summaryrefslogtreecommitdiffstats
path: root/arch/s390/numa/mode_emu.c
Commit message (Collapse)AuthorAgeFilesLines
* s390/numa: write kernel message when emu_size has been increasedMichael Holzheu2015-10-141-2/+8
| | | | | Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/numa: use correct type for node_to_cpumask_mapMartin Schwidefsky2015-09-231-2/+2
| | | | | | | With CONFIG_CPUMASK_OFFSTACK=y cpumask_var_t is a pointer to a CPU mask. Replace the incorrect type for node_to_cpumask_map with cpumask_t. Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/numa: make core to node mapping data dynamicMichael Holzheu2015-08-071-27/+41
| | | | | | | | | | | The core to node mapping data consumes about 2 KB bss data. To save memory for the non-NUMA case, make the data dynamic. In addition change the "core_to_node" array from "int" to "s32" which saves 1 KB also for the NUMA case. Suggested-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/topology: remove topology lockMichael Holzheu2015-08-071-1/+6
| | | | | | | | | Since we are already protected by the "sched_domains_mutex" lock, we can safely remove the topology lock. Reviewed-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
* s390/numa: add emulation supportMichael Holzheu2015-08-041-0/+511
NUMA emulation (aka fake NUMA) distributes the available memory to nodes without using real topology information about the physical memory of the machine. Splitting the system memory into nodes replicates the memory management structures for each node. Particularly each node has its own "mm locks" and its own "kswapd" task. For large systems, under certain conditions, this results in improved system performance and/or latency based on reduced pressure on the mm locks and the kswapd tasks. NUMA emulation distributes CPUs to nodes while respecting the original machine topology information. This is done by trying to avoid to separate CPUs which reside on the same book or even on the same MC. Because the current Linux scheduler code requires a stable cpu to node mapping, cores are pinned to nodes when the first CPU thread is set online. This patch is based on the initial implementation from Philipp Hachtmann. Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
OpenPOWER on IntegriCloud