linux/arch
Heiko Carstens ead1dec8ed s390/ipl: revert Load Normal semantics for LPAR CCW-type re-IPL
This reverts the two commits

7afbeb6df2 ("s390/ipl: always use load normal for CCW-type re-IPL")
0f7451ff3a ("s390/ipl: use load normal for LPAR re-ipl")

The two commits did not take into account that behavior of standby
memory changes fundamentally if the re-IPL method is changed from
Load Clear to Load Normal.

In case of the old re-IPL clear method all memory that was initially
in standby state will be put into standby state again within the
re-IPL process. Or in other words: memory that was brought online
before a re-IPL will be offline again after a reboot.

Given that we use different re-IPL methods depending on the hypervisor
and CCW-type vs SCSI re-IPL it is not easy to tell in advance when and
why memory will stay online or will be offline after a re-IPL.
This does also have other side effects, since memory that is online
from the beginning will be in ZONE_NORMAL by default vs ZONE_MOVABLE
for memory that is offline.

Therefore, before the change, a user could online and offline memory
easily since standby memory was always in ZONE_NORMAL.  After the
change, and a re-IPL, this depended on which memory parts were online
before the re-IPL.

From a usability point of view the current behavior is more than
suboptimal. Therefore revert these changes until we have a better
solution and get back to a consistent behavior. The bad thing about
this is that the time required for a re-IPL will be significantly
increased for configurations with several 100GB or 1TB of memory.

Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com>
Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2017-06-12 16:26:01 +02:00
..
alpha Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
arc Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
arm arm64 2nd set of updates for 4.12: 2017-05-11 11:27:54 -07:00
arm64 Merge git://git.kernel.org/pub/scm/linux/kernel/git/davem/net 2017-05-15 15:50:49 -07:00
blackfin uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
c6x uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
cris MTD updates for 4.12-rc1: 2017-05-11 10:44:22 -07:00
frv Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
h8300 uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
hexagon uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
ia64 Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
m32r uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
m68k uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
metag Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
microblaze uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
mips Merge branch 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus 2017-05-12 09:56:30 -07:00
mn10300 uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
nios2 nios2 update for v4.12-rc1 2017-05-12 09:53:16 -07:00
openrisc uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
parisc uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
powerpc powerpc updates for 4.12 part 2 2017-05-12 10:04:09 -07:00
s390 s390/ipl: revert Load Normal semantics for LPAR CCW-type re-IPL 2017-06-12 16:26:01 +02:00
score uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
sh Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
sparc Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
tile arch/include: remove empty Kbuild files 2017-05-11 00:22:18 +09:00
um Merge branch 'for-linus-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2017-05-13 10:20:02 -07:00
unicore32 Kbuild UAPI header export updates for v4.12 2017-05-10 20:45:36 -07:00
x86 Merge branch 'for-linus-4.12-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/rw/uml 2017-05-13 10:20:02 -07:00
xtensa uapi: export all headers under uapi directories 2017-05-11 00:21:54 +09:00
.gitignore
Kconfig Merge branch 'core-rcu-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip 2017-05-10 10:30:46 -07:00