f05f62d042
I can't come up with a satisfying reason why we still need the memory
segment list. We used to represent in the list:
- boot memory
- standby memory added via add_memory()
- loaded dcss segments
When loading/unloading dcss segments, we already track them in a
separate list and check for overlaps
(arch/s390/mm/extmem.c:segment_overlaps_others()) when loading segments.
The overlap check was introduced for some segments in
commit b2300b9efe1b ("[S390] dcssblk: add >2G DCSSs support and stacked
contiguous DCSSs support.")
and was extended to cover all dcss segments in
commit ca57114609d1 ("s390/extmem: remove code for 31 bit addressing
mode").
Although I doubt that overlaps with boot memory and standby memory
are relevant, let's reshuffle the checks in load_segment() to request
the resource first. This will bail out in case we have overlaps with
other resources (esp. boot memory and standby memory). The order
is now different compared to segment_unload() and segment_unload(), but
that should not matter.
This smells like a leftover from ancient times, let's get rid of it. We
can now convert vmem_remove_mapping() into a void function - everybody
ignored the return value already.
Cc: Vasily Gorbik <gor@linux.ibm.com>
Cc: Christian Borntraeger <borntraeger@de.ibm.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Hildenbrand <david@redhat.com>
Message-Id: <20200625150029.45019-1-david@redhat.com>
Reviewed-by: Gerald Schaefer <gerald.schaefer@de.ibm.com>
Tested-by: Gerald Schaefer <gerald.schaefer@de.ibm.com> [DCSS]
Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.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.