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Eric Dumazet
84a7d6797e
tc_action_net_exit() got an rtnl exclusion in commita159d3c4b8("net_sched: acquire RTNL in tc_action_net_exit()") Since then, commit16af606739("net: sched: implement reference counted action release") made this RTNL exclusion obsolete for most cases. Only tcf_action_offload_del() might still require it. Move the rtnl locking into tcf_idrinfo_destroy() when an offload action is found. Most netns do not have actions, yet deleting them is adding a lot of pressure on RTNL, which is for many the most contended mutex in the kernel. We are moving to a per-netns 'rtnl', so tc_action_net_exit() will not be able to grab 'rtnl' a single time for a batch of netns. Before the patch: perf probe -a rtnl_lock perf record -e probe:rtnl_lock -a /bin/bash -c 'unshare -n "/bin/true"; sleep 1' [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.305 MB perf.data (25 samples) ] After the patch: perf record -e probe:rtnl_lock -a /bin/bash -c 'unshare -n "/bin/true"; sleep 1' [ perf record: Woken up 1 times to write data ] [ perf record: Captured and wrote 0.304 MB perf.data (9 samples) ] Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Vlad Buslov <vladbu@nvidia.com> Cc: Jiri Pirko <jiri@resnulli.us> Cc: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com> Link: https://patch.msgid.link/20250702071230.1892674-1-edumazet@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
``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.