From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 72E1E3F9D2; Fri, 21 Nov 2025 13:33:51 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763732031; cv=none; b=fc6EdxzvEtje0Ld3fMDEhhzv5jNHa9AME4b0Bf4TWHWJwU+4Cyv66l6Sn727DOrR11eGYeWCDcpImq8XCZpGrWCWTIHL6PaSOqoLDgxojA5NOH6JT7OxVcnvVgJTUeB75NW19271RZdJmau2K3miFD5qzVBUJNZ2SbYodmkszDY= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1763732031; c=relaxed/simple; bh=z8cYRqaO3kN/Umzoz7ukhhpT2HhyQFdJtAsLHi2g+po=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=fOe/aYA50bQjCS2Fjyk6b2V2XlC7MDNN9/l9RL+CsNfAMqSy1uP3jsmdVFKEEOrAiWSDIbgUzUuE59f7Ow/0c56Kirj8pZHaCgAvLATkwKj4zdMVVwc2RBQKftC485YJnnqroPlbP3Kx1CCyV+YB/UvBDJ0qHpqOTU58SFKPuEE= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b=xMmIigNv; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linuxfoundation.org header.i=@linuxfoundation.org header.b="xMmIigNv" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 8A994C4CEF1; Fri, 21 Nov 2025 13:33:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1763732030; bh=z8cYRqaO3kN/Umzoz7ukhhpT2HhyQFdJtAsLHi2g+po=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=xMmIigNvIJgBVORjJVOIeHqBW7ok+80W30+EYf2yf98TFkp8HOAyzsg3ROYpMfFeb Q2eJUi2mg/vlqLJh27iEB4nV8mIcFT1aJhsWwMk4B1PO1U2ddlgnbO7iaABhKON/un 6HNu9/lJ+l42yIwaI2Pcf6UmMdxXHCz8pNvCp63o= From: Greg Kroah-Hartman To: stable@vger.kernel.org Cc: Greg Kroah-Hartman , patches@lists.linux.dev, Breno Leitao , Jakub Kicinski , Sasha Levin Subject: [PATCH 6.12 166/185] net: netpoll: Individualize the skb pool Date: Fri, 21 Nov 2025 14:13:13 +0100 Message-ID: <20251121130149.869999916@linuxfoundation.org> X-Mailer: git-send-email 2.52.0 In-Reply-To: <20251121130143.857798067@linuxfoundation.org> References: <20251121130143.857798067@linuxfoundation.org> User-Agent: quilt/0.69 X-stable: review X-Patchwork-Hint: ignore Precedence: bulk X-Mailing-List: stable@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit 6.12-stable review patch. If anyone has any objections, please let me know. ------------------ From: Breno Leitao [ 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 Link: https://patch.msgid.link/20241114-skb_buffers_v2-v3-1-9be9f52a8b69@debian.org Signed-off-by: Jakub Kicinski Stable-dep-of: 49c8d2c1f94c ("net: netpoll: fix incorrect refcount handling causing incorrect cleanup") Signed-off-by: Sasha Levin Signed-off-by: Greg Kroah-Hartman --- include/linux/netpoll.h | 1 + net/core/netpoll.c | 31 +++++++++++++------------------ 2 files changed, 14 insertions(+), 18 deletions(-) --- 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 { --- 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_devi 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 n 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 @@ put_noaddr: } /* fill up the skb queue */ - refill_skbs(); + refill_skbs(np); err = __netpoll_setup(np, ndev); if (err) @@ -804,13 +806,6 @@ unlock: } 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 =