99f6b5fb5f
Currently rx page will be reused to receive future packet when the stack releases the previous skb quickly. If the old page can not be reused, a new page will be allocated and mapped, which comsumes a lot of cpu when IOMMU is in the strict mode, especially when the application and irq/NAPI happens to run on the same cpu. So allocate a new frag to memcpy the data to avoid the costly IOMMU unmapping/mapping operation, and add "frag_alloc_err" and "frag_alloc" stats in "ethtool -S ethX" cmd. The throughput improves above 50% when running single thread of iperf using TCP when IOMMU is in strict mode and iperf shares the same cpu with irq/NAPI(rx_copybreak = 2048 and mtu = 1500). Signed-off-by: Yunsheng Lin <linyunsheng@huawei.com> Signed-off-by: Guangbin Huang <huangguangbin2@huawei.com> Signed-off-by: David S. Miller <davem@davemloft.net> |
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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.