| Message ID | 20220620222032.3839547-9-paulmck@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | fd512d3618173c562fa61263e868be565905a7ee |
| Headers | show |
| Series | Miscellaneous fixes for v5.20 | expand |
On 6/21/2022 3:50 AM, Paul E. McKenney wrote: > From: "Joel Fernandes (Google)" <joel@joelfernandes.org> > > monitor_todo is not needed as the work struct already tracks > if work is pending. Just use that to know if work is pending > using schedule_delayed_work() helper. > > Signed-off-by: Joel Fernandes (Google) <joel@joelfernandes.org> > Signed-off-by: Uladzislau Rezki (Sony) <urezki@gmail.com> > Signed-off-by: Paul E. McKenney <paulmck@kernel.org> > --- Reviewed-by: Neeraj Upadhyay <quic_neeraju@quicinc.com> Thanks Neeraj > kernel/rcu/tree.c | 33 ++++++++++++++++----------------- > 1 file changed, 16 insertions(+), 17 deletions(-) > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index 5445b19b48408..7919d7b48fa6a 100644 > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -3216,7 +3216,6 @@ struct kfree_rcu_cpu_work { > * @krw_arr: Array of batches of kfree_rcu() objects waiting for a grace period > * @lock: Synchronize access to this structure > * @monitor_work: Promote @head to @head_free after KFREE_DRAIN_JIFFIES > - * @monitor_todo: Tracks whether a @monitor_work delayed work is pending > * @initialized: The @rcu_work fields have been initialized > * @count: Number of objects for which GP not started > * @bkvcache: > @@ -3241,7 +3240,6 @@ struct kfree_rcu_cpu { > struct kfree_rcu_cpu_work krw_arr[KFREE_N_BATCHES]; > raw_spinlock_t lock; > struct delayed_work monitor_work; > - bool monitor_todo; > bool initialized; > int count; > > @@ -3421,6 +3419,18 @@ static void kfree_rcu_work(struct work_struct *work) > } > } > > +static bool > +need_offload_krc(struct kfree_rcu_cpu *krcp) > +{ > + int i; > + > + for (i = 0; i < FREE_N_CHANNELS; i++) > + if (krcp->bkvhead[i]) > + return true; > + > + return !!krcp->head; > +} > + > /* > * This function is invoked after the KFREE_DRAIN_JIFFIES timeout. > */ > @@ -3477,9 +3487,7 @@ static void kfree_rcu_monitor(struct work_struct *work) > // of the channels that is still busy we should rearm the > // work to repeat an attempt. Because previous batches are > // still in progress. > - if (!krcp->bkvhead[0] && !krcp->bkvhead[1] && !krcp->head) > - krcp->monitor_todo = false; > - else > + if (need_offload_krc(krcp)) > schedule_delayed_work(&krcp->monitor_work, KFREE_DRAIN_JIFFIES); > > raw_spin_unlock_irqrestore(&krcp->lock, flags); > @@ -3667,11 +3675,8 @@ void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func) > WRITE_ONCE(krcp->count, krcp->count + 1); > > // Set timer to drain after KFREE_DRAIN_JIFFIES. > - if (rcu_scheduler_active == RCU_SCHEDULER_RUNNING && > - !krcp->monitor_todo) { > - krcp->monitor_todo = true; > + if (rcu_scheduler_active == RCU_SCHEDULER_RUNNING) > schedule_delayed_work(&krcp->monitor_work, KFREE_DRAIN_JIFFIES); > - } > > unlock_return: > krc_this_cpu_unlock(krcp, flags); > @@ -3746,14 +3751,8 @@ void __init kfree_rcu_scheduler_running(void) > struct kfree_rcu_cpu *krcp = per_cpu_ptr(&krc, cpu); > > raw_spin_lock_irqsave(&krcp->lock, flags); > - if ((!krcp->bkvhead[0] && !krcp->bkvhead[1] && !krcp->head) || > - krcp->monitor_todo) { > - raw_spin_unlock_irqrestore(&krcp->lock, flags); > - continue; > - } > - krcp->monitor_todo = true; > - schedule_delayed_work_on(cpu, &krcp->monitor_work, > - KFREE_DRAIN_JIFFIES); > + if (need_offload_krc(krcp)) > + schedule_delayed_work_on(cpu, &krcp->monitor_work, KFREE_DRAIN_JIFFIES); > raw_spin_unlock_irqrestore(&krcp->lock, flags); > } > }
diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c index 5445b19b48408..7919d7b48fa6a 100644 --- a/kernel/rcu/tree.c +++ b/kernel/rcu/tree.c @@ -3216,7 +3216,6 @@ struct kfree_rcu_cpu_work { * @krw_arr: Array of batches of kfree_rcu() objects waiting for a grace period * @lock: Synchronize access to this structure * @monitor_work: Promote @head to @head_free after KFREE_DRAIN_JIFFIES - * @monitor_todo: Tracks whether a @monitor_work delayed work is pending * @initialized: The @rcu_work fields have been initialized * @count: Number of objects for which GP not started * @bkvcache: @@ -3241,7 +3240,6 @@ struct kfree_rcu_cpu { struct kfree_rcu_cpu_work krw_arr[KFREE_N_BATCHES]; raw_spinlock_t lock; struct delayed_work monitor_work; - bool monitor_todo; bool initialized; int count; @@ -3421,6 +3419,18 @@ static void kfree_rcu_work(struct work_struct *work) } } +static bool +need_offload_krc(struct kfree_rcu_cpu *krcp) +{ + int i; + + for (i = 0; i < FREE_N_CHANNELS; i++) + if (krcp->bkvhead[i]) + return true; + + return !!krcp->head; +} + /* * This function is invoked after the KFREE_DRAIN_JIFFIES timeout. */ @@ -3477,9 +3487,7 @@ static void kfree_rcu_monitor(struct work_struct *work) // of the channels that is still busy we should rearm the // work to repeat an attempt. Because previous batches are // still in progress. - if (!krcp->bkvhead[0] && !krcp->bkvhead[1] && !krcp->head) - krcp->monitor_todo = false; - else + if (need_offload_krc(krcp)) schedule_delayed_work(&krcp->monitor_work, KFREE_DRAIN_JIFFIES); raw_spin_unlock_irqrestore(&krcp->lock, flags); @@ -3667,11 +3675,8 @@ void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func) WRITE_ONCE(krcp->count, krcp->count + 1); // Set timer to drain after KFREE_DRAIN_JIFFIES. - if (rcu_scheduler_active == RCU_SCHEDULER_RUNNING && - !krcp->monitor_todo) { - krcp->monitor_todo = true; + if (rcu_scheduler_active == RCU_SCHEDULER_RUNNING) schedule_delayed_work(&krcp->monitor_work, KFREE_DRAIN_JIFFIES); - } unlock_return: krc_this_cpu_unlock(krcp, flags); @@ -3746,14 +3751,8 @@ void __init kfree_rcu_scheduler_running(void) struct kfree_rcu_cpu *krcp = per_cpu_ptr(&krc, cpu); raw_spin_lock_irqsave(&krcp->lock, flags); - if ((!krcp->bkvhead[0] && !krcp->bkvhead[1] && !krcp->head) || - krcp->monitor_todo) { - raw_spin_unlock_irqrestore(&krcp->lock, flags); - continue; - } - krcp->monitor_todo = true; - schedule_delayed_work_on(cpu, &krcp->monitor_work, - KFREE_DRAIN_JIFFIES); + if (need_offload_krc(krcp)) + schedule_delayed_work_on(cpu, &krcp->monitor_work, KFREE_DRAIN_JIFFIES); raw_spin_unlock_irqrestore(&krcp->lock, flags); } }