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From: Jakub Kicinski <kuba@kernel.org>
To: Jesper Dangaard Brouer <hawk@kernel.org>
Cc: netdev@vger.kernel.org, bpf@vger.kernel.org, tom@herbertland.com,
	"Eric Dumazet" <eric.dumazet@gmail.com>,
	"David S. Miller" <davem@davemloft.net>,
	"Paolo Abeni" <pabeni@redhat.com>,
	"Toke Høiland-Jørgensen" <toke@toke.dk>,
	dsahern@kernel.org, makita.toshiaki@lab.ntt.co.jp,
	kernel-team@cloudflare.com, phil@nwl.cc
Subject: Re: [PATCH net-next V4 2/2] veth: apply qdisc backpressure on full ptr_ring to reduce TX drops
Date: Wed, 16 Apr 2025 06:38:13 -0700	[thread overview]
Message-ID: <20250416063813.75fb83dc@kernel.org> (raw)
In-Reply-To: <174472470529.274639.17026526070544068280.stgit@firesoul>

On Tue, 15 Apr 2025 15:45:05 +0200 Jesper Dangaard Brouer wrote:
> In production, we're seeing TX drops on veth devices when the ptr_ring
> fills up. This can occur when NAPI mode is enabled, though it's
> relatively rare. However, with threaded NAPI - which we use in
> production - the drops become significantly more frequent.

It splats:

[ 5319.025772][ C1] dump_stack_lvl (lib/dump_stack.c:123) 
[ 5319.025786][ C1] lockdep_rcu_suspicious (kernel/locking/lockdep.c:6866) 
[ 5319.025797][ C1] veth_xdp_rcv (drivers/net/veth.c:907 (discriminator 9)) 
[ 5319.025850][ C1] veth_poll (drivers/net/veth.c:977) 
-- 
pw-bot: cr

  parent reply	other threads:[~2025-04-16 13:38 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2025-04-15 13:44 [PATCH net-next V4 0/2] veth: qdisc backpressure and qdisc check refactor Jesper Dangaard Brouer
2025-04-15 13:44 ` [PATCH net-next V4 1/2] net: sched: generalize check for no-queue qdisc on TX queue Jesper Dangaard Brouer
2025-04-15 15:43   ` David Ahern
2025-04-15 16:30     ` Jesper Dangaard Brouer
2025-04-16 13:32   ` Toke Høiland-Jørgensen
2025-04-15 13:45 ` [PATCH net-next V4 2/2] veth: apply qdisc backpressure on full ptr_ring to reduce TX drops Jesper Dangaard Brouer
2025-04-16 12:44   ` Toshiaki Makita
2025-04-17 13:00     ` Jesper Dangaard Brouer
2025-04-16 13:38   ` Jakub Kicinski [this message]
2025-04-16 13:58     ` Toke Høiland-Jørgensen
2025-04-17 10:02       ` Jesper Dangaard Brouer
2025-04-16 13:56   ` Toke Høiland-Jørgensen
2025-04-17  9:32     ` Jesper Dangaard Brouer

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