689883de94
Once the THREADED napi is disabled, the napi kthread should also be stopped. Keeping the kthread intact after disabling THREADED napi makes the PID of this kthread show up in the output of netlink 'napi-get' and ps -ef output. The is discussed in the patch below: https://lore.kernel.org/all/20250502191548.559cc416@kernel.org NAPI kthread should stop only if, - There are no pending napi poll scheduled for this thread. - There are no new napi poll scheduled for this thread while it has stopped. - The ____napi_schedule can correctly fallback to the softirq for napi polling. Since napi_schedule_prep provides mutual exclusion over STATE_SCHED bit, it is safe to unset the STATE_THREADED when SCHED_THREADED is set or the SCHED bit is not set. SCHED_THREADED being set means that SCHED is already set and the kthread owns this napi. To disable threaded napi, unset STATE_THREADED bit safely if SCHED_THREADED is set or SCHED is unset. Once STATE_THREADED is unset safely then wait for the kthread to unset the SCHED_THREADED bit so it safe to stop the kthread. Add a new test in nl_netdev to verify this behaviour. Tested: ./tools/testing/selftests/net/nl_netdev.py TAP version 13 1..6 ok 1 nl_netdev.empty_check ok 2 nl_netdev.lo_check ok 3 nl_netdev.page_pool_check ok 4 nl_netdev.napi_list_check ok 5 nl_netdev.dev_set_threaded ok 6 nl_netdev.nsim_rxq_reset_down # Totals: pass:6 fail:0 xfail:0 xpass:0 skip:0 error:0 Ran neper for 300 seconds and did enable/disable of thread napi in a loop continuously. Signed-off-by: Samiullah Khawaja <skhawaja@google.com> Link: https://patch.msgid.link/20250609173015.3851695-1-skhawaja@google.com Signed-off-by: Jakub Kicinski <kuba@kernel.org> |
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| Documentation | ||
| LICENSES | ||
| arch | ||
| block | ||
| certs | ||
| crypto | ||
| drivers | ||
| fs | ||
| include | ||
| init | ||
| io_uring | ||
| ipc | ||
| kernel | ||
| lib | ||
| mm | ||
| net | ||
| rust | ||
| samples | ||
| scripts | ||
| security | ||
| sound | ||
| tools | ||
| usr | ||
| virt | ||
| .clang-format | ||
| .clippy.toml | ||
| .cocciconfig | ||
| .editorconfig | ||
| .get_maintainer.ignore | ||
| .gitattributes | ||
| .gitignore | ||
| .mailmap | ||
| .pylintrc | ||
| .rustfmt.toml | ||
| COPYING | ||
| CREDITS | ||
| Kbuild | ||
| Kconfig | ||
| MAINTAINERS | ||
| Makefile | ||
| README | ||
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 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.