sched: Add get_current_state()

Remove yet another few p->state accesses.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210611082838.347475156@infradead.org

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 655db5fb46d01e9c6f790151e2a67d212db86f89..56270bb06365ec9c90d1cc9fb9a0afd894c184b2 100644 (file)
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -3910,7 +3910,7 @@ int blk_poll(struct request_queue *q, blk_qc_t cookie, bool spin)
 
        hctx->poll_considered++;
 
-       state = current->state;
+       state = get_current_state();
        do {
                int ret;
 

diff --git a/include/linux/sched.h b/include/linux/sched.h
index 2cd56352dae14a1768dff4be265e04b589c2fd38..395c8906f502db36a1c53e3923808be3e1256c5a 100644 (file)
--- a/include/linux/sched.h
+++ b/include/linux/sched.h
@@ -213,6 +213,8 @@ struct task_group;
 
 #endif
 
+#define get_current_state()    READ_ONCE(current->state)
+
 /* Task command name length: */
 #define TASK_COMM_LEN                  16
 

diff --git a/kernel/freezer.c b/kernel/freezer.c
index dc520f01f99ddc053366ab5fdbaffd126f519c24..45ab36ffd0e79cf84fe4a47323811e27ae11357d 100644 (file)
--- a/kernel/freezer.c
+++ b/kernel/freezer.c
@@ -58,7 +58,7 @@ bool __refrigerator(bool check_kthr_stop)
        /* Hmm, should we be allowed to suspend when there are realtime
           processes around? */
        bool was_frozen = false;
-       long save = current->state;
+       unsigned int save = get_current_state();
 
        pr_debug("%s entered refrigerator\n", current->comm);
 

diff --git a/kernel/sched/core.c b/kernel/sched/core.c
index 618c2b5a5758f38585942b24e5f456f07aef7889..45ebb3cfe86ca3af9dcd41752573c6e6ac5016df 100644 (file)
--- a/kernel/sched/core.c
+++ b/kernel/sched/core.c
@@ -9098,15 +9098,15 @@ static inline int preempt_count_equals(int preempt_offset)
 
 void __might_sleep(const char *file, int line, int preempt_offset)
 {
+       unsigned int state = get_current_state();
        /*
         * Blocking primitives will set (and therefore destroy) current->state,
         * since we will exit with TASK_RUNNING make sure we enter with it,
         * otherwise we will destroy state.
         */
-       WARN_ONCE(current->state != TASK_RUNNING && current->task_state_change,
+       WARN_ONCE(state != TASK_RUNNING && current->task_state_change,
                        "do not call blocking ops when !TASK_RUNNING; "
-                       "state=%lx set at [<%p>] %pS\n",
-                       current->state,
+                       "state=%x set at [<%p>] %pS\n", state,
                        (void *)current->task_state_change,
                        (void *)current->task_state_change);