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| author | Paul E. McKenney <paulmck@kernel.org> | 2022-02-23 17:29:37 -0800 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@kernel.org> | 2022-04-11 17:28:48 -0700 |
| commit | c708b08c65a0dfae127b9ee33b0fb73535a5e066 (patch) | |
| tree | 3dc0ab8b7a448ab78d1c27fb11933e757e6dbc56 /kernel/rcu/tree.h | |
| parent | 90d2efe7bdbde5371b6122174af0718843f805c6 (diff) | |
| download | linux-stable-c708b08c65a0dfae127b9ee33b0fb73535a5e066.tar.gz linux-stable-c708b08c65a0dfae127b9ee33b0fb73535a5e066.tar.bz2 linux-stable-c708b08c65a0dfae127b9ee33b0fb73535a5e066.zip | |
rcu: Check for jiffies going backwards
A report of a 12-jiffy normal RCU CPU stall warning raises interesting
questions about the nature of time on the offending system. This commit
instruments rcu_sched_clock_irq(), which is RCU's hook into the
scheduling-clock interrupt, checking for the jiffies counter going
backwards.
Reported-by: Saravanan D <sarvanand@fb.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Diffstat (limited to 'kernel/rcu/tree.h')
| -rw-r--r-- | kernel/rcu/tree.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/kernel/rcu/tree.h b/kernel/rcu/tree.h index 926673ebe355..94b55f669915 100644 --- a/kernel/rcu/tree.h +++ b/kernel/rcu/tree.h @@ -254,6 +254,7 @@ struct rcu_data { unsigned long rcu_onl_gp_seq; /* ->gp_seq at last online. */ short rcu_onl_gp_flags; /* ->gp_flags at last online. */ unsigned long last_fqs_resched; /* Time of last rcu_resched(). */ + unsigned long last_sched_clock; /* Jiffies of last rcu_sched_clock_irq(). */ int cpu; }; |