This patch introduce new mm_down/up*() operation which will run on mmap_sem as a semaphore or as a range lock depending on CONFIG_MEM_RANGE_LOCK.
When CONFIG_MEM_RANGE_LOCK is defined, the additional range parameter is used, otherwise it is ignored to avoid any useless additional stack parameter. Signed-off-by: Laurent Dufour <[email protected]> --- include/linux/mm.h | 27 +++++++++++++++++++++++++++ include/linux/mm_types.h | 5 +++++ 2 files changed, 32 insertions(+) diff --git a/include/linux/mm.h b/include/linux/mm.h index b09048386152..d47b28eb0a53 100644 --- a/include/linux/mm.h +++ b/include/linux/mm.h @@ -15,6 +15,7 @@ #include <linux/debug_locks.h> #include <linux/mm_types.h> #include <linux/range.h> +#include <linux/range_lock.h> #include <linux/pfn.h> #include <linux/percpu-refcount.h> #include <linux/bit_spinlock.h> @@ -2588,5 +2589,31 @@ void __init setup_nr_node_ids(void); static inline void setup_nr_node_ids(void) {} #endif +#ifdef CONFIG_MEM_RANGE_LOCK +#define mm_range_define(r) \ + struct range_lock r = __RANGE_LOCK_INITIALIZER(0, RANGE_LOCK_FULL) +#define mm_read_lock(m, r) range_read_lock(&(m)->mmap_sem, r) +#define mm_read_trylock(m, r) range_read_trylock(&(m)->mmap_sem, r) +#define mm_read_unlock(m, r) range_read_unlock(&(m)->mmap_sem, r) +#define mm_write_lock(m, r) range_write_lock(&(m)->mmap_sem, r) +#define mm_write_trylock(m, r) range_write_trylock(&(m)->mmap_sem, r) +#define mm_write_unlock(m, r) range_write_unlock(&(m)->mmap_sem, r) +#define mm_write_lock_killable(m, r) \ + range_write_lock_interruptible(&(m)->mmap_sem, r) +#define mm_downgrade_write(m, r) range_downgrade_write(&(m)->mmap_sem, r) + +#else /* CONFIG_MEM_RANGE_LOCK */ +#define mm_range_define(r) do { } while (0) +#define mm_read_lock(m, r) down_read(&(m)->mmap_sem) +#define mm_read_trylock(m, r) down_read_trylock(&(m)->mmap_sem) +#define mm_read_unlock(m, r) up_read(&(m)->mmap_sem) +#define mm_write_lock(m, r) down_write(&(m)->mmap_sem) +#define mm_write_trylock(m, r) down_write_trylock(&(m)->mmap_sem) +#define mm_write_unlock(m, r) up_write(&(m)->mmap_sem) +#define mm_write_lock_killable(m, r) down_write_killable(&(m)->mmap_sem) +#define mm_downgrade_write(m, r) downgrade_write(&(m)->mmap_sem) + +#endif /* CONFIG_MEM_RANGE_LOCK */ + #endif /* __KERNEL__ */ #endif /* _LINUX_MM_H */ diff --git a/include/linux/mm_types.h b/include/linux/mm_types.h index 45cdb27791a3..d40611490200 100644 --- a/include/linux/mm_types.h +++ b/include/linux/mm_types.h @@ -8,6 +8,7 @@ #include <linux/spinlock.h> #include <linux/rbtree.h> #include <linux/rwsem.h> +#include <linux/range_lock.h> #include <linux/completion.h> #include <linux/cpumask.h> #include <linux/uprobes.h> @@ -403,7 +404,11 @@ struct mm_struct { int map_count; /* number of VMAs */ spinlock_t page_table_lock; /* Protects page tables and some counters */ +#ifdef CONFIG_MEM_RANGE_LOCK + struct range_lock_tree mmap_sem; +#else struct rw_semaphore mmap_sem; +#endif struct list_head mmlist; /* List of maybe swapped mm's. These are globally strung * together off init_mm.mmlist, and are protected -- 2.7.4
