Messages in this thread Patch in this message | | | Date | Mon, 09 Aug 2010 13:38:46 -0500 | From | Nathan Fontenot <> | Subject | [PATCH 4/8] v5 Add mutex for add/remove of memory blocks |
| |
Add a new mutex for use in adding and removing of memory blocks. This is needed to avoid any race conditions in which the same memory block could be added and removed at the same time.
Signed-off-by: Nathan Fontenot <nfont@austin.ibm.com>
--- drivers/base/memory.c | 7 +++++++ 1 file changed, 7 insertions(+)
Index: linux-2.6/drivers/base/memory.c =================================================================== --- linux-2.6.orig/drivers/base/memory.c 2010-08-09 07:49:04.000000000 -0500 +++ linux-2.6/drivers/base/memory.c 2010-08-09 07:50:20.000000000 -0500 @@ -27,6 +27,8 @@ #include <asm/atomic.h> #include <asm/uaccess.h> +static DEFINE_MUTEX(mem_sysfs_mutex); + #define MEMORY_CLASS_NAME "memory" static struct sysdev_class memory_sysdev_class = { @@ -485,6 +487,8 @@ static int add_memory_block(int nid, str if (!mem) return -ENOMEM; + mutex_lock(&mem_sysfs_mutex); + mem->start_phys_index = __section_nr(section); mem->state = state; atomic_inc(&mem->section_count); @@ -508,6 +512,7 @@ static int add_memory_block(int nid, str ret = register_mem_sect_under_node(mem, nid); } + mutex_unlock(&mem_sysfs_mutex); return ret; } @@ -516,6 +521,7 @@ int remove_memory_block(unsigned long no { struct memory_block *mem; + mutex_lock(&mem_sysfs_mutex); mem = find_memory_block(section); if (atomic_dec_and_test(&mem->section_count)) { @@ -528,6 +534,7 @@ int remove_memory_block(unsigned long no unregister_memory(mem, section); } + mutex_unlock(&mem_sysfs_mutex); return 0; }
| |