From: "Paul E. McKenney" <[email protected]> The current implementation of cond_resched_rcu_qs() can invoke rcu_note_voluntary_context_switch() twice in the should_resched() case, once via the call to __schedule() and once directly. However, as noted by Joe Lawrence in a patch to the team subsystem, cond_resched() returns an indication as to whether or not the call to __schedule() actually happened. This commit therefore changes cond_resched_rcu_qs() so as to invoke rcu_note_voluntary_context_switch() only when __schedule() was not called.
Signed-off-by: Paul E. McKenney <[email protected]> --- include/linux/rcupdate.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/include/linux/rcupdate.h b/include/linux/rcupdate.h index a033d8b55773..36ea3ba5c516 100644 --- a/include/linux/rcupdate.h +++ b/include/linux/rcupdate.h @@ -348,8 +348,8 @@ extern struct srcu_struct tasks_rcu_exit_srcu; */ #define cond_resched_rcu_qs() \ do { \ - rcu_note_voluntary_context_switch(current); \ - cond_resched(); \ + if (!cond_resched()) \ + rcu_note_voluntary_context_switch(current); \ } while (0) #if defined(CONFIG_DEBUG_LOCK_ALLOC) || defined(CONFIG_RCU_TRACE) || defined(CONFIG_SMP) -- 1.8.1.5 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
