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<body class='hmmessage'><div dir='ltr'>is it possible that printk cause deadlock? the path is as below:<div><br><div>1. taskA runs on CPU0, and run schedule to acqire the rq->lock.</div><div>2. taskA calls printk while holding rq->lock.</div><div>3. taskA holds <span style="font-size: 12pt; ">console_sem.</span></div><div>4. taskB runs on CPU1, and call console_lock(), which is blocked by <span style="font-size: 12pt; ">console_sem and queue itslef to the wait list.</span></div><div><span style="font-size: 12pt; ">5. taskB migrates from CPU1 to cpu0. will this step occur?</span></div><div>6. taskA calls up(&console_sem)--> wake_up_process()-->try_to_wake_up()-->ttwu_queue()-->raw_spin_lock(&rq->lock). here taskA tries to acquire the rq->lock of CPU0 again. </div><div><br></div><div><br></div></div> </div></body>
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