net: core: another layer of lists, around PF_MEMALLOC skb handling
First example of a layer splitting the list (rather than merely taking
individual packets off it).
Involves new list.h function, list_cut_before(), like list_cut_position()
but cuts on the other side of the given entry.
Signed-off-by: Edward Cree <ecree@solarflare.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/core/dev.c b/net/core/dev.c
index 1e87361..9aadef9 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c
@@ -4784,6 +4784,14 @@ int netif_receive_skb_core(struct sk_buff *skb)
}
EXPORT_SYMBOL(netif_receive_skb_core);
+static void __netif_receive_skb_list_core(struct list_head *head, bool pfmemalloc)
+{
+ struct sk_buff *skb, *next;
+
+ list_for_each_entry_safe(skb, next, head, list)
+ __netif_receive_skb_core(skb, pfmemalloc);
+}
+
static int __netif_receive_skb(struct sk_buff *skb)
{
int ret;
@@ -4809,6 +4817,34 @@ static int __netif_receive_skb(struct sk_buff *skb)
return ret;
}
+static void __netif_receive_skb_list(struct list_head *head)
+{
+ unsigned long noreclaim_flag = 0;
+ struct sk_buff *skb, *next;
+ bool pfmemalloc = false; /* Is current sublist PF_MEMALLOC? */
+
+ list_for_each_entry_safe(skb, next, head, list) {
+ if ((sk_memalloc_socks() && skb_pfmemalloc(skb)) != pfmemalloc) {
+ struct list_head sublist;
+
+ /* Handle the previous sublist */
+ list_cut_before(&sublist, head, &skb->list);
+ __netif_receive_skb_list_core(&sublist, pfmemalloc);
+ pfmemalloc = !pfmemalloc;
+ /* See comments in __netif_receive_skb */
+ if (pfmemalloc)
+ noreclaim_flag = memalloc_noreclaim_save();
+ else
+ memalloc_noreclaim_restore(noreclaim_flag);
+ }
+ }
+ /* Handle the remaining sublist */
+ __netif_receive_skb_list_core(head, pfmemalloc);
+ /* Restore pflags */
+ if (pfmemalloc)
+ memalloc_noreclaim_restore(noreclaim_flag);
+}
+
static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
{
struct bpf_prog *old = rtnl_dereference(dev->xdp_prog);
@@ -4843,14 +4879,6 @@ static int generic_xdp_install(struct net_device *dev, struct netdev_bpf *xdp)
return ret;
}
-static void __netif_receive_skb_list(struct list_head *head)
-{
- struct sk_buff *skb, *next;
-
- list_for_each_entry_safe(skb, next, head, list)
- __netif_receive_skb(skb);
-}
-
static int netif_receive_skb_internal(struct sk_buff *skb)
{
int ret;