3e401f7a2e
Calling arch_update_cpu_topology from a CPU hotplug state machine callback hits a deadlock because the function tries to get a read lock on cpu_hotplug_lock while the state machine still holds a write lock on it. Since all callers of arch_update_cpu_topology except rtasd already hold cpu_hotplug_lock, this patch changes the function to use stop_machine_cpuslocked and creates a separate function for rtasd which still tries to obtain the lock. Michael Bringmann investigated the bug and provided a detailed analysis of the deadlock on this previous RFC for an alternate solution: Signed-off-by: Thiago Jung Bauermann <bauerman@linux.vnet.ibm.com> Signed-off-by: Thomas Gleixner <tglx@linutronix.de> Acked-by: Michael Ellerman <mpe@ellerman.id.au> Cc: John Allen <jallen@linux.vnet.ibm.com> Cc: Michael Bringmann <mwb@linux.vnet.ibm.com> Cc: Nathan Fontenot <nfont@linux.vnet.ibm.com> Cc: linuxppc-dev@lists.ozlabs.org Link: http://lkml.kernel.org/r/1497996510-4032-1-git-send-email-bauerman@linux.vnet.ibm.com Link: https://patchwork.ozlabs.org/patch/771293/
104 lines
2.3 KiB
C
104 lines
2.3 KiB
C
#ifndef _ASM_POWERPC_TOPOLOGY_H
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#define _ASM_POWERPC_TOPOLOGY_H
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#ifdef __KERNEL__
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struct device;
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struct device_node;
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#ifdef CONFIG_NUMA
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/*
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* If zone_reclaim_mode is enabled, a RECLAIM_DISTANCE of 10 will mean that
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* all zones on all nodes will be eligible for zone_reclaim().
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*/
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#define RECLAIM_DISTANCE 10
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#include <asm/mmzone.h>
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#define parent_node(node) (node)
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#define cpumask_of_node(node) ((node) == -1 ? \
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cpu_all_mask : \
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node_to_cpumask_map[node])
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struct pci_bus;
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#ifdef CONFIG_PCI
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extern int pcibus_to_node(struct pci_bus *bus);
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#else
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static inline int pcibus_to_node(struct pci_bus *bus)
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{
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return -1;
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}
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#endif
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#define cpumask_of_pcibus(bus) (pcibus_to_node(bus) == -1 ? \
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cpu_all_mask : \
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cpumask_of_node(pcibus_to_node(bus)))
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extern int __node_distance(int, int);
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#define node_distance(a, b) __node_distance(a, b)
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extern void __init dump_numa_cpu_topology(void);
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extern int sysfs_add_device_to_node(struct device *dev, int nid);
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extern void sysfs_remove_device_from_node(struct device *dev, int nid);
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extern int numa_update_cpu_topology(bool cpus_locked);
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#else
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static inline void dump_numa_cpu_topology(void) {}
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static inline int sysfs_add_device_to_node(struct device *dev, int nid)
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{
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return 0;
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}
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static inline void sysfs_remove_device_from_node(struct device *dev,
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int nid)
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{
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}
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static inline int numa_update_cpu_topology(bool cpus_locked)
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{
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return 0;
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}
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#endif /* CONFIG_NUMA */
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#if defined(CONFIG_NUMA) && defined(CONFIG_PPC_SPLPAR)
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extern int start_topology_update(void);
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extern int stop_topology_update(void);
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extern int prrn_is_enabled(void);
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#else
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static inline int start_topology_update(void)
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{
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return 0;
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}
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static inline int stop_topology_update(void)
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{
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return 0;
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}
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static inline int prrn_is_enabled(void)
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{
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return 0;
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}
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#endif /* CONFIG_NUMA && CONFIG_PPC_SPLPAR */
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#include <asm-generic/topology.h>
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#ifdef CONFIG_SMP
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#include <asm/cputable.h>
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#ifdef CONFIG_PPC64
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#include <asm/smp.h>
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#define topology_physical_package_id(cpu) (cpu_to_chip_id(cpu))
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#define topology_sibling_cpumask(cpu) (per_cpu(cpu_sibling_map, cpu))
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#define topology_core_cpumask(cpu) (per_cpu(cpu_core_map, cpu))
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#define topology_core_id(cpu) (cpu_to_core_id(cpu))
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#endif
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#endif
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#endif /* __KERNEL__ */
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#endif /* _ASM_POWERPC_TOPOLOGY_H */
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