Update from upstream with manual merge of Yasunori Goto's

changes to swiotlb.c made in commit 281dd25cdc0d6903929b79183816d151ea626341
since this file has been moved from arch/ia64/lib/swiotlb.c to
lib/swiotlb.c

Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 12 insertions, 1 deletions

diff --git a/kernel/rcupdate.c b/kernel/rcupdate.c
index bef3b6901b76..2559d4b8f23f 100644
--- a/kernel/rcupdate.c
+++ b/kernel/rcupdate.c
@@ -71,7 +71,7 @@ DEFINE_PER_CPU(struct rcu_data, rcu_bh_data) = { 0L };
 
 /* Fake initialization required by compiler */
 static DEFINE_PER_CPU(struct tasklet_struct, rcu_tasklet) = {NULL};
-static int maxbatch = 10;
+static int maxbatch = 10000;
 
 #ifndef __HAVE_ARCH_CMPXCHG
 /*
@@ -109,6 +109,10 @@ void fastcall call_rcu(struct rcu_head *head,
         rdp = &__get_cpu_var(rcu_data);
         *rdp->nxttail = head;
         rdp->nxttail = &head->next;
+
+        if (unlikely(++rdp->count > 10000))
+                set_need_resched();
+
         local_irq_restore(flags);
 }
 
@@ -140,6 +144,12 @@ void fastcall call_rcu_bh(struct rcu_head *head,
         rdp = &__get_cpu_var(rcu_bh_data);
         *rdp->nxttail = head;
         rdp->nxttail = &head->next;
+        rdp->count++;
+/*
+ *  Should we directly call rcu_do_batch() here ?
+ *  if (unlikely(rdp->count > 10000))
+ *      rcu_do_batch(rdp);
+ */
         local_irq_restore(flags);
 }
 
@@ -157,6 +167,7 @@ static void rcu_do_batch(struct rcu_data *rdp)
                 next = rdp->donelist = list->next;
                 list->func(list);
                 list = next;
+                rdp->count--;
                 if (++count >= maxbatch)
                         break;
         }