#include <linux/rcupdate.h>
#include <linux/smp.h>
#include <linux/trace_events.h>
+#include <linux/local_lock.h>
EXPORT_TRACEPOINT_SYMBOL(mmap_lock_start_locking);
EXPORT_TRACEPOINT_SYMBOL(mmap_lock_acquire_returned);
*/
#define CONTEXT_COUNT 4
-static DEFINE_PER_CPU(char __rcu *, memcg_path_buf);
+struct memcg_path {
+ local_lock_t lock;
+ char __rcu *buf;
+ local_t buf_idx;
+};
+static DEFINE_PER_CPU(struct memcg_path, memcg_paths) = {
+ .lock = INIT_LOCAL_LOCK(lock),
+ .buf_idx = LOCAL_INIT(0),
+};
+
static char **tmp_bufs;
-static DEFINE_PER_CPU(int, memcg_path_buf_idx);
/* Called with reg_lock held. */
static void free_memcg_path_bufs(void)
{
+ struct memcg_path *memcg_path;
int cpu;
char **old = tmp_bufs;
for_each_possible_cpu(cpu) {
- *(old++) = rcu_dereference_protected(
- per_cpu(memcg_path_buf, cpu),
+ memcg_path = per_cpu_ptr(&memcg_paths, cpu);
+ *(old++) = rcu_dereference_protected(memcg_path->buf,
lockdep_is_held(®_lock));
- rcu_assign_pointer(per_cpu(memcg_path_buf, cpu), NULL);
+ rcu_assign_pointer(memcg_path->buf, NULL);
}
/* Wait for inflight memcg_path_buf users to finish. */
new = kmalloc(MEMCG_PATH_BUF_SIZE * CONTEXT_COUNT, GFP_KERNEL);
if (new == NULL)
goto out_fail_free;
- rcu_assign_pointer(per_cpu(memcg_path_buf, cpu), new);
+ rcu_assign_pointer(per_cpu_ptr(&memcg_paths, cpu)->buf, new);
/* Don't need to wait for inflights, they'd have gotten NULL. */
}
static inline char *get_memcg_path_buf(void)
{
+ struct memcg_path *memcg_path = this_cpu_ptr(&memcg_paths);
char *buf;
int idx;
rcu_read_lock();
- buf = rcu_dereference(*this_cpu_ptr(&memcg_path_buf));
+ buf = rcu_dereference(memcg_path->buf);
if (buf == NULL) {
rcu_read_unlock();
return NULL;
}
- idx = this_cpu_add_return(memcg_path_buf_idx, MEMCG_PATH_BUF_SIZE) -
+ idx = local_add_return(MEMCG_PATH_BUF_SIZE, &memcg_path->buf_idx) -
MEMCG_PATH_BUF_SIZE;
return &buf[idx];
}
static inline void put_memcg_path_buf(void)
{
- this_cpu_sub(memcg_path_buf_idx, MEMCG_PATH_BUF_SIZE);
+ local_sub(MEMCG_PATH_BUF_SIZE, &this_cpu_ptr(&memcg_paths)->buf_idx);
rcu_read_unlock();
}
+#define TRACE_MMAP_LOCK_EVENT(type, mm, ...) \
+ do { \
+ const char *memcg_path; \
+ preempt_disable(); \
+ memcg_path = get_mm_memcg_path(mm); \
+ trace_mmap_lock_##type(mm, \
+ memcg_path != NULL ? memcg_path : "", \
+ ##__VA_ARGS__); \
+ if (likely(memcg_path != NULL)) \
+ put_memcg_path_buf(); \
+ preempt_enable(); \
+ } while (0)
+
+#else /* !CONFIG_MEMCG */
+
+int trace_mmap_lock_reg(void)
+{
+ return 0;
+}
+
+void trace_mmap_lock_unreg(void)
+{
+}
+
+#define TRACE_MMAP_LOCK_EVENT(type, mm, ...) \
+ trace_mmap_lock_##type(mm, "", ##__VA_ARGS__)
+
+#endif /* CONFIG_MEMCG */
+
+#ifdef CONFIG_TRACING
+#ifdef CONFIG_MEMCG
/*
* Write the given mm_struct's memcg path to a percpu buffer, and return a
* pointer to it. If the path cannot be determined, or no buffer was available
return buf;
}
-#define TRACE_MMAP_LOCK_EVENT(type, mm, ...) \
- do { \
- const char *memcg_path; \
- preempt_disable(); \
- memcg_path = get_mm_memcg_path(mm); \
- trace_mmap_lock_##type(mm, \
- memcg_path != NULL ? memcg_path : "", \
- ##__VA_ARGS__); \
- if (likely(memcg_path != NULL)) \
- put_memcg_path_buf(); \
- preempt_enable(); \
- } while (0)
-
-#else /* !CONFIG_MEMCG */
-
-int trace_mmap_lock_reg(void)
-{
- return 0;
-}
-
-void trace_mmap_lock_unreg(void)
-{
-}
-
-#define TRACE_MMAP_LOCK_EVENT(type, mm, ...) \
- trace_mmap_lock_##type(mm, "", ##__VA_ARGS__)
-
#endif /* CONFIG_MEMCG */
/*
TRACE_MMAP_LOCK_EVENT(released, mm, write);
}
EXPORT_SYMBOL(__mmap_lock_do_trace_released);
+#endif /* CONFIG_TRACING */