sched/wait: Introduce ___wait_event()

There's far too much duplication in the __wait_event macros; in order
to fix this introduce ___wait_event() a macro with the capability to
replace most other macros.

With the previous patches changing the various __wait_event*()
implementations to be more uniform; we can now collapse the lot
without also changing generated code.

Reviewed-by: Oleg Nesterov <oleg@redhat.com>
Signed-off-by: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20131002092528.181897111@infradead.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 36 insertions, 0 deletions

diff --git a/include/linux/wait.h b/include/linux/wait.h
index 7d7819dafcc5..29d0249e03ab 100644
--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -187,6 +187,42 @@ wait_queue_head_t *bit_waitqueue(void *, int);
         __cond || !ret;                                                 \
 })
 
+#define ___wait_signal_pending(state)                                   \
+        ((state == TASK_INTERRUPTIBLE && signal_pending(current)) ||    \
+         (state == TASK_KILLABLE && fatal_signal_pending(current)))
+
+#define ___wait_nop_ret         int ret __always_unused
+
+#define ___wait_event(wq, condition, state, exclusive, ret, cmd)        \
+do {                                                                    \
+        __label__ __out;                                                \
+        DEFINE_WAIT(__wait);                                            \
+                                                                        \
+        for (;;) {                                                      \
+                if (exclusive)                                          \
+                        prepare_to_wait_exclusive(&wq, &__wait, state); \
+                else                                                    \
+                        prepare_to_wait(&wq, &__wait, state);           \
+                                                                        \
+                if (condition)                                          \
+                        break;                                          \
+                                                                        \
+                if (___wait_signal_pending(state)) {                    \
+                        ret = -ERESTARTSYS;                             \
+                        if (exclusive) {                                \
+                                abort_exclusive_wait(&wq, &__wait,      \
+                                                     state, NULL);      \
+                                goto __out;                             \
+                        }                                               \
+                        break;                                          \
+                }                                                       \
+                                                                        \
+                cmd;                                                    \
+        }                                                               \
+        finish_wait(&wq, &__wait);                                      \
+__out:  ;                                                               \
+} while (0)
+
 #define __wait_event(wq, condition)                                     \
 do {                                                                    \
         DEFINE_WAIT(__wait);                                            \