From nobody Mon Apr 6 10:46:13 2026 Received: from angie.orcam.me.uk (angie.orcam.me.uk [78.133.224.34]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 27F5C2DF14C; Sun, 29 Mar 2026 12:32:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.133.224.34 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774787549; cv=none; b=gWVI6ssxg/6rXmh0cR+dWHL7JfOPX5JP69IyDC7BPMpefzJ75qagMJqemIMw1CWn9fX+32Q7keChtZqUhex36TMOvCp7E6i6UfITOO5R6eDJGtLA3MLNQI7uyZ36fIErR22y+9ZlqDJ5u01/tPXhMoMyb2YKhFdqg29vOREq/LU= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774787549; c=relaxed/simple; bh=n6AudPinwzF+PoAcpbD8rWgYmTs3P0AQRN0xUrqvZTs=; h=Date:From:To:cc:Subject:Message-ID:MIME-Version:Content-Type; b=LQgHUG/XdCmypBCmpnWsD6Mm5Jr3jY1RPLfBSCQi2+qm0RfGzET9q13pCfhc7gp6HiZ4M8uZidwBIm+VRPTtYXwtiomD5qKvSfxC9HXEvnsWY84Hpyugtiu1IKLfP7tVRcNeZHas67H1jEoQk5oJs6D0Va59d9RuohUWysUoIso= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=orcam.me.uk; spf=none smtp.mailfrom=orcam.me.uk; arc=none smtp.client-ip=78.133.224.34 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=orcam.me.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=orcam.me.uk Received: by angie.orcam.me.uk (Postfix, from userid 500) id 8D27B92009C; Sun, 29 Mar 2026 14:32:25 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by angie.orcam.me.uk (Postfix) with ESMTP id 7E5F392009B; Sun, 29 Mar 2026 13:32:25 +0100 (BST) Date: Sun, 29 Mar 2026 13:32:25 +0100 (BST) From: "Maciej W. Rozycki" To: Andrew Lunn , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni cc: netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH net-next] FDDI: defxx: Rate-limit memory allocation errors Message-ID: User-Agent: Alpine 2.21 (DEB 202 2017-01-01) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" Prevent the system from becoming unstable or unusable due to a flood of=20 memory allocation error messages under memory pressure, e.g.: [...] fddi0: Could not allocate receive buffer. Dropping packet. fddi0: Could not allocate receive buffer. Dropping packet. fddi0: Could not allocate receive buffer. Dropping packet. fddi0: Could not allocate receive buffer. Dropping packet. rcu: INFO: rcu_sched self-detected stall on CPU rcu: 0-...!: (332 ticks this GP) idle=3D255c/1/0x40000000 softirq=3D164201= 23/16420123 fqs=3D0 rcu: (t=3D2103 jiffies g=3D35680089 q=3D4 ncpus=3D1) rcu: rcu_sched kthread timer wakeup didn't happen for 2102 jiffies! g356800= 89 f0x0 RCU_GP_WAIT_FQS(5) ->state=3D0x402 rcu: Possible timer handling issue on cpu=3D0 timer-softirq=3D12779658 rcu: rcu_sched kthread starved for 2103 jiffies! g35680089 f0x0 RCU_GP_WAIT= _FQS(5) ->state=3D0x402 ->cpu=3D0 rcu: Unless rcu_sched kthread gets sufficient CPU time, OOM is now expecte= d behavior. rcu: RCU grace-period kthread stack dump: task:rcu_sched state:I stack:0 pid:14 tgid:14 ppid:2 f= lags:0x00004000 Call Trace: __schedule+0x258/0x580 schedule+0x19/0xa0 schedule_timeout+0x4a/0xb0 ? hrtimers_cpu_dying+0x1b0/0x1b0 rcu_gp_fqs_loop+0xb1/0x450 rcu_gp_kthread+0x9d/0x130 kthread+0xb2/0xe0 ? rcu_gp_init+0x4a0/0x4a0 ? kthread_park+0x90/0x90 ret_from_fork+0x2d/0x50 ? kthread_park+0x90/0x90 ret_from_fork_asm+0x12/0x20 entry_INT80_32+0x10d/0x10d CPU: 0 UID: 500 PID: 21895 Comm: 31370.exe Not tainted 6.13.0-dirty #2 (here running the libstdc++-v3 testsuite). Signed-off-by: Maciej W. Rozycki Reviewed-by: Andrew Lunn --- drivers/net/fddi/defxx.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) linux-defxx-ratelimit.diff Index: linux-macro/drivers/net/fddi/defxx.c =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D --- linux-macro.orig/drivers/net/fddi/defxx.c +++ linux-macro/drivers/net/fddi/defxx.c @@ -3182,7 +3182,7 @@ static void dfx_rcv_queue_process( pkt_len + 3); if (skb =3D=3D NULL) { - printk("%s: Could not allocate receive buffer. Dropping packet.\n", = bp->dev->name); + printk_ratelimited("%s: Could not allocate receive buffer. Dropping = packet.\n", bp->dev->name); bp->rcv_discards++; break; }