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2022-06-03parisc: fix a crash with multicore schedulerMikulas Patocka1-15/+1
With the kernel 5.18, the system will hang on boot if it is compiled with CONFIG_SCHED_MC. The last printed message is "Brought up 1 node, 1 CPU". The crash happens in sd_init tl->mask (which is cpu_coregroup_mask) returns an empty mask. This happens because cpu_topology[0].core_sibling is empty. Consequently, sd_span is set to an empty mask sd_id = cpumask_first(sd_span) sets sd_id == NR_CPUS (because the mask is empty) sd->shared = *per_cpu_ptr(sdd->sds, sd_id); sets sd->shared to NULL because sd_id is out of range atomic_inc(&sd->shared->ref); crashes without printing anything We can fix it by calling reset_cpu_topology() from init_cpu_topology() - this will initialize the sibling masks on CPUs, so that they're not empty. This patch also removes the variable "dualcores_found", it is useless, because during boot, init_cpu_topology is called before store_cpu_topology. Thus, set_sched_topology(parisc_mc_topology) is never called. We don't need to call it at all because default_topology in kernel/sched/topology.c contains the same items as parisc_mc_topology. Note that we should not call store_cpu_topology() from init_per_cpu() because it is called too early in the kernel initialization process and it results in the message "Failure to register CPU0 device". Before this patch, store_cpu_topology() would exit immediatelly because cpuid_topo->core id was uninitialized and it was 0. Signed-off-by: Mikulas Patocka <mpatocka@redhat.com> Cc: stable@vger.kernel.org # v5.18 Signed-off-by: Helge Deller <deller@gmx.de>
2022-03-29parisc: Move store_cpu_topology() into text sectionHelge Deller1-2/+3
Signed-off-by: Helge Deller <deller@gmx.de>
2022-03-29parisc: Switch from GENERIC_CPU_DEVICES to GENERIC_ARCH_TOPOLOGYHelge Deller1-57/+15
Switch away from the own cpu topology code to common code which is used by ARM64 and RISCV. That will allow us to enable CPU hotplug later on. Signed-off-by: Helge Deller <deller@gmx.de>
2022-03-17parisc: Improve CPU socket and core bootup info textHelge Deller1-2/+2
Improve CPU bootup info text from: CPU1: thread -1, cpu 0, socket 1 to CPU1: cpu core 0 of socket 1 Signed-off-by: Helge Deller <deller@gmx.de>
2017-11-17parisc: Add CPU topology supportHelge Deller1-24/+129
Add topology support, including multi-core scheduler support on PA8800/PA8900 CPUs and enhanced output in /proc/cpuinfo, e.g. lscpu now reports on a single-socket, dual-core machine: Architecture: parisc64 CPU(s): 2 On-line CPU(s) list: 0,1 Thread(s) per core: 1 Core(s) per socket: 2 Socket(s): 1 CPU family: PA-RISC 2.0 Model name: PA8800 (Mako) Signed-off-by: Helge Deller <deller@gmx.de>
2009-01-05parisc: Replace NR_CPUS in parisc codeHelge Deller1-2/+2
parisc: Replace most arrays sized by NR_CPUS with percpu variables. Signed-off-by: Helge Deller <deller@gmx.de> Signed-off-by: Kyle McMartin <kyle@mcmartin.ca>
2007-02-17Replace remaining references to "driverfs" with "sysfs".Robert P. J. Day1-1/+1
Globally, s/driverfs/sysfs/g. Signed-off-by: Robert P. J. Day <rpjday@mindspring.com> Signed-off-by: Adrian Bunk <bunk@stusta.de>
2006-06-27[PATCH] node hotplug: register cpu: remove node structKAMEZAWA Hiroyuki1-2/+1
With Goto-san's patch, we can add new pgdat/node at runtime. I'm now considering node-hot-add with cpu + memory on ACPI. I found acpi container, which describes node, could evaluate cpu before memory. This means cpu-hot-add occurs before memory hot add. In most part, cpu-hot-add doesn't depend on node hot add. But register_cpu(), which creates symbolic link from node to cpu, requires that node should be onlined before register_cpu(). When a node is onlined, its pgdat should be there. This patch-set holds off creating symbolic link from node to cpu until node is onlined. This removes node arguments from register_cpu(). Now, register_cpu() requires 'struct node' as its argument. But the array of struct node is now unified in driver/base/node.c now (By Goto's node hotplug patch). We can get struct node in generic way. So, this argument is not necessary now. This patch also guarantees add cpu under node only when node is onlined. It is necessary for node-hot-add vs. cpu-hot-add patch following this. Moreover, register_cpu calculates cpu->node_id by cpu_to_node() without regard to its 'struct node *root' argument. This patch removes it. Also modify callers of register_cpu()/unregister_cpu, whose args are changed by register-cpu-remove-node-struct patch. [Brice.Goglin@ens-lyon.org: fix it] Signed-off-by: KAMEZAWA Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com> Cc: Yasunori Goto <y-goto@jp.fujitsu.com> Cc: Ashok Raj <ashok.raj@intel.com> Cc: Dave Hansen <haveblue@us.ibm.com> Signed-off-by: Brice Goglin <Brice.Goglin@ens-lyon.org> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-01-10[PARISC] Add __read_mostly section for pariscHelge Deller1-1/+2
Flag a whole bunch of things as __read_mostly on parisc. Also flag a few branches as unlikely() and cleanup a bit of code. Signed-off-by: Helge Deller <deller@parisc-linux.org> Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>
2005-04-16Linux-2.6.12-rc2Linus Torvalds1-0/+37
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!