From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from stravinsky.debian.org (stravinsky.debian.org [82.195.75.108]) (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 158D3480978; Thu, 2 Jul 2026 12:20:45 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=82.195.75.108 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782994847; cv=none; b=PoIOu3/EVkEJ9wZmO15mviXnirkJcmJdA7DmwL8gnHQ3PU2Tli0GbKTfKoXo6wBPqUZF56lJpNoiTwHNOLsAfpR/7SA//OSuVNUjPrQilX7m1wxHphIxBqf8ExINVtGPOZgvZxqTLG4TFpiEWuReGeRqwnUldB1rNi6OPkUIYZ8= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782994847; c=relaxed/simple; bh=/xwUC3EdhFnukKRYH9jrqkNKUElM9MbOZrLoFAsdE/w=; h=From:Date:Subject:MIME-Version:Content-Type:Message-Id:References: In-Reply-To:To:Cc; b=fMBdJYG+tbE1PFj1aaXzPqeiZOPEg9qsgkSf8vgpgPNHs7bEF7KcWgkfHbPQO1sxlNq/BqQjkTA5eO3P2i288eVIx/YYJk4V38LnY7m/p8T+bj70CedmjRfWxGe94s2sJbU0HNIKGHjCVKUjsMZgycCj8tuI5nc7qlMjTGapPKw= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org; spf=pass smtp.mailfrom=debian.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b=IkTRDrIQ; arc=none smtp.client-ip=82.195.75.108 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=debian.org Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=debian.org Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=debian.org header.i=@debian.org header.b="IkTRDrIQ" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=debian.org; s=smtpauto.stravinsky; h=X-Debian-User:Cc:To:In-Reply-To:References: Message-Id:Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date: From:Reply-To:Content-ID:Content-Description; bh=YNpLN13LP9HQufU7hminbv7Sx8jX4+J/DmkudT8hh5s=; b=IkTRDrIQC17bKi3cnk89wIrl/b ILFNVcuXPY/KvZ3nrhtEB4xWxl1JySWvpAz+lAIe2eUB1AbqQzenxqXCFBY82j4gzGu4IGdBql23L UPLgcj53AwmGQeQOEtjkTxMlQZ0dy/DMxnqnMVm0F0TIFND8V7kC2ElD6jMaQmg+ac4oHywJ+FxAo XbuDkauf/gs+4ml6nxxi8xbOlb+34nN07rbN6qKz8RWdVIAEUjki+toQZb/INyH4i+600n0dY08Jj acd0iHJLGsW+2gpPCWHr4Czz9Ljq5A1IN1V8N5t5qqQnsGZWlTqJFjjg9ZKsQFgDlZUu4YvIHoCDM s8tYrmhQ==; Received: from authenticated-user by stravinsky.debian.org with esmtpsa (TLS1.3:ECDHE_X25519__RSA_PSS_RSAE_SHA256__AES_256_GCM:256) (Exim 4.96) (envelope-from ) id 1wfGPK-008cQq-0a; Thu, 02 Jul 2026 12:20:42 +0000 From: Breno Leitao Date: Thu, 02 Jul 2026 05:19:48 -0700 Subject: [PATCH net-next v2 4/8] netconsole: move refill_skbs() and skb-pool sizing macros from netpoll Precedence: bulk X-Mailing-List: netdev@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Message-Id: <20260702-netconsole_move_more-v2-4-1ebedd921dcb@debian.org> References: <20260702-netconsole_move_more-v2-0-1ebedd921dcb@debian.org> In-Reply-To: <20260702-netconsole_move_more-v2-0-1ebedd921dcb@debian.org> To: "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni , Simon Horman , Andrew Lunn Cc: netdev@vger.kernel.org, asantostc@gmail.com, gustavold@gmail.com, linux-kernel@vger.kernel.org, Breno Leitao , kernel-team@meta.com X-Mailer: b4 0.14.3 X-Developer-Signature: v=1; a=openpgp-sha256; l=4632; i=leitao@debian.org; h=from:subject:message-id; bh=/xwUC3EdhFnukKRYH9jrqkNKUElM9MbOZrLoFAsdE/w=; b=owEBbQKS/ZANAwAIATWjk5/8eHdtAcsmYgBqRleFpQ5wHFoZ3JraFXBiq6+TiSKH7kUixydm0 KdlkJOJCHKJAjMEAAEIAB0WIQSshTmm6PRnAspKQ5s1o5Of/Hh3bQUCakZXhQAKCRA1o5Of/Hh3 bXNcD/9whUIqhZqhT3CzP3uG112U2z0ay7Msg6U9xKSyx8HIyuTAfUIS9ceUG02s5uRnyvpVdWs I57B2k/6uNhdtO1gcnhvisaIQjmSr3HOH4OvJqZIx7Erjoc8e73KQEVSKhESGz4ZWfNqJ2L9bqP jcSq1uv43RRmzbzsBB/u24a0iks1TFsmunIkPUx9fx8tw/6JrUKw8ngeoeABCsVpVLeC1Hx65Fx qXkkPt6OKdcHXgTOJZLc8QpBPNi9EyEwnVWNSPi6KbfH2o5jKB0mLQaadmoQBbgbrWHJm+wfwm9 qqGpgvYC+QbTtPSLMXWhe154Kum4YYK75VgVROr1cmnE8ktEdRdKuj60bmmGo/FNSKui+ZyvgQR OYUyshYaUAbEKnAf65F0BTyKuRH1sSSRDOin5bu/njSIkdmQ8IqaX2fJxbOP6Es554TiMM2f5Zv rrB7tdpQxnEcjvTdYrGVh/YebhKd0OpEAoNrsp6rBeT325rNcF+/9cIA3QD/4GLxv1cmGVU3uHa RYnBobDWpO2/SuV8n3KgoFmMqqEXPG9UeL74/KPDbKqprlrJ4lOoWA5hI6IPj3mVIFQ1kBj0cLT hJzm+y+FNC3+xBwYTJ8oGARDslQcsYF+8CYRgJoNbVqKSi98gpcgj+2NdzGzkoplxLEub7PWb1H 4ohtK9k4A3oU1uw== X-Developer-Key: i=leitao@debian.org; a=openpgp; fpr=AC8539A6E8F46702CA4A439B35A3939FFC78776D X-Debian-User: leitao refill_skbs() is now only called from netconsole (directly via netconsole_skb_pool_init() and indirectly via the just-moved refill_skbs_work_handler()), and the MAX_UDP_CHUNK / MAX_SKBS / MAX_SKB_SIZE macros are private to it. Move them all into drivers/net/netconsole.c. MAX_UDP_CHUNK and MAX_SKB_SIZE were promoted to by commit 6c537b845c99 ("netconsole: do not dequeue pooled skbs that cannot satisfy len") so find_skb() could detect oversized requests against the same value refill_skbs() used. With both functions now local to netconsole, the shared definition no longer needs to live in the header. Pure code motion: bodies and pool sizing semantics are unchanged. Signed-off-by: Breno Leitao --- drivers/net/netconsole.c | 29 +++++++++++++++++++++++++++++ include/linux/netpoll.h | 15 --------------- net/core/netpoll.c | 23 ----------------------- 3 files changed, 29 insertions(+), 38 deletions(-) diff --git a/drivers/net/netconsole.c b/drivers/net/netconsole.c index 59b1f7d6f103a..6bb8184d023a3 100644 --- a/drivers/net/netconsole.c +++ b/drivers/net/netconsole.c @@ -61,6 +61,19 @@ MODULE_IMPORT_NS("NETDEV_INTERNAL"); #define MAX_USERDATA_ITEMS 256 #define MAX_PRINT_CHUNK 1000 +/* + * Sizing for the per-target fallback skb pool consulted by find_skb() + * when its GFP_ATOMIC allocation fails so messages still get out under + * memory pressure. + */ +#define MAX_UDP_CHUNK 1460 +#define MAX_SKBS 32 +#define MAX_SKB_SIZE \ + (sizeof(struct ethhdr) + \ + sizeof(struct iphdr) + \ + sizeof(struct udphdr) + \ + MAX_UDP_CHUNK) + static char config[MAX_PARAM_LENGTH]; module_param_string(netconsole, config, MAX_PARAM_LENGTH, 0); MODULE_PARM_DESC(netconsole, " netconsole=[src-port]@[src-ip]/[dev],[tgt-port]@/[tgt-macaddr]"); @@ -292,6 +305,22 @@ static void netcons_release_dev(struct netconsole_target *nt) memset(&nt->np.dev_name, 0, IFNAMSIZ); } +static void refill_skbs(struct netpoll *np) +{ + struct sk_buff_head *skb_pool; + struct sk_buff *skb; + + skb_pool = &np->skb_pool; + + while (READ_ONCE(skb_pool->qlen) < MAX_SKBS) { + skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC | __GFP_NOWARN); + if (!skb) + break; + + skb_queue_tail(skb_pool, skb); + } +} + static void refill_skbs_work_handler(struct work_struct *work) { struct netpoll *np = diff --git a/include/linux/netpoll.h b/include/linux/netpoll.h index 51e5863d8e678..7e2fbce863e9b 100644 --- a/include/linux/netpoll.h +++ b/include/linux/netpoll.h @@ -21,20 +21,6 @@ union inet_addr { struct in6_addr in6; }; -/* - * Maximum payload netpoll's preallocated skb pool can carry. Keep this in - * sync with the buffer size used by refill_skbs() in net/core/netpoll.c; - * callers (e.g. netconsole) use it to detect requests the pool can never - * satisfy and avoid dequeuing a pooled skb that would later trip - * skb_over_panic() in skb_put(). - */ -#define MAX_UDP_CHUNK 1460 -#define MAX_SKB_SIZE \ - (sizeof(struct ethhdr) + \ - sizeof(struct iphdr) + \ - sizeof(struct udphdr) + \ - MAX_UDP_CHUNK) - struct netpoll { struct net_device *dev; netdevice_tracker dev_tracker; @@ -90,7 +76,6 @@ void netpoll_cleanup(struct netpoll *np); void do_netpoll_cleanup(struct netpoll *np); netdev_tx_t netpoll_send_skb(struct netpoll *np, struct sk_buff *skb); void netpoll_zap_completion_queue(void); -void refill_skbs(struct netpoll *np); void skb_pool_flush(struct netpoll *np); #ifdef CONFIG_NETPOLL diff --git a/net/core/netpoll.c b/net/core/netpoll.c index 7088cf0df43ce..921699e69ac97 100644 --- a/net/core/netpoll.c +++ b/net/core/netpoll.c @@ -36,12 +36,6 @@ #include #include -/* - * We maintain a small pool of fully-sized skbs, to make sure the - * message gets out even in extreme OOM situations. - */ - -#define MAX_SKBS 32 #define USEC_PER_POLL 50 static unsigned int carrier_timeout = 4; @@ -213,23 +207,6 @@ void netpoll_poll_enable(struct net_device *dev) up(&ni->dev_lock); } -void refill_skbs(struct netpoll *np) -{ - struct sk_buff_head *skb_pool; - struct sk_buff *skb; - - skb_pool = &np->skb_pool; - - while (READ_ONCE(skb_pool->qlen) < MAX_SKBS) { - skb = alloc_skb(MAX_SKB_SIZE, GFP_ATOMIC | __GFP_NOWARN); - if (!skb) - break; - - skb_queue_tail(skb_pool, skb); - } -} -EXPORT_SYMBOL_GPL(refill_skbs); - void netpoll_zap_completion_queue(void) { unsigned long flags; -- 2.53.0-Meta