futex: Enhance comments in futex_lock_pi() for blocking paths (767f509c) · Commits · 戴 / test

... serves a bit better to clarify between blocking and non-blocking code paths. Signed-off-by:

Davidlohr Bueso <dbueso@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Darren Hart <darren@dvhart.com> Cc: Davidlohr Bueso <dave@stgolabs.net> Link: http://lkml.kernel.org/r/1435645562-975-2-git-send-email-dave@stgolabs.net Signed-off-by:

kernel/futex.c

+9 −2

Original line number	Diff line number	Diff line
		@@ -2268,8 +2268,11 @@ static long futex_wait_restart(struct restart_block *restart)
		/*
		* Userspace tried a 0 -> TID atomic transition of the futex value
		* and failed. The kernel side here does the whole locking operation:
		* if there are waiters then it will block, it does PI, etc. (Due to
		* races the kernel might see a 0 value of the futex too.)
		* if there are waiters then it will block as a consequence of relying
		* on rt-mutexes, it does PI, etc. (Due to races the kernel might see
		* a 0 value of the futex too.).
		*
		* Also serves as futex trylock_pi()'ing, and due semantics.
		*/
		static int futex_lock_pi(u32 __user *uaddr, unsigned int flags,
		ktime_t *time, int trylock)
		@@ -2300,6 +2303,10 @@ retry_private:

		ret = futex_lock_pi_atomic(uaddr, hb, &q.key, &q.pi_state, current, 0);
		if (unlikely(ret)) {
		/*
		* Atomic work succeeded and we got the lock,
		* or failed. Either way, we do _not_ block.
		*/
		switch (ret) {
		case 1:
		/* We got the lock. */