From: Paul E. McKenney Date: Thu, 12 Jan 2012 01:25:17 +0000 (-0800) Subject: rcu: Simplify unboosting checks X-Git-Tag: v3.4-rc1~194^2^2~26 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=1aa03f1188f7b0b85df2de602b33ee7b6fab8e00;p=pandora-kernel.git rcu: Simplify unboosting checks This is a port of commit #82e78d80 from TREE_PREEMPT_RCU to TINY_PREEMPT_RCU. This commit uses the fact that current->rcu_boost_mutex is set any time that the RCU_READ_UNLOCK_BOOSTED flag is set in the current->rcu_read_unlock_special bitmask. This allows tests of the bit to be changed to tests of the pointer, which in turn allows the RCU_READ_UNLOCK_BOOSTED flag to be eliminated. Please note that the check of current->rcu_read_unlock_special need not change because any time that RCU_READ_UNLOCK_BOOSTED was set, so was RCU_READ_UNLOCK_BLOCKED. Therefore, __rcu_read_unlock() can continue testing current->rcu_read_unlock_special for non-zero, as before. Signed-off-by: Paul E. McKenney Signed-off-by: Paul E. McKenney --- Reading git-diff-tree failed