Add a section count property to the memory_block struct to track the number of memory sections that have been added/removed from a memory block. Updated to use atomic_dec_and_test(). Signed-off-by: Nathan Fontenot <nfont@xxxxxxxxxxxxxx> --- drivers/base/memory.c | 18 +++++++++++------- include/linux/memory.h | 2 ++ 2 files changed, 13 insertions(+), 7 deletions(-) Index: linux-2.6/drivers/base/memory.c =================================================================== --- linux-2.6.orig/drivers/base/memory.c 2010-07-20 06:38:21.000000000 -0500 +++ linux-2.6/drivers/base/memory.c 2010-07-20 06:43:29.000000000 -0500 @@ -487,6 +487,7 @@ static int add_memory_block(int nid, str mem->start_phys_index = __section_nr(section); mem->state = state; + atomic_inc(&mem->section_count); mutex_init(&mem->state_mutex); start_pfn = section_nr_to_pfn(mem->start_phys_index); mem->phys_device = arch_get_memory_phys_device(start_pfn); @@ -516,13 +517,16 @@ int remove_memory_block(unsigned long no struct memory_block *mem; mem = find_memory_block(section); - unregister_mem_sect_under_nodes(mem); - mem_remove_simple_file(mem, phys_index); - mem_remove_simple_file(mem, end_phys_index); - mem_remove_simple_file(mem, state); - mem_remove_simple_file(mem, phys_device); - mem_remove_simple_file(mem, removable); - unregister_memory(mem, section); + + if (atomic_dec_and_test(&mem->section_count)) { + unregister_mem_sect_under_nodes(mem); + mem_remove_simple_file(mem, phys_index); + mem_remove_simple_file(mem, end_phys_index); + mem_remove_simple_file(mem, state); + mem_remove_simple_file(mem, phys_device); + mem_remove_simple_file(mem, removable); + unregister_memory(mem, section); + } return 0; } Index: linux-2.6/include/linux/memory.h =================================================================== --- linux-2.6.orig/include/linux/memory.h 2010-07-20 06:35:38.000000000 -0500 +++ linux-2.6/include/linux/memory.h 2010-07-20 06:38:59.000000000 -0500 @@ -19,11 +19,13 @@ #include <linux/node.h> #include <linux/compiler.h> #include <linux/mutex.h> +#include <asm/atomic.h> struct memory_block { unsigned long start_phys_index; unsigned long end_phys_index; unsigned long state; + atomic_t section_count; /* * This serializes all state change requests. It isn't * held during creation because the control files are -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxxx For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>