diff options
| author | Ingo Molnar <mingo@elte.hu> | 2009-07-03 08:30:12 -0500 |
|---|---|---|
| committer | Clark Williams <williams@redhat.com> | 2012-03-07 16:14:58 -0600 |
| commit | 8204b22698908a6d26adac4e9abf05096a576cd7 (patch) | |
| tree | d1fb3222a27f2677690f57e71b01b7f22c2f7f4a /ipc | |
| parent | 5382e5fc987365bee2588bfc70cc65b5e4c4c8ec (diff) | |
ipc: Make the ipc code -rt aware
RT serializes the code with the (rt)spinlock but keeps preemption
enabled. Some parts of the code need to be atomic nevertheless.
Protect it with preempt_disable/enable_rt pairts.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Diffstat (limited to 'ipc')
| -rw-r--r-- | ipc/mqueue.c | 5 | ||||
| -rw-r--r-- | ipc/msg.c | 16 |
2 files changed, 21 insertions, 0 deletions
diff --git a/ipc/mqueue.c b/ipc/mqueue.c index 5b4293d9819d..2d06b545bfdb 100644 --- a/ipc/mqueue.c +++ b/ipc/mqueue.c @@ -820,12 +820,17 @@ static inline void pipelined_send(struct mqueue_inode_info *info, struct msg_msg *message, struct ext_wait_queue *receiver) { + /* + * Keep them in one critical section for PREEMPT_RT: + */ + preempt_disable_rt(); receiver->msg = message; list_del(&receiver->list); receiver->state = STATE_PENDING; wake_up_process(receiver->task); smp_wmb(); receiver->state = STATE_READY; + preempt_enable_rt(); } /* pipelined_receive() - if there is task waiting in sys_mq_timedsend() diff --git a/ipc/msg.c b/ipc/msg.c index 7385de25788a..06642ac5bb8f 100644 --- a/ipc/msg.c +++ b/ipc/msg.c @@ -259,12 +259,20 @@ static void expunge_all(struct msg_queue *msq, int res) while (tmp != &msq->q_receivers) { struct msg_receiver *msr; + /* + * Make sure that the wakeup doesnt preempt + * this CPU prematurely. (on PREEMPT_RT) + */ + preempt_disable_rt(); + msr = list_entry(tmp, struct msg_receiver, r_list); tmp = tmp->next; msr->r_msg = NULL; wake_up_process(msr->r_tsk); smp_mb(); msr->r_msg = ERR_PTR(res); + + preempt_enable_rt(); } } @@ -611,6 +619,12 @@ static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg) !security_msg_queue_msgrcv(msq, msg, msr->r_tsk, msr->r_msgtype, msr->r_mode)) { + /* + * Make sure that the wakeup doesnt preempt + * this CPU prematurely. (on PREEMPT_RT) + */ + preempt_disable_rt(); + list_del(&msr->r_list); if (msr->r_maxsize < msg->m_ts) { msr->r_msg = NULL; @@ -624,9 +638,11 @@ static inline int pipelined_send(struct msg_queue *msq, struct msg_msg *msg) wake_up_process(msr->r_tsk); smp_mb(); msr->r_msg = msg; + preempt_enable_rt(); return 1; } + preempt_enable_rt(); } } return 0; |