target/linux/generic/backport-6.1/610-v6.3-net-page_pool-use-in_softirq-instead.patch

   1 From: Qingfang DENG <qingfang.deng@siflower.com.cn>
   2 Date: Fri, 3 Feb 2023 09:16:11 +0800
   3 Subject: [PATCH] net: page_pool: use in_softirq() instead
   4
   5 We use BH context only for synchronization, so we don't care if it's
   6 actually serving softirq or not.
   7
   8 As a side node, in case of threaded NAPI, in_serving_softirq() will
   9 return false because it's in process context with BH off, making
  10 page_pool_recycle_in_cache() unreachable.
  11
  12 Signed-off-by: Qingfang DENG <qingfang.deng@siflower.com.cn>
  13 ---
  14
  15 --- a/include/net/page_pool.h
  16 +++ b/include/net/page_pool.h
  17 @@ -386,7 +386,7 @@ static inline void page_pool_nid_changed
  18  static inline void page_pool_ring_lock(struct page_pool *pool)
  19         __acquires(&pool->ring.producer_lock)
  20  {
  21 -       if (in_serving_softirq())
  22 +       if (in_softirq())
  23                 spin_lock(&pool->ring.producer_lock);
  24         else
  25                 spin_lock_bh(&pool->ring.producer_lock);
  26 @@ -395,7 +395,7 @@ static inline void page_pool_ring_lock(s
  27  static inline void page_pool_ring_unlock(struct page_pool *pool)
  28         __releases(&pool->ring.producer_lock)
  29  {
  30 -       if (in_serving_softirq())
  31 +       if (in_softirq())
  32                 spin_unlock(&pool->ring.producer_lock);
  33         else
  34                 spin_unlock_bh(&pool->ring.producer_lock);
  35 --- a/net/core/page_pool.c
  36 +++ b/net/core/page_pool.c
  37 @@ -511,8 +511,8 @@ static void page_pool_return_page(struct
  38  static bool page_pool_recycle_in_ring(struct page_pool *pool, struct page *page)
  39  {
  40         int ret;
  41 -       /* BH protection not needed if current is serving softirq */
  42 -       if (in_serving_softirq())
  43 +       /* BH protection not needed if current is softirq */
  44 +       if (in_softirq())
  45                 ret = ptr_ring_produce(&pool->ring, page);
  46         else
  47                 ret = ptr_ring_produce_bh(&pool->ring, page);
  48 @@ -570,7 +570,7 @@ __page_pool_put_page(struct page_pool *p
  49                         page_pool_dma_sync_for_device(pool, page,
  50                                                       dma_sync_size);
  51
  52 -               if (allow_direct && in_serving_softirq() &&
  53 +               if (allow_direct && in_softirq() &&
  54                     page_pool_recycle_in_cache(page, pool))
  55                         return NULL;
  56