Hello, Zqiang.
See below some nits:
>
> Add free per-cpu existing krcp's page cache operation, when
> the system is under memory pressure.
>
> Signed-off-by: Zqiang <qiang.zhang@xxxxxxxxxxxxx>
> ---
> kernel/rcu/tree.c | 26 ++++++++++++++++++++++++++
> 1 file changed, 26 insertions(+)
>
> diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c
> index c1ae1e52f638..4e1c14b12bdd 100644
> --- a/kernel/rcu/tree.c
> +++ b/kernel/rcu/tree.c
> @@ -3571,17 +3571,41 @@ void kvfree_call_rcu(struct rcu_head *head, rcu_callback_t func)
> }
> EXPORT_SYMBOL_GPL(kvfree_call_rcu);
>
> +static inline int free_krc_page_cache(struct kfree_rcu_cpu *krcp)
Do we need it "inlined"?
> +{
> + unsigned long flags;
> + struct kvfree_rcu_bulk_data *bnode;
> + int i, num = 0;
> +
> + for (i = 0; i < rcu_min_cached_objs; i++) {
> + raw_spin_lock_irqsave(&krcp->lock, flags);
> + bnode = get_cached_bnode(krcp);
> + raw_spin_unlock_irqrestore(&krcp->lock, flags);
> + if (!bnode)
> + break;
> + free_page((unsigned long)bnode);
> + num++;
> + }
> +
> + return num;
Get rid of "num" and return i instead?
> +}
> +
> static unsigned long
> kfree_rcu_shrink_count(struct shrinker *shrink, struct shrink_control *sc)
> {
> int cpu;
> unsigned long count = 0;
> + unsigned long flags;
>
> /* Snapshot count of all CPUs */
> for_each_possible_cpu(cpu) {
> struct kfree_rcu_cpu *krcp = per_cpu_ptr(&krc, cpu);
>
> count += READ_ONCE(krcp->count);
> +
> + raw_spin_lock_irqsave(&krcp->lock, flags);
> + count += krcp->nr_bkv_objs;
> + raw_spin_unlock_irqrestore(&krcp->lock, flags);
> }
>
> return count;
> @@ -3604,6 +3628,8 @@ kfree_rcu_shrink_scan(struct shrinker *shrink, struct shrink_control *sc)
> else
> raw_spin_unlock_irqrestore(&krcp->lock, flags);
>
> + count += free_krc_page_cache(krcp);
Move it upper right after count = krcp->count;, so a "count" is set
in one place what i more readable and clear?
Thank you!
--
Vlad Rezki
