Commit-ID: f123c98e7f168e949b283690693695f988332c3d Gitweb: http://git.kernel.org/tip/f123c98e7f168e949b283690693695f988332c3d Author: Steven Rostedt <srostedt@xxxxxxxxxx> AuthorDate: Thu, 6 Jan 2011 15:08:29 -0500 Committer: Ingo Molnar <mingo@xxxxxxx> CommitDate: Tue, 11 Jan 2011 15:17:24 +0100 rtmutex: Fix comment about why new_owner can be NULL in wake_futex_pi() The comment about why rt_mutex_next_owner() can return NULL in wake_futex_pi() is not the normal case. Tracing the cause of why this occurs is more likely that waiter simply timedout. But because it originally caused contention with the futex, the owner will go into the kernel when it unlocks the lock. Then it will hit this code path and rt_mutex_next_owner() will return NULL. Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx> Signed-off-by: Ingo Molnar <mingo@xxxxxxx> --- kernel/futex.c | 7 +++---- 1 files changed, 3 insertions(+), 4 deletions(-) diff --git a/kernel/futex.c b/kernel/futex.c index 3019b92..5696d38 100644 --- a/kernel/futex.c +++ b/kernel/futex.c @@ -791,10 +791,9 @@ static int wake_futex_pi(u32 __user *uaddr, u32 uval, struct futex_q *this) new_owner = rt_mutex_next_owner(&pi_state->pi_mutex); /* - * This happens when we have stolen the lock and the original - * pending owner did not enqueue itself back on the rt_mutex. - * Thats not a tragedy. We know that way, that a lock waiter - * is on the fly. We make the futex_q waiter the pending owner. + * It is possible that the next waiter (the one that brought + * this owner to the kernel) timed out and is no longer + * waiting on the lock. */ if (!new_owner) new_owner = this->task; -- To unsubscribe from this list: send the line "unsubscribe linux-tip-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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