mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-03 21:45:08 -04:00
ead1dec8ed
This reverts the two commits7afbeb6df2("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>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. 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.