This is a note to let you know that I've just added the patch titled

rcu: Fix up pending cbs check in rcu_prepare_for_idle

to the 4.13-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...

The filename of the patch is: rcu-fix-up-pending-cbs-check-in-rcu_prepare_for_idle.patch and it can be found in the queue-4.13 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.

From 135bd1a230bb69a68c9808a7d25467318900b80a Mon Sep 17 00:00:00 2001

From: Neeraj Upadhyay neeraju@codeaurora.org Date: Mon, 7 Aug 2017 11:20:10 +0530 Subject: rcu: Fix up pending cbs check in rcu_prepare_for_idle

From: Neeraj Upadhyay neeraju@codeaurora.org

commit 135bd1a230bb69a68c9808a7d25467318900b80a upstream.

The pending-callbacks check in rcu_prepare_for_idle() is backwards. It should accelerate if there are pending callbacks, but the check rather uselessly accelerates only if there are no callbacks. This commit therefore inverts this check.

Fixes: 15fecf89e46a ("srcu: Abstract multi-tail callback list handling") Signed-off-by: Neeraj Upadhyay neeraju@codeaurora.org Signed-off-by: Paul E. McKenney paulmck@linux.vnet.ibm.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org

--- kernel/rcu/tree_plugin.h | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/kernel/rcu/tree_plugin.h +++ b/kernel/rcu/tree_plugin.h @@ -1493,7 +1493,7 @@ static void rcu_prepare_for_idle(void) rdtp->last_accelerate = jiffies; for_each_rcu_flavor(rsp) { rdp = this_cpu_ptr(rsp->rda); - if (rcu_segcblist_pend_cbs(&rdp->cblist)) + if (!rcu_segcblist_pend_cbs(&rdp->cblist)) continue; rnp = rdp->mynode; raw_spin_lock_rcu_node(rnp); /* irqs already disabled. */

Patches currently in stable-queue which might be from neeraju@codeaurora.org are

queue-4.13/rcu-fix-up-pending-cbs-check-in-rcu_prepare_for_idle.patch