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| author | Sebastian Andrzej Siewior <bigeasy@linutronix.de> | 2018-12-11 12:12:38 +0100 |
|---|---|---|
| committer | Paul E. McKenney <paulmck@linux.ibm.com> | 2019-01-25 15:36:42 -0800 |
| commit | e81baf4cb19a9b428ba477fd0423f81672a58817 (patch) | |
| tree | fd518df0bf3f31968c4541ff488f0c727cc1b2b2 /include/linux/srcutree.h | |
| parent | c8ca1aa774b20f182733d1661f3b6aa3105338e7 (diff) | |
| download | linux-stable-e81baf4cb19a9b428ba477fd0423f81672a58817.tar.gz linux-stable-e81baf4cb19a9b428ba477fd0423f81672a58817.tar.bz2 linux-stable-e81baf4cb19a9b428ba477fd0423f81672a58817.zip | |
srcu: Remove srcu_queue_delayed_work_on()
srcu_queue_delayed_work_on() disables preemption (and therefore CPU
hotplug in RCU's case) and then checks based on its own accounting if a
CPU is online. If the CPU is online it uses queue_delayed_work_on()
otherwise it fallbacks to queue_delayed_work().
The problem here is that queue_work() on -RT does not work with disabled
preemption.
queue_work_on() works also on an offlined CPU. queue_delayed_work_on()
has the problem that it is possible to program a timer on an offlined
CPU. This timer will fire once the CPU is online again. But until then,
the timer remains programmed and nothing will happen.
Add a local timer which will fire (as requested per delay) on the local
CPU and then enqueue the work on the specific CPU.
RCUtorture testing with SRCU-P for 24h showed no problems.
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Paul E. McKenney <paulmck@linux.ibm.com>
Diffstat (limited to 'include/linux/srcutree.h')
| -rw-r--r-- | include/linux/srcutree.h | 3 |
1 files changed, 2 insertions, 1 deletions
diff --git a/include/linux/srcutree.h b/include/linux/srcutree.h index 6f292bd3e7db..0faa978c9880 100644 --- a/include/linux/srcutree.h +++ b/include/linux/srcutree.h @@ -45,7 +45,8 @@ struct srcu_data { unsigned long srcu_gp_seq_needed; /* Furthest future GP needed. */ unsigned long srcu_gp_seq_needed_exp; /* Furthest future exp GP. */ bool srcu_cblist_invoking; /* Invoking these CBs? */ - struct delayed_work work; /* Context for CB invoking. */ + struct timer_list delay_work; /* Delay for CB invoking */ + struct work_struct work; /* Context for CB invoking. */ struct rcu_head srcu_barrier_head; /* For srcu_barrier() use. */ struct srcu_node *mynode; /* Leaf srcu_node. */ unsigned long grpmask; /* Mask for leaf srcu_node */ |