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rcu: Add nocb_cb_kthread check to rcu_is_callbacks_kthread()

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Callbacks are invoked in RCU kthreads when calbacks are offloaded
(rcu_nocbs boot parameter) or when RCU's softirq handler has been
offloaded to rcuc kthreads (use_softirq==0).  The current code allows
for the rcu_nocbs case but not the use_softirq case.  This commit adds
support for the use_softirq case.

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Zqiang <qiang1.zhang@intel.com>
Signed-off-by: Paul E. McKenney <paulmck@kernel.org>
Reviewed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com>
This commit is contained in:
Zqiang 2022-04-29 20:42:22 +08:00 committed by Paul E. McKenney
parent b37a667c62
commit 5103850654
3 changed files with 22 additions and 17 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

4
kernel/rcu/tree.c
View File

@ -2530,7 +2530,7 @@ static void rcu_do_batch(struct rcu_data *rdp)
trace_rcu_batch_end(rcu_state.name, 0,
!rcu_segcblist_empty(&rdp->cblist),
need_resched(), is_idle_task(current),
rcu_is_callbacks_kthread());
rcu_is_callbacks_kthread(rdp));
return;
}
@ -2608,7 +2608,7 @@ static void rcu_do_batch(struct rcu_data *rdp)
rcu_nocb_lock_irqsave(rdp, flags);
rdp->n_cbs_invoked += count;
trace_rcu_batch_end(rcu_state.name, count, !!rcl.head, need_resched(),
is_idle_task(current), rcu_is_callbacks_kthread());
is_idle_task(current), rcu_is_callbacks_kthread(rdp));
/* Update counts and requeue any remaining callbacks. */
rcu_segcblist_insert_done_cbs(&rdp->cblist, &rcl);

2
kernel/rcu/tree.h
View File

@ -426,7 +426,7 @@ static void rcu_flavor_sched_clock_irq(int user);
static void dump_blkd_tasks(struct rcu_node *rnp, int ncheck);
static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags);
static void rcu_preempt_boost_start_gp(struct rcu_node *rnp);
static bool rcu_is_callbacks_kthread(void);
static bool rcu_is_callbacks_kthread(struct rcu_data *rdp);
static void rcu_cpu_kthread_setup(unsigned int cpu);
static void rcu_spawn_one_boost_kthread(struct rcu_node *rnp);
static bool rcu_preempt_has_tasks(struct rcu_node *rnp);

33
kernel/rcu/tree_plugin.h
View File

@ -1012,6 +1012,25 @@ static void rcu_cpu_kthread_setup(unsigned int cpu)
WRITE_ONCE(rdp->rcuc_activity, jiffies);
}
static bool rcu_is_callbacks_nocb_kthread(struct rcu_data *rdp)
{
#ifdef CONFIG_RCU_NOCB_CPU
return rdp->nocb_cb_kthread == current;
#else
return false;
#endif
}
/*
* Is the current CPU running the RCU-callbacks kthread?
* Caller must have preemption disabled.
*/
static bool rcu_is_callbacks_kthread(struct rcu_data *rdp)
{
return rdp->rcu_cpu_kthread_task == current ||
rcu_is_callbacks_nocb_kthread(rdp);
}
#ifdef CONFIG_RCU_BOOST
/*
@ -1151,15 +1170,6 @@ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags)
}
}
/*
* Is the current CPU running the RCU-callbacks kthread?
* Caller must have preemption disabled.
*/
static bool rcu_is_callbacks_kthread(void)
{
return __this_cpu_read(rcu_data.rcu_cpu_kthread_task) == current;
}
#define RCU_BOOST_DELAY_JIFFIES DIV_ROUND_UP(CONFIG_RCU_BOOST_DELAY * HZ, 1000)
/*
@ -1242,11 +1252,6 @@ static void rcu_initiate_boost(struct rcu_node *rnp, unsigned long flags)
raw_spin_unlock_irqrestore_rcu_node(rnp, flags);
}
static bool rcu_is_callbacks_kthread(void)
{
return false;
}
static void rcu_preempt_boost_start_gp(struct rcu_node *rnp)
{
}