34c604d275
The kernel page table caches are tied to init_mm, so there is no more need for them after userspace is finished. destroy_context() gets called when we drop the last reference for an mm, which can be much later than the task exit due to other lazy mm references to it. We can free the page table cache pages on task exit because they only cache the userspace page tables and kernel threads should not access user space addresses. The mapping for kernel threads itself is maintained in init_mm and page table cache for that is attached to init_mm. Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Reviewed-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> [mpe: Merge change log additions from Aneesh] Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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.
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.