Messages in this thread Patch in this message | | | Date | Mon, 27 Sep 2010 14:23:49 -0500 | From | Nathan Fontenot <> | Subject | [PATCH 3/8] v2 Add mutex for adding/removing memory blocks |
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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-next/drivers/base/memory.c =================================================================== --- linux-next.orig/drivers/base/memory.c 2010-09-27 09:31:35.000000000 -0500 +++ linux-next/drivers/base/memory.c 2010-09-27 09:31:57.000000000 -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 = { @@ -476,6 +478,8 @@ if (!mem) return -ENOMEM; + mutex_lock(&mem_sysfs_mutex); + mem->phys_index = __section_nr(section); mem->state = state; atomic_inc(&mem->section_count); @@ -497,6 +501,7 @@ ret = register_mem_sect_under_node(mem, nid); } + mutex_unlock(&mem_sysfs_mutex); return ret; } @@ -505,6 +510,7 @@ { struct memory_block *mem; + mutex_lock(&mem_sysfs_mutex); mem = find_memory_block(section); if (atomic_dec_and_test(&mem->section_count)) { @@ -516,6 +522,7 @@ unregister_memory(mem, section); } + mutex_unlock(&mem_sysfs_mutex); return 0; }
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