From: Breno Leitao leitao@debian.org
[ Upstream commit 221a9c1df790fa711d65daf5ba05d0addc279153 ]
The current implementation of the netpoll system uses a global skb pool, which can lead to inefficient memory usage and waste when targets are disabled or no longer in use.
This can result in a significant amount of memory being unnecessarily allocated and retained, potentially causing performance issues and limiting the availability of resources for other system components.
Modify the netpoll system to assign a skb pool to each target instead of using a global one.
This approach allows for more fine-grained control over memory allocation and deallocation, ensuring that resources are only allocated and retained as needed.
Signed-off-by: Breno Leitao leitao@debian.org Link: https://patch.msgid.link/20241114-skb_buffers_v2-v3-1-9be9f52a8b69@debian.or... Signed-off-by: Jakub Kicinski kuba@kernel.org Stable-dep-of: 49c8d2c1f94c ("net: netpoll: fix incorrect refcount handling causing incorrect cleanup") Signed-off-by: Sasha Levin sashal@kernel.org --- include/linux/netpoll.h | 1 + net/core/netpoll.c | 31 +++++++++++++------------------ 2 files changed, 14 insertions(+), 18 deletions(-)
diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h index 959a4daacea1f..b34301650c479 100644 --- a/include/linux/netpoll.h +++ b/include/linux/netpoll.h @@ -32,6 +32,7 @@ struct netpoll { bool ipv6; u16 local_port, remote_port; u8 remote_mac[ETH_ALEN]; + struct sk_buff_head skb_pool; };
struct netpoll_info { diff --git a/net/core/netpoll.c b/net/core/netpoll.c index 87182a4272bfd..76bdb6ce46378 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -45,9 +45,6 @@
#define MAX_UDP_CHUNK 1460 #define MAX_SKBS 32 - -static struct sk_buff_head skb_pool; - #define USEC_PER_POLL 50
#define MAX_SKB_SIZE \ @@ -234,20 +231,23 @@ void netpoll_poll_enable(struct net_device *dev) up(&ni->dev_lock); }
-static void refill_skbs(void) +static void refill_skbs(struct netpoll *np) { + struct sk_buff_head *skb_pool; struct sk_buff *skb; unsigned long flags;
- spin_lock_irqsave(&skb_pool.lock, flags); - while (skb_pool.qlen < MAX_SKBS) { + skb_pool = &np->skb_pool; + + spin_lock_irqsave(&skb_pool->lock, flags); + while (skb_pool->qlen < MAX_SKBS) { skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC); if (!skb) break;
- __skb_queue_tail(&skb_pool, skb); + __skb_queue_tail(skb_pool, skb); } - spin_unlock_irqrestore(&skb_pool.lock, flags); + spin_unlock_irqrestore(&skb_pool->lock, flags); }
static void zap_completion_queue(void) @@ -284,12 +284,12 @@ static struct sk_buff *find_skb(struct netpoll *np, int len, int reserve) struct sk_buff *skb;
zap_completion_queue(); - refill_skbs(); + refill_skbs(np); repeat:
skb = alloc_skb(len, GFP_ATOMIC); if (!skb) - skb = skb_dequeue(&skb_pool); + skb = skb_dequeue(&np->skb_pool);
if (!skb) { if (++count < 10) { @@ -678,6 +678,8 @@ int netpoll_setup(struct netpoll *np) struct in_device *in_dev; int err;
+ skb_queue_head_init(&np->skb_pool); + rtnl_lock(); if (np->dev_name[0]) { struct net *net = current->nsproxy->net_ns; @@ -778,7 +780,7 @@ int netpoll_setup(struct netpoll *np) }
/* fill up the skb queue */ - refill_skbs(); + refill_skbs(np);
err = __netpoll_setup(np, ndev); if (err) @@ -804,13 +806,6 @@ int netpoll_setup(struct netpoll *np) } EXPORT_SYMBOL(netpoll_setup);
-static int __init netpoll_init(void) -{ - skb_queue_head_init(&skb_pool); - return 0; -} -core_initcall(netpoll_init); - static void rcu_cleanup_netpoll_info(struct rcu_head *rcu_head) { struct netpoll_info *npinfo =