From: Zizhi Wo wozizhi@huawei.com
Offering: HULK hulk inclusion category: other bugzilla: https://gitee.com/openeuler/kernel/issues/IB5UKT
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For the previously combined 8238b4579866 ("wait_on_bit: add an acquire memory barrier") mainline patch, in order to avoid additional effects, revert the test_bit_acquire() in the wait_on_bit_xx function to the original test_bit().
In addition, define wait_on_bit_acquire() to narrow down the scope, which contains test_bit_acquire() that provide memory barrier.
Signed-off-by: Zizhi Wo wozizhi@huawei.com Signed-off-by: Baokun Li libaokun1@huawei.com --- include/linux/wait_bit.h | 33 +++++++++++++++++++++++++++---- kernel/sched/wait_bit.c | 42 +++++++++++++++++++++++++++++++++++++++- 2 files changed, 70 insertions(+), 5 deletions(-)
diff --git a/include/linux/wait_bit.h b/include/linux/wait_bit.h index 7725b7579b78..d31d256ce885 100644 --- a/include/linux/wait_bit.h +++ b/include/linux/wait_bit.h @@ -28,7 +28,9 @@ int __wait_on_bit(struct wait_queue_head *wq_head, struct wait_bit_queue_entry * int __wait_on_bit_lock(struct wait_queue_head *wq_head, struct wait_bit_queue_entry *wbq_entry, wait_bit_action_f *action, unsigned int mode); void wake_up_bit(void *word, int bit); int out_of_line_wait_on_bit(void *word, int, wait_bit_action_f *action, unsigned int mode); +int out_of_line_wait_on_bit_acquire(void *word, int, wait_bit_action_f *action, unsigned int mode); int out_of_line_wait_on_bit_timeout(void *word, int, wait_bit_action_f *action, unsigned int mode, unsigned long timeout); +int out_of_line_wait_on_bit_timeout_acquire(void *word, int, wait_bit_action_f *action, unsigned int mode, unsigned long timeout); int out_of_line_wait_on_bit_lock(void *word, int, wait_bit_action_f *action, unsigned int mode); struct wait_queue_head *bit_waitqueue(void *word, int bit); extern void __init wait_bit_init(void); @@ -71,7 +73,7 @@ static inline int wait_on_bit(unsigned long *word, int bit, unsigned mode) { might_sleep(); - if (!test_bit_acquire(bit, word)) + if (!test_bit(bit, word)) return 0; return out_of_line_wait_on_bit(word, bit, bit_wait, @@ -96,7 +98,7 @@ static inline int wait_on_bit_io(unsigned long *word, int bit, unsigned mode) { might_sleep(); - if (!test_bit_acquire(bit, word)) + if (!test_bit(bit, word)) return 0; return out_of_line_wait_on_bit(word, bit, bit_wait_io, @@ -123,7 +125,7 @@ wait_on_bit_timeout(unsigned long *word, int bit, unsigned mode, unsigned long timeout) { might_sleep(); - if (!test_bit_acquire(bit, word)) + if (!test_bit(bit, word)) return 0; return out_of_line_wait_on_bit_timeout(word, bit, bit_wait_timeout, @@ -151,7 +153,7 @@ wait_on_bit_action(unsigned long *word, int bit, wait_bit_action_f *action, unsigned mode) { might_sleep(); - if (!test_bit_acquire(bit, word)) + if (!test_bit(bit, word)) return 0; return out_of_line_wait_on_bit(word, bit, action, mode); } @@ -235,6 +237,29 @@ wait_on_bit_lock_action(unsigned long *word, int bit, wait_bit_action_f *action, return out_of_line_wait_on_bit_lock(word, bit, action, mode); }
+static inline int +wait_on_bit_acquire(unsigned long *word, int bit, unsigned mode) +{ + might_sleep(); + if (!test_bit_acquire(bit, word)) + return 0; + return out_of_line_wait_on_bit_acquire(word, bit, + bit_wait, + mode); +} + +static inline int +wait_on_bit_timeout_acquire(unsigned long *word, int bit, unsigned mode, + unsigned long timeout) +{ + might_sleep(); + if (!test_bit_acquire(bit, word)) + return 0; + return out_of_line_wait_on_bit_timeout_acquire(word, bit, + bit_wait_timeout, + mode, timeout); +} + extern void init_wait_var_entry(struct wait_bit_queue_entry *wbq_entry, void *var, int flags); extern void wake_up_var(void *var); extern wait_queue_head_t *__var_waitqueue(void *p); diff --git a/kernel/sched/wait_bit.c b/kernel/sched/wait_bit.c index 99be72732ee0..b795085b0b84 100644 --- a/kernel/sched/wait_bit.c +++ b/kernel/sched/wait_bit.c @@ -47,7 +47,7 @@ __wait_on_bit(struct wait_queue_head *wq_head, struct wait_bit_queue_entry *wbq_ prepare_to_wait(wq_head, &wbq_entry->wq_entry, mode); if (test_bit(wbq_entry->key.bit_nr, wbq_entry->key.flags)) ret = (*action)(&wbq_entry->key, mode); - } while (test_bit_acquire(wbq_entry->key.bit_nr, wbq_entry->key.flags) && !ret); + } while (test_bit(wbq_entry->key.bit_nr, wbq_entry->key.flags) && !ret);
finish_wait(wq_head, &wbq_entry->wq_entry);
@@ -55,6 +55,23 @@ __wait_on_bit(struct wait_queue_head *wq_head, struct wait_bit_queue_entry *wbq_ } EXPORT_SYMBOL(__wait_on_bit);
+static int __sched +__wait_on_bit_acquire(struct wait_queue_head *wq_head, struct wait_bit_queue_entry *wbq_entry, + wait_bit_action_f *action, unsigned mode) +{ + int ret = 0; + + do { + prepare_to_wait(wq_head, &wbq_entry->wq_entry, mode); + if (test_bit(wbq_entry->key.bit_nr, wbq_entry->key.flags)) + ret = (*action)(&wbq_entry->key, mode); + } while (test_bit_acquire(wbq_entry->key.bit_nr, wbq_entry->key.flags) && !ret); + + finish_wait(wq_head, &wbq_entry->wq_entry); + + return ret; +} + int __sched out_of_line_wait_on_bit(void *word, int bit, wait_bit_action_f *action, unsigned mode) { @@ -65,6 +82,29 @@ int __sched out_of_line_wait_on_bit(void *word, int bit, } EXPORT_SYMBOL(out_of_line_wait_on_bit);
+int __sched out_of_line_wait_on_bit_acquire(void *word, int bit, + wait_bit_action_f *action, unsigned mode) +{ + struct wait_queue_head *wq_head = bit_waitqueue(word, bit); + DEFINE_WAIT_BIT(wq_entry, word, bit); + + return __wait_on_bit_acquire(wq_head, &wq_entry, action, mode); +} +EXPORT_SYMBOL(out_of_line_wait_on_bit_acquire); + +int __sched out_of_line_wait_on_bit_timeout_acquire( + void *word, int bit, wait_bit_action_f *action, + unsigned mode, unsigned long timeout) +{ + struct wait_queue_head *wq_head = bit_waitqueue(word, bit); + DEFINE_WAIT_BIT(wq_entry, word, bit); + + wq_entry.key.timeout = jiffies + timeout; + + return __wait_on_bit_acquire(wq_head, &wq_entry, action, mode); +} +EXPORT_SYMBOL_GPL(out_of_line_wait_on_bit_timeout_acquire); + int __sched out_of_line_wait_on_bit_timeout( void *word, int bit, wait_bit_action_f *action, unsigned mode, unsigned long timeout)