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885842d89a
Kirill Tkhai says:
====================
Replacing net_mutex with rw_semaphore
this is the third version of the patchset introducing net_sem
instead of net_mutex. The patchset adds net_sem in addition
to net_mutex and allows pernet_operations to be "async". This
flag means, the pernet_operations methods are safe to be
executed with any other pernet_operations (un)initializing
another net.
If there are only async pernet_operations in the system,
net_mutex is not used either for setup_net() or for cleanup_net().
The pernet_operations converted in this patchset allow
to create minimal .config to have network working, and
the changes improve the performance like you may see
below:
%for i in {1..10000}; do unshare -n bash -c exit; done
*before*
real 1m40,377s
user 0m9,672s
sys 0m19,928s
*after*
real 0m17,007s
user 0m5,311s
sys 0m11,779
(5.8 times faster)
In the future, when all pernet_operations become async,
we'll just remove this "async" field tree-wide.
All the new logic is concentrated in patches [1-5/32].
The rest of patches converts specific operations:
review, rationale of they can be converted, and setting
of async flag.
Kirill
v3: Improved patches descriptions. Added comment into [5/32].
Added [32/32] converting netlink_tap_net_ops (new pernet operations
introduced in 2018).
v2: Single patch -> patchset with rationale of every conversion
====================
Signed-off-by: David S. Miller <davem@davemloft.net>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.