summaryrefslogtreecommitdiffstats
path: root/arch/s390/numa
AgeCommit message (Collapse)AuthorFilesLines
2016-12-07s390/numa: pin all possible cpus to nodes earlyHeiko Carstens1-1/+22
It is required to have an early static cpu to node mapping. This patch pins all possible cpus to nodes for which no topology information is present. Since there is no interface available which would allow to tell where a non-present cpu would appear topology-wise, simply use a round robin algorithm. Right now this makes sure that the cpu_to_node() function will return the same value for a cpu during the life time of the system. Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-12-07s390/numa: establish cpu to node mapping earlyHeiko Carstens2-9/+16
Initialize the cpu topology and therefore also the cpu to node mapping much earlier. Fixes this warning and subsequent crashes when using the fake numa emulation mode on s390: WARNING: CPU: 0 PID: 1 at include/linux/cpumask.h:121 select_task_rq+0xe6/0x1a8 CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.6.0-rc6-00001-ge9d867a67fd0-dirty #28 task: 00000001dd270008 ti: 00000001eccb4000 task.ti: 00000001eccb4000 Krnl PSW : 0404c00180000000 0000000000176c56 (select_task_rq+0xe6/0x1a8) R:0 T:1 IO:0 EX:0 Key:0 M:1 W:0 P:0 AS:3 CC:0 PM:0 RI:0 EA:3 Call Trace: ([<0000000000176c30>] select_task_rq+0xc0/0x1a8) ([<0000000000177d64>] try_to_wake_up+0x2e4/0x478) ([<000000000015d46c>] create_worker+0x174/0x1c0) ([<0000000000161a98>] alloc_unbound_pwq+0x360/0x438) ([<0000000000162550>] apply_wqattrs_prepare+0x200/0x2a0) ([<000000000016266a>] apply_workqueue_attrs_locked+0x7a/0xb0) ([<0000000000162af0>] apply_workqueue_attrs+0x50/0x78) ([<000000000016441c>] __alloc_workqueue_key+0x304/0x520) ([<0000000000ee3706>] default_bdi_init+0x3e/0x70) ([<0000000000100270>] do_one_initcall+0x140/0x1d8) ([<0000000000ec9da8>] kernel_init_freeable+0x220/0x2d8) ([<0000000000984a7a>] kernel_init+0x2a/0x150) ([<00000000009913fa>] kernel_thread_starter+0x6/0xc) ([<00000000009913f4>] kernel_thread_starter+0x0/0xc) Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-12-07s390/topology: use cpu_topology array instead of per cpu variableHeiko Carstens1-2/+2
CPU topology information like cpu to node mapping must be setup in setup_arch already. Topology information is currently made available with a per cpu variable; this however will not work when the initialization will be moved to setup_arch, since the generic percpu setup will be done much later. Therefore convert back to a cpu_topology array. Reviewed-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-12-07s390/numa: always use logical cpu and core idsHeiko Carstens1-1/+1
The toptree algorithm uses the physical core ids to create a mapping between cores and nodes (to_node_id array within emu_cores structure). The core ids are used as an index into an array which size depends on CONFIG_NR_CPUS. If the physical core ids are larger, this will result in out-of-bounds write accesses. Generate logical core ids instead to avoid this. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-07-31s390/numa: only set possible nodes within node_possible_mapHeiko Carstens2-1/+11
Make sure that only those nodes appear in the node_possible_map that may actually be used. Usually that means that the node online and possible maps are identical. For mode "plain" we only have one node, for mode "emu" we have "emu_nodes" nodes. Before this the possible map included (with default config) 16 nodes while usually only one was used. That made a couple of loops that iterated over all possible nodes do more work than necessary. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-06-13s390/topology: add drawer scheduling domain levelHeiko Carstens1-5/+20
The z13 machine added a fourth level to the cpu topology information. The new top level is called drawer. A drawer contains two books, which used to be the top level. Adding this additional scheduling domain did show performance improvements for some workloads of up to 8%, while there don't seem to be any workloads impacted in a negative way. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Peter Zijlstra (Intel) <peterz@infradead.org> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-01-26s390/numa: move numa_init_late() from device to arch_initcallMichael Holzheu1-1/+1
Commit 3e89e1c5ea ("hugetlb: make mm and fs code explicitly non-modular") moves hugetlb_init() from module_init to subsys_initcall. The hugetlb_init()->hugetlb_register_node() code accesses "node->dev.kobj" which is initialized in numa_init_late(). Since numa_init_late() is a device_initcall which is called *after* subsys_initcall the above mentioned patch breaks NUMA on s390. So fix this and move numa_init_late() to arch_initcall. Fixes: 3e89e1c5ea ("hugetlb: make mm and fs code explicitly non-modular") 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>
2016-01-19s390: remove superfluous memblock_alloc() return value checksHeiko Carstens1-2/+0
memblock_alloc() and memblock_alloc_base() will panic on their own if they can't find free memory. Therefore remove some pointless checks. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2016-01-19s390/numa: allocate memory with correct alignmentHeiko Carstens1-1/+1
Allocating memory with a requested minimum alignment of 1 is wrong since pg_data_t contains a spinlock which requires an alignment of 4 bytes. Therefore fix this and ask for an alignment of 8 bytes like it is guarenteed for all kmalloc requests. Signed-off-by: Heiko Carstens <heiko.carstens@de.ibm.com> Acked-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-10-14s390/numa: write kernel message when emu_size has been increasedMichael Holzheu1-2/+8
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-09-23s390/numa: use correct type for node_to_cpumask_mapMartin Schwidefsky2-4/+4
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>
2015-08-07s390/numa: make core to node mapping data dynamicMichael Holzheu1-27/+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>
2015-08-07s390/topology: remove topology lockMichael Holzheu1-1/+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>
2015-08-04s390/numa: add emulation supportMichael Holzheu4-0/+517
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>
2015-08-03s390/numa: add topology tree infrastructurePhilipp Hachtmann3-0/+403
NUMA emulation needs proper means to mangle the book/mc/core topology of the machine. The topology tree (toptree) consistently maintains cpu masks for the root, each node, and all leaves of the tree while the user may use the toptree functions to rearrange the tree in various ways. This patch contains several changes from Michael Holzheu. Signed-off-by: Philipp Hachtmann <phacht@linux.vnet.ibm.com> Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
2015-08-03s390/numa: add core infrastructurePhilipp Hachtmann3-0/+204
Enable core NUMA support for s390 and add one simple default mode "plain" that creates one single NUMA node. This patch contains several changes from Michael Holzheu. Signed-off-by: Philipp Hachtmann <phacht@linux.vnet.ibm.com> Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com> Signed-off-by: Martin Schwidefsky <schwidefsky@de.ibm.com>
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-19 04:40:31 +0000