forked from mirrors/linux
		
	On pseries systems, performing a partition migration can result in altering the nodes a CPU is assigned to on the destination system. For exampl, pre-migration on the source system CPUs are in node 1 and 3, post-migration on the destination system CPUs are in nodes 2 and 3. Handling the node change for a CPU can cause corruption in the slab cache if we hit a timing where a CPUs node is changed while cache_reap() is invoked. The corruption occurs because the slab cache code appears to rely on the CPU and slab cache pages being on the same node. The current dynamic updating of a CPUs node done in arch/powerpc/mm/numa.c does not prevent us from hitting this scenario. Changing the device tree property update notification handler that recognizes an affinity change for a CPU to do a full DLPAR remove and add of the CPU instead of dynamically changing its node resolves this issue. Signed-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com> Signed-off-by: Michael W. Bringmann <mwb@linux.vnet.ibm.com> Tested-by: Michael W. Bringmann <mwb@linux.vnet.ibm.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
		
			
				
	
	
		
			141 lines
		
	
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
			
		
		
	
	
			141 lines
		
	
	
	
		
			3.2 KiB
		
	
	
	
		
			C
		
	
	
	
	
	
/* SPDX-License-Identifier: GPL-2.0 */
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#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 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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static inline void update_numa_cpu_lookup_table(unsigned int cpu, int node)
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{
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	numa_cpu_lookup_table[cpu] = node;
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}
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static inline int early_cpu_to_node(int cpu)
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{
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	int nid;
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	nid = numa_cpu_lookup_table[cpu];
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	/*
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	 * Fall back to node 0 if nid is unset (it should be, except bugs).
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	 * This allows callers to safely do NODE_DATA(early_cpu_to_node(cpu)).
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	 */
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	return (nid < 0) ? 0 : nid;
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}
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#else
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static inline int early_cpu_to_node(int cpu) { return 0; }
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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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static inline void update_numa_cpu_lookup_table(unsigned int cpu, int node) {}
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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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extern int find_and_online_cpu_nid(int cpu);
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extern int timed_topology_update(int nsecs);
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extern void __init shared_proc_topology_init(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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static inline int find_and_online_cpu_nid(int cpu)
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{
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	return 0;
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}
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static inline int timed_topology_update(int nsecs)
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{
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	return 0;
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}
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#ifdef CONFIG_SMP
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static inline void shared_proc_topology_init(void) {}
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#endif
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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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int dlpar_cpu_readd(int 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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