Messages in this thread | | | Date | Thu, 6 Mar 2014 18:45:31 +0100 | From | Jiri Bohac <> | Subject | is printk() safe within a timekeeper_seq write section? |
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Hi,
I'm looking at the printk call in __timekeeping_inject_sleeptime(), introduced in cb5de2f8 (time: Catch invalid timespec sleep values in __timekeeping_inject_sleeptime)
Is it safe to call printk() while timekeeper_seq is held for writing?
What about this call chain? printk vprintk_emit console_unlock up(&console_sem) __up wake_up_process try_to_wake_up ttwu_do_activate ttwu_activate activate_task enqueue_task enqueue_task_fair hrtick_update hrtick_start_fair hrtick_start_fair get_time ktime_get --> endless loop on read_seqcount_retry(&timekeeper_seq, ...)
It looks like an unlikely but possible deadlock. Or did I overlook something?
Thanks!
-- Jiri Bohac <jbohac@suse.cz> SUSE Labs, SUSE CZ
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