mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-04-29 02:19:54 -04:00
603fd64dfa
Radix vmemmap mapping can map things correctly at the PMD level or PTE level based on different device boundary checks. Hence we skip the restrictions w.r.t vmemmap size to be multiple of PMD_SIZE. This also makes the feature widely useful because to use PMD_SIZE vmemmap area we require a memory block size of 2GiB We can also use MHP_RESERVE_PAGES_MEMMAP_ON_MEMORY to that the feature can work with a memory block size of 256MB. Using altmap.reserve feature to align things correctly at pageblock granularity. We can end up losing some pages in memory with this. For ex: with a 256MiB memory block size, we require 4 pages to map vmemmap pages, In order to align things correctly we end up adding a reserve of 28 pages. ie, for every 4096 pages 28 pages get reserved. Link: https://lkml.kernel.org/r/20230808091501.287660-6-aneesh.kumar@linux.ibm.com Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com> Reviewed-by: David Hildenbrand <david@redhat.com> Cc: Christophe Leroy <christophe.leroy@csgroup.eu> Cc: Michael Ellerman <mpe@ellerman.id.au> Cc: Michal Hocko <mhocko@suse.com> Cc: Nicholas Piggin <npiggin@gmail.com> Cc: Oscar Salvador <osalvador@suse.de> Cc: Vishal Verma <vishal.l.verma@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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.