78076bb64a
We recently changed this from a single list to an rbtree, but for some real life workloads, the rbtree slows down the submission/insertion case enough so that it's the top cycle consumer on the io_uring side. In testing, using a hash table is a more well rounded compromise. It is fast for insertion, and as long as it's sized appropriately, it works well for the cancellation case as well. Running TAO with a lot of network sockets, this removes io_poll_req_insert() from spending 2% of the CPU cycles. Reported-by: Dan Melnic <dmm@fb.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
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.