[RFC][PATCH 2/7] wait: Provide

From: Peter Zijlstra
Date: Mon Aug 04 2014 - 06:42:10 EST


Add more might_sleep() checks, suppose someone put a wait_event() like
thing in a wait loop..

Can't put might_sleep() in ___wait_event() because there's the locked
primitives which call ___wait_event() with locks held.

Signed-off-by: Peter Zijlstra <peterz@xxxxxxxxxxxxx>
---
include/linux/wait.h | 16 ++++++++++++++++
1 file changed, 16 insertions(+)

--- a/include/linux/wait.h
+++ b/include/linux/wait.h
@@ -272,6 +272,7 @@ __out: __ret; \
*/
#define wait_event(wq, condition) \
do { \
+ might_sleep(); \
if (condition) \
break; \
__wait_event(wq, condition); \
@@ -302,6 +303,7 @@ do { \
#define wait_event_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
+ might_sleep(); \
if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_timeout(wq, condition, timeout); \
__ret; \
@@ -327,6 +329,7 @@ do { \
*/
#define wait_event_cmd(wq, condition, cmd1, cmd2) \
do { \
+ might_sleep(); \
if (condition) \
break; \
__wait_event_cmd(wq, condition, cmd1, cmd2); \
@@ -354,6 +357,7 @@ do { \
#define wait_event_interruptible(wq, condition) \
({ \
int __ret = 0; \
+ might_sleep(); \
if (!(condition)) \
__ret = __wait_event_interruptible(wq, condition); \
__ret; \
@@ -385,6 +389,7 @@ do { \
#define wait_event_interruptible_timeout(wq, condition, timeout) \
({ \
long __ret = timeout; \
+ might_sleep(); \
if (!___wait_cond_timeout(condition)) \
__ret = __wait_event_interruptible_timeout(wq, \
condition, timeout); \
@@ -435,6 +440,7 @@ do { \
#define wait_event_hrtimeout(wq, condition, timeout) \
({ \
int __ret = 0; \
+ might_sleep(); \
if (!(condition)) \
__ret = __wait_event_hrtimeout(wq, condition, timeout, \
TASK_UNINTERRUPTIBLE); \
@@ -460,6 +466,7 @@ do { \
#define wait_event_interruptible_hrtimeout(wq, condition, timeout) \
({ \
long __ret = 0; \
+ might_sleep(); \
if (!(condition)) \
__ret = __wait_event_hrtimeout(wq, condition, timeout, \
TASK_INTERRUPTIBLE); \
@@ -473,6 +480,7 @@ do { \
#define wait_event_interruptible_exclusive(wq, condition) \
({ \
int __ret = 0; \
+ might_sleep(); \
if (!(condition)) \
__ret = __wait_event_interruptible_exclusive(wq, condition);\
__ret; \
@@ -647,6 +655,7 @@ do { \
#define wait_event_killable(wq, condition) \
({ \
int __ret = 0; \
+ might_sleep(); \
if (!(condition)) \
__ret = __wait_event_killable(wq, condition); \
__ret; \
@@ -895,6 +904,7 @@ extern int bit_wait_io(struct wait_bit_k
static inline int
wait_on_bit(void *word, int bit, unsigned mode)
{
+ might_sleep();
if (!test_bit(bit, word))
return 0;
return out_of_line_wait_on_bit(word, bit,
@@ -919,6 +929,7 @@ wait_on_bit(void *word, int bit, unsigne
static inline int
wait_on_bit_io(void *word, int bit, unsigned mode)
{
+ might_sleep();
if (!test_bit(bit, word))
return 0;
return out_of_line_wait_on_bit(word, bit,
@@ -945,6 +956,7 @@ wait_on_bit_io(void *word, int bit, unsi
static inline int
wait_on_bit_action(void *word, int bit, wait_bit_action_f *action, unsigned mode)
{
+ might_sleep();
if (!test_bit(bit, word))
return 0;
return out_of_line_wait_on_bit(word, bit, action, mode);
@@ -972,6 +984,7 @@ wait_on_bit_action(void *word, int bit,
static inline int
wait_on_bit_lock(void *word, int bit, unsigned mode)
{
+ might_sleep();
if (!test_and_set_bit(bit, word))
return 0;
return out_of_line_wait_on_bit_lock(word, bit, bit_wait, mode);
@@ -995,6 +1008,7 @@ wait_on_bit_lock(void *word, int bit, un
static inline int
wait_on_bit_lock_io(void *word, int bit, unsigned mode)
{
+ might_sleep();
if (!test_and_set_bit(bit, word))
return 0;
return out_of_line_wait_on_bit_lock(word, bit, bit_wait_io, mode);
@@ -1020,6 +1034,7 @@ wait_on_bit_lock_io(void *word, int bit,
static inline int
wait_on_bit_lock_action(void *word, int bit, wait_bit_action_f *action, unsigned mode)
{
+ might_sleep();
if (!test_and_set_bit(bit, word))
return 0;
return out_of_line_wait_on_bit_lock(word, bit, action, mode);
@@ -1038,6 +1053,7 @@ wait_on_bit_lock_action(void *word, int
static inline
int wait_on_atomic_t(atomic_t *val, int (*action)(atomic_t *), unsigned mode)
{
+ might_sleep();
if (atomic_read(val) == 0)
return 0;
return out_of_line_wait_on_atomic_t(val, action, mode);


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