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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2015-12-13 17:57:10 +0100
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2016-02-24 04:59:52 +0100
commit23a9bacd357ab8388c7e07101b186a4282874992 (patch)
tree4764d724950b9f227699311cf66304f55cfa36a6 /kernel/rcu
parentrcu: Stop treating in-kernel CPU-bound workloads as errors (diff)
downloadlinux-23a9bacd357ab8388c7e07101b186a4282874992.tar.xz
linux-23a9bacd357ab8388c7e07101b186a4282874992.zip
rcu: Set rdp->gpwrap when CPU is idle
Commit #e3663b1024d1 ("rcu: Handle gpnum/completed wrap while dyntick idle") sets rdp->gpwrap on the wrong side of the "if" statement in dyntick_save_progress_counter(), that is, it sets it when the CPU is not idle instead of when it is idle. Of course, if the CPU is not idle, its rdp->gpnum won't be lagging beind the global rsp->gpnum, which means that rdp->gpwrap will never be set. This commit therefore moves this code to the proper leg of that "if" statement. This change means that the "else" cause is just "return 0" and the "then" clause ends with "return 1", so also move the "return 0" to follow the "if", dropping the "else" clause. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu')
-rw-r--r--kernel/rcu/tree.c5
1 files changed, 2 insertions, 3 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
index 68f4bee3ecc3..976a166f3fa3 100644
--- a/kernel/rcu/tree.c
+++ b/kernel/rcu/tree.c
@@ -1083,13 +1083,12 @@ static int dyntick_save_progress_counter(struct rcu_data *rdp,
rcu_sysidle_check_cpu(rdp, isidle, maxj);
if ((rdp->dynticks_snap & 0x1) == 0) {
trace_rcu_fqs(rdp->rsp->name, rdp->gpnum, rdp->cpu, TPS("dti"));
- return 1;
- } else {
if (ULONG_CMP_LT(READ_ONCE(rdp->gpnum) + ULONG_MAX / 4,
rdp->mynode->gpnum))
WRITE_ONCE(rdp->gpwrap, true);
- return 0;
+ return 1;
}
+ return 0;
}
/*