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| author | Joel Fernandes (Google) <joel@joelfernandes.org> | 2018-05-13 20:15:41 -0700 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.vnet.ibm.com> | 2018-07-12 15:38:53 -0700 |
| commit | 5ca0905f6787e930bc2a626cf1d8f69fab52acef (patch) | |
| tree | 5bcacd1ddb00b2596b86905b4f2b764ae0a7d8db /kernel/rcu | |
| parent | 5b55072f22ba2ed136b7a1b6c5beea9ace8415a7 (diff) | |
| download | linux-stable-5ca0905f6787e930bc2a626cf1d8f69fab52acef.tar.gz linux-stable-5ca0905f6787e930bc2a626cf1d8f69fab52acef.tar.bz2 linux-stable-5ca0905f6787e930bc2a626cf1d8f69fab52acef.zip | |
rcu: Fix cpustart tracepoint gp_seq number
The "cpustart" trace event shows a stale gp_seq. This is because it uses
rdp->gp_seq, which is updated only at the end of the __note_gp_changes()
function. This commit therefore instead uses rnp->gp_seq.
An alternative fix would be to update rdp->gp_seq earlier, but this would
break RCU's detection of the beginning of a new-to-this-CPU grace period.
Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org>
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu')
| -rw-r--r-- | kernel/rcu/tree.c | 2 |
1 files changed, 1 insertions, 1 deletions
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 73a33b82cfcd..973250503d98 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -1801,7 +1801,7 @@ static bool __note_gp_changes(struct rcu_state *rsp, struct rcu_node *rnp, * set up to detect a quiescent state, otherwise don't * go looking for one. */ - trace_rcu_grace_period(rsp->name, rdp->gp_seq, TPS("cpustart")); + trace_rcu_grace_period(rsp->name, rnp->gp_seq, TPS("cpustart")); need_gp = !!(rnp->qsmask & rdp->grpmask); rdp->cpu_no_qs.b.norm = need_gp; rdp->rcu_qs_ctr_snap = __this_cpu_read(rcu_dynticks.rcu_qs_ctr); |