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Mina Almasry says: ==================== Device memory TCP TX The TX path had been dropped from the Device Memory TCP patch series post RFCv1 [1], to make that series slightly easier to review. This series rebases the implementation of the TX path on top of the net_iov/netmem framework agreed upon and merged. The motivation for the feature is thoroughly described in the docs & cover letter of the original proposal, so I don't repeat the lengthy descriptions here, but they are available in [1]. Full outline on usage of the TX path is detailed in the documentation included with this series. Test example is available via the kselftest included in the series as well. The series is relatively small, as the TX path for this feature largely piggybacks on the existing MSG_ZEROCOPY implementation. Patch Overview: --------------- 1. Documentation & tests to give high level overview of the feature being added. 1. Add netmem refcounting needed for the TX path. 2. Devmem TX netlink API. 3. Devmem TX net stack implementation. 4. Make dma-buf unbinding scheduled work to handle TX cases where it gets freed from contexts where we can't sleep. 5. Add devmem TX documentation. 6. Add scaffolding enabling driver support for netmem_tx. Add helpers, driver feature flag, and docs to enable drivers to declare netmem_tx support. 7. Guard netmem_tx against being enabled against drivers that don't support it. 8. Add devmem_tx selftests. Add TX path to ncdevmem and add a test to devmem.py. Testing: -------- Testing is very similar to devmem TCP RX path. The ncdevmem test used for the RX path is now augemented with client functionality to test TX path. * Test Setup: Kernel: net-next with this RFC and memory provider API cherry-picked locally. Hardware: Google Cloud A3 VMs. NIC: GVE with header split & RSS & flow steering support. Performance results are not included with this version, unfortunately. I'm having issues running the dma-buf exporter driver against the upstream kernel on my test setup. The issues are specific to that dma-buf exporter and do not affect this patch series. I plan to follow up this series with perf fixes if the tests point to issues once they're up and running. Special thanks to Stan who took a stab at rebasing the TX implementation on top of the netmem/net_iov framework merged. Parts of his proposal [2] that are reused as-is are forked off into their own patches to give full credit. [1] https://lore.kernel.org/netdev/20240909054318.1809580-1-almasrymina@google.com/ [2] https://lore.kernel.org/netdev/20240913150913.1280238-2-sdf@fomichev.me/T/#m066dd407fbed108828e2c40ae50e3f4376ef57fd Cc: sdf@fomichev.me Cc: asml.silence@gmail.com Cc: dw@davidwei.uk Cc: Jamal Hadi Salim <jhs@mojatatu.com> Cc: Victor Nogueira <victor@mojatatu.com> Cc: Pedro Tammela <pctammela@mojatatu.com> Cc: Samiullah Khawaja <skhawaja@google.com> Cc: Kuniyuki Iwashima <kuniyu@amazon.com> v14: https://lore.kernel.org/netdev/20250429032645.363766-1-almasrymina@google.com/ v13: https://lore.kernel.org/netdev/20250425204743.617260-1-almasrymina@google.com/ v12: https://lore.kernel.org/netdev/20250423031117.907681-1-almasrymina@google.com/ v11: https://lore.kernel.org/netdev/20250423031117.907681-1-almasrymina@google.com/ v10: https://lore.kernel.org/netdev/20250417231540.2780723-1-almasrymina@google.com/ v9: https://lore.kernel.org/netdev/20250415224756.152002-1-almasrymina@google.com/ v8: https://lore.kernel.org/netdev/20250308214045.1160445-1-almasrymina@google.com/ v7: https://lore.kernel.org/netdev/20250227041209.2031104-1-almasrymina@google.com/ v6: https://lore.kernel.org/netdev/20250222191517.743530-1-almasrymina@google.com/ v5: https://lore.kernel.org/netdev/20250220020914.895431-1-almasrymina@google.com/ v4: https://lore.kernel.org/netdev/20250203223916.1064540-1-almasrymina@google.com/ v3: https://patchwork.kernel.org/project/netdevbpf/list/?series=929401&state=* RFC v2: https://patchwork.kernel.org/project/netdevbpf/list/?series=920056&state=* ==================== Link: https://patch.msgid.link/20250508004830.4100853-1-almasrymina@google.com Signed-off-by: Paolo Abeni <pabeni@redhat.com>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
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https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the reStructuredText markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.