3a2a1e9056
The driver uses mmap_sem for both pinned_vm accounting and get_user_pages(). Because rdma drivers might want to use gup_longterm() in the future we still need some sort of mmap_sem serialization (as opposed to removing it entirely by using gup_fast()). Now that pinned_vm is atomic the writer lock can therefore be converted to reader. This also fixes a bug that __qib_get_user_pages was not taking into account the current value of pinned_vm. Reviewed-by: Ira Weiny <ira.weiny@intel.com> Signed-off-by: Davidlohr Bueso <dbueso@suse.de> Signed-off-by: Jason Gunthorpe <jgg@mellanox.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 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.