On Tue, Apr 18, 2023 at 08:27:02PM +0800, Zqiang wrote: > If the rcu_min_cached_objs is set to zero at boot params, the > krcp->page_cache_work will not be triggered to fill page cache, > and the put_cached_bnode() also does not fill page cache, this > also means the krcp->bkvcache is always empty, so not need to > acquire unnecessary krcp->lock to get page from krcp->bkvcache, > this commit therefore make drain_page_cache() return directly if > the rcu_min_cached_objs is zero. > > Signed-off-by: Zqiang <qiang1.zhang@xxxxxxxxx> > --- > kernel/rcu/tree.c | 3 +++ > 1 file changed, 3 insertions(+) > > diff --git a/kernel/rcu/tree.c b/kernel/rcu/tree.c > index 93faf9f5c58f..00620a2117de 100644 > --- a/kernel/rcu/tree.c > +++ b/kernel/rcu/tree.c > @@ -2924,6 +2924,9 @@ drain_page_cache(struct kfree_rcu_cpu *krcp) > struct llist_node *page_list, *pos, *n; > int freed = 0; > > + if (!rcu_min_cached_objs) > + return 0; > + > raw_spin_lock_irqsave(&krcp->lock, flags); > page_list = llist_del_all(&krcp->bkvcache); > WRITE_ONCE(krcp->nr_bkv_objs, 0); > -- > 2.32.0 > Reviewed-by: Uladzislau Rezki (Sony) <urezki@xxxxxxxxx> -- Uladzislau Rezki
