From: Stephen Hemminger <stephen@networkplumber.org>
To: Konstantin Ananyev <konstantin.v.ananyev@yandex.ru>
Cc: Marat Khalili <qm2k21@gmail.com>,
Konstantin Ananyev <konstantin.ananyev@huawei.com>,
dev@dpdk.org
Subject: Re: [PATCH v2 2/9] bpf: document ethdev callback threading limitations
Date: Mon, 19 Oct 2026 16:35:18 -0700 [thread overview]
Message-ID: <20261019163518.1b6fd3c7@phoenix.local> (raw)
In-Reply-To: <e5ff5f2b-de4c-48a7-bc0d-3a7392bb6e1a@yandex.ru>
On Mon, 19 Oct 2026 22:10:11 +0100
Konstantin Ananyev <konstantin.v.ananyev@yandex.ru> wrote:
> > Document the data plane limitation in the file docstring of
> > rte_bpf_ethdev.h: packet callback execution expects only one
> > thread per port/queue pair at a time, making concurrent bursts
> > (such as with RTE_ETH_TX_OFFLOAD_MT_LOCKFREE, shared RX queues,
> > or multi-threaded software PMDs) unsupported.
> Not sure what do you mean by:
> 'shared RX queues' and 'multi-threaded software PMDs'. Can you probably
> clarify?
The restriction is that: rte_bpf_eth_tx_elf_load() can not be be used with RTE_ETH_TX_OFFLOAD_MT_LOCKFREE
because if that offload is set, application is allowed to share a single transmit queue across multiple lcore.
It would be better if the attempts to load on such a device failed.
But in the is not enough because at least in theory a user could enable
the offload later by reconfiguring the device.
next prev parent reply other threads:[~2026-10-19 23:35 UTC|newest]
Thread overview: 41+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-10-11 18:21 [PATCH 0/9] bpf: clean up and document ethdev callback synchronization Marat Khalili
2026-10-11 18:21 ` [PATCH 1/9] bpf: document packet callback unload sequence Marat Khalili
2026-10-11 18:21 ` [PATCH 2/9] bpf: document ethdev callback threading limitations Marat Khalili
2026-10-11 18:21 ` [PATCH 3/9] bpf: reject Tx callback installation with MT_LOCKFREE Marat Khalili
2026-10-11 18:21 ` [PATCH 4/9] bpf: add callback flag to skip multi-thread check Marat Khalili
2026-10-11 19:48 ` Stephen Hemminger
2026-10-11 20:12 ` Marat Khalili
2026-10-11 18:21 ` [PATCH 5/9] bpf: remove redundant memory barrier on unload Marat Khalili
2026-10-11 19:50 ` Stephen Hemminger
2026-10-11 20:14 ` Marat Khalili
2026-10-11 18:21 ` [PATCH 6/9] bpf: simplify callback inuse tracking to boolean flag Marat Khalili
2026-10-11 19:51 ` Stephen Hemminger
2026-10-11 20:17 ` Marat Khalili
2026-10-11 18:21 ` [PATCH 7/9] bpf: reformat packet callback unload diagram Marat Khalili
2026-10-11 18:21 ` [PATCH 8/9] bpf: use relaxed stores for callback inuse tracking Marat Khalili
2026-10-11 19:52 ` Stephen Hemminger
2026-10-11 20:24 ` Marat Khalili
2026-10-11 18:21 ` [PATCH 9/9] bpf: make callback handle atomic with relaxed access Marat Khalili
2026-10-11 19:54 ` Stephen Hemminger
2026-10-11 20:31 ` Marat Khalili
2026-10-11 20:29 ` [RFC] bpf: fix callback unload with concurrent Tx burst Stephen Hemminger
2026-10-12 21:09 ` [PATCH v2 0/9] bpf: clean up and document ethdev callback synchronization Marat Khalili
2026-10-12 21:09 ` [PATCH v2 1/9] bpf: document packet callback unload sequence Marat Khalili
2026-10-19 20:44 ` Konstantin Ananyev
2026-10-12 21:09 ` [PATCH v2 2/9] bpf: document ethdev callback threading limitations Marat Khalili
2026-10-12 21:44 ` Stephen Hemminger
2026-10-19 21:10 ` Konstantin Ananyev
2026-10-19 23:35 ` Stephen Hemminger [this message]
2026-10-20 6:54 ` Konstantin Ananyev
2026-10-12 21:09 ` [PATCH v2 3/9] bpf: reject Tx callback installation with MT_LOCKFREE Marat Khalili
2026-10-19 21:22 ` Konstantin Ananyev
2026-10-19 23:36 ` Stephen Hemminger
2026-10-12 21:09 ` [PATCH v2 4/9] bpf: remove redundant memory barrier on unload Marat Khalili
2026-10-12 21:09 ` [PATCH v2 5/9] bpf: simplify callback inuse tracking to boolean flag Marat Khalili
2026-10-19 20:50 ` Konstantin Ananyev
2026-10-12 21:09 ` [PATCH v2 6/9] bpf: reformat packet callback unload diagram Marat Khalili
2026-10-12 21:09 ` [PATCH v2 7/9] bpf: use relaxed accesses for callback inuse tracking Marat Khalili
2026-10-12 21:09 ` [PATCH v2 8/9] bpf: make callback handle atomic with relaxed access Marat Khalili
2026-10-19 21:27 ` Konstantin Ananyev
2026-10-12 21:09 ` [PATCH v2 9/9] bpf: add callback flag to skip multi-thread check Marat Khalili
2026-10-13 16:55 ` Stephen Hemminger
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