kroah-Hartman --- drivers/base/memory.c | 60 ++++++++++++++++++++++++++----------------- 1 file changed, 37 insertions(+), 23 deletions(-) diff --git a/drivers/base/memory.c b/drivers/base/memory.c index 2a0b5f1020ed..ca8bfe59ae32 100644 --- a/drivers/base/memory.c +++ b/drivers/base/memory.c @@ -227,41 +227,42 @@ int memory_isolate_notify(unsigned long val, void *v) * MEMORY_HOTPLUG depends on SPARSEMEM in mm/Kconfig, so it is * OK to have direct references to sparsemem variables in here. */ +static int check_page_reservations(unsigned long phys_index) +{ + int i; + struct page *page; + + page = pfn_to_page(phys_index << PFN_SECTION_SHIFT); + + for (i = 0; i < PAGES_PER_SECTION; i++) { + if (PageReserved(page + i)) + continue; + + printk(KERN_WARNING "section number %ld page number %d " + "not reserved, was it already online?\n", phys_index, i); + return -EBUSY; + } + + return 0; +} + static int memory_block_action(unsigned long phys_index, unsigned long action) { - int i; unsigned long start_pfn, start_paddr; unsigned long nr_pages = PAGES_PER_SECTION * sections_per_block; - struct page *first_page; + struct page *page; int ret; - first_page = pfn_to_page(phys_index << PFN_SECTION_SHIFT); - - /* - * The probe routines leave the pages reserved, just - * as the bootmem code does. Make sure they're still - * that way. - */ - if (action == MEM_ONLINE) { - for (i = 0; i < nr_pages; i++) { - if (PageReserved(first_page+i)) - continue; - - printk(KERN_WARNING "section number %ld page number %d " - "not reserved, was it already online?\n", - phys_index, i); - return -EBUSY; - } - } + page = pfn_to_page(phys_index << PFN_SECTION_SHIFT); switch (action) { case MEM_ONLINE: - start_pfn = page_to_pfn(first_page); + start_pfn = page_to_pfn(page); ret = online_pages(start_pfn, nr_pages); break; case MEM_OFFLINE: - start_paddr = page_to_pfn(first_page) << PAGE_SHIFT; + start_paddr = page_to_pfn(page) << PAGE_SHIFT; ret = remove_memory(start_paddr, nr_pages << PAGE_SHIFT); break; @@ -277,7 +278,7 @@ memory_block_action(unsigned long phys_index, unsigned long action) static int memory_block_change_state(struct memory_block *mem, unsigned long to_state, unsigned long from_state_req) { - int ret = 0; + int i, ret = 0; mutex_lock(&mem->state_mutex); @@ -289,6 +290,19 @@ static int memory_block_change_state(struct memory_block *mem, if (to_state == MEM_OFFLINE) mem->state = MEM_GOING_OFFLINE; + if (to_state == MEM_ONLINE) { + /* + * The probe routines leave the pages reserved, just + * as the bootmem code does. Make sure they're still + * that way. + */ + for (i = 0; i < sections_per_block; i++) { + ret = check_page_reservations(mem->start_section_nr + i); + if (ret) + return ret; + } + } + ret = memory_block_action(mem->start_section_nr, to_state); if (ret) -- 2.39.5