Re: [PATCH 0/6] sched, wait: Collapse __wait_event macros -v4

From: Oleg Nesterov
Date: Mon Sep 30 2013 - 13:47:59 EST


On 09/30, Peter Zijlstra wrote:
>
> Compile and boot tested on x86_64.

Looks fine, but I'll try to actually read this series tomorrow.
Not that I think this needs my review ;)

But at first glance, I think that something like below makes sense
as 7/6.

Once again, of course I do not blame this series, but
wait_event_timeout(wq, true, 0) still returns 0.

Oleg.


--- x/include/linux/wait.h
+++ x/include/linux/wait.h
@@ -184,9 +184,14 @@ wait_queue_head_t *bit_waitqueue(void *,
bool __cond = (condition); \
if (__cond && !__ret) \
__ret = 1; \
- __cond || !__ret; \
+ __cond; \
})

+#define ___wait_schedule_timeout(tout) \
+ if (!tout) \
+ break; \
+ tout = schedule_timeout(tout)
+
#define ___wait_signal_pending(state) \
((state == TASK_INTERRUPTIBLE && signal_pending(current)) || \
(state == TASK_KILLABLE && fatal_signal_pending(current)))
@@ -248,7 +253,7 @@ do { \
#define __wait_event_timeout(wq, condition, timeout) \
___wait_event(wq, ___wait_cond_timeout(condition), \
TASK_UNINTERRUPTIBLE, 0, timeout, \
- __ret = schedule_timeout(__ret))
+ ___wait_schedule_timeout(__ret))

/**
* wait_event_timeout - sleep until a condition gets true or a timeout elapses
@@ -270,7 +275,7 @@ do { \
#define wait_event_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
- if (!(condition)) \
+ if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_timeout(wq, condition, timeout); \
__ret; \
})
@@ -305,7 +310,7 @@ do { \
#define __wait_event_interruptible_timeout(wq, condition, timeout) \
___wait_event(wq, ___wait_cond_timeout(condition), \
TASK_INTERRUPTIBLE, 0, timeout, \
- __ret = schedule_timeout(__ret))
+ ___wait_schedule_timeout(__ret))

/**
* wait_event_interruptible_timeout - sleep until a condition gets true or a timeout elapses
@@ -328,7 +333,7 @@ do { \
#define wait_event_interruptible_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
- if (!(condition)) \
+ if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_interruptible_timeout(wq, \
condition, timeout); \
__ret; \
@@ -739,7 +744,7 @@ do { \
___wait_event(wq, ___wait_cond_timeout(condition), \
TASK_INTERRUPTIBLE, 0, ret, \
spin_unlock_irq(&lock); \
- __ret = schedule_timeout(__ret); \
+ ___wait_schedule_timeout(__ret); \
spin_lock_irq(&lock));

/**
@@ -770,7 +775,7 @@ do { \
timeout) \
({ \
long __ret = timeout; \
- if (!(condition)) \
+ if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_interruptible_lock_irq_timeout( \
wq, condition, lock, timeout); \
__ret; \

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