mainlining shenanigans
c1318b39c7
TLS device offload copies sendfile data to a bounce buffer before transmitting. It allows to maintain the valid MAC on TLS records when the file contents change and a part of TLS record has to be retransmitted on TCP level. In many common use cases (like serving static files over HTTPS) the file contents are not changed on the fly. In many use cases breaking the connection is totally acceptable if the file is changed during transmission, because it would be received corrupted in any case. This commit allows to optimize performance for such use cases to providing a new optional mode of TLS sendfile(), in which the extra copy is skipped. Removing this copy improves performance significantly, as TLS and TCP sendfile perform the same operations, and the only overhead is TLS header/trailer insertion. The new mode can only be enabled with the new socket option named TLS_TX_ZEROCOPY_SENDFILE on per-socket basis. It preserves backwards compatibility with existing applications that rely on the copying behavior. The new mode is safe, meaning that unsolicited modifications of the file being sent can't break integrity of the kernel. The worst thing that can happen is sending a corrupted TLS record, which is in any case not forbidden when using regular TCP sockets. Sockets other than TLS device offload are not affected by the new socket option. The actual status of zerocopy sendfile can be queried with sock_diag. Performance numbers in a single-core test with 24 HTTPS streams on nginx, under 100% CPU load: * non-zerocopy: 33.6 Gbit/s * zerocopy: 79.92 Gbit/s CPU: Intel(R) Xeon(R) Platinum 8380 CPU @ 2.30GHz Signed-off-by: Boris Pismenny <borisp@nvidia.com> Signed-off-by: Tariq Toukan <tariqt@nvidia.com> Signed-off-by: Maxim Mikityanskiy <maximmi@nvidia.com> Reviewed-by: Jakub Kicinski <kuba@kernel.org> Link: https://lore.kernel.org/r/20220518092731.1243494-1-maximmi@nvidia.com Signed-off-by: Paolo Abeni <pabeni@redhat.com> |
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| arch | ||
| block | ||
| certs | ||
| crypto | ||
| Documentation | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| ipc | ||
| kernel | ||
| lib | ||
| LICENSES | ||
| mm | ||
| net | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .cocciconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text 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.