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authorPeter Zijlstra <peterz@infradead.org>2014-09-24 10:18:47 +0200
committerIngo Molnar <mingo@kernel.org>2014-10-28 10:55:15 +0100
commit61ada528dea028331e99e8ceaed87c683ad25de2 (patch)
tree0037fc75e3629576238dce932babf7738e80cb86 /include/linux/wait.h
parent6f942a1f264e875c5f3ad6f505d7b500a3e7fa82 (diff)
sched/wait: Provide infrastructure to deal with nested blocking
There are a few places that call blocking primitives from wait loops, provide infrastructure to support this without the typical task_struct::state collision. We record the wakeup in wait_queue_t::flags which leaves task_struct::state free to be used by others. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Reviewed-by: Oleg Nesterov <oleg@redhat.com> Cc: tglx@linutronix.de Cc: ilya.dryomov@inktank.com Cc: umgwanakikbuti@gmail.com Cc: Linus Torvalds <torvalds@linux-foundation.org> Link: http://lkml.kernel.org/r/20140924082242.051202318@infradead.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'include/linux/wait.h')
-rw-r--r--include/linux/wait.h7
1 files changed, 6 insertions, 1 deletions
diff --git a/include/linux/wait.h b/include/linux/wait.h
index e4a8eb9312e..fc0e99395fb 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -13,9 +13,12 @@ typedef struct __wait_queue wait_queue_t;
typedef int (*wait_queue_func_t)(wait_queue_t *wait, unsigned mode, int flags, void *key);
int default_wake_function(wait_queue_t *wait, unsigned mode, int flags, void *key);
+/* __wait_queue::flags */
+#define WQ_FLAG_EXCLUSIVE 0x01
+#define WQ_FLAG_WOKEN 0x02
+
struct __wait_queue {
unsigned int flags;
-#define WQ_FLAG_EXCLUSIVE 0x01
void *private;
wait_queue_func_t func;
struct list_head task_list;
@@ -830,6 +833,8 @@ void prepare_to_wait_exclusive(wait_queue_head_t *q, wait_queue_t *wait, int sta
long prepare_to_wait_event(wait_queue_head_t *q, wait_queue_t *wait, int state);
void finish_wait(wait_queue_head_t *q, wait_queue_t *wait);
void abort_exclusive_wait(wait_queue_head_t *q, wait_queue_t *wait, unsigned int mode, void *key);
+long wait_woken(wait_queue_t *wait, unsigned mode, long timeout);
+int woken_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
int autoremove_wake_function(wait_queue_t *wait, unsigned mode, int sync, void *key);
int wake_bit_function(wait_queue_t *wait, unsigned mode, int sync, void *key);