{"push_id":2925386572,"size":1,"distinct_size":1,"ref":"refs/heads/_v2__powerpc_pseries_Track_LMB_nid_instead_of_using_device_tree_mbox_next","head":"d381d3d5d19b0d3c5733d2491eb735daa0a936ee","before":"e72c9bbea0858b2b61ab17ca92740f5c2b47c0b8","commits":[{"sha":"d381d3d5d19b0d3c5733d2491eb735daa0a936ee","author":{"name":"Nathan Fontenot","email":"4b7bfe500077bf77c5456931a34b0b70e36e0bc6@linux.vnet.ibm.com"},"message":"powerpc/pseries: Track LMB nid instead of using device tree\n\nWhen removing memory we need to remove the memory from the node\nit was added to instead of looking up the node it should be in\nin the device tree.\n\nDuring testing we have seen scenarios where the affinity for a\nLMB changes due to a partition migration or PRRN event. In these\ncases the node the LMB exists in may not match the node the device\ntree indicates it belongs in. This can lead to a system crash\nwhen trying to DLPAR remove the LMB after a migration or PRRN\nevent. The current code looks up the node in the device tree to\nremove the LMB from, the crash occurs when we try to offline this\nnode and it does not have any data, i.e. node_data[nid] == NULL.\n\n36:mon> e\ncpu 0x36: Vector: 300 (Data Access) at [c0000001828b7810]\n    pc: c00000000036d08c: try_offline_node+0x2c/0x1b0\n    lr: c0000000003a14ec: remove_memory+0xbc/0x110\n    sp: c0000001828b7a90\n   msr: 800000000280b033\n   dar: 9a28\n dsisr: 40000000\n  current = 0xc0000006329c4c80\n  paca    = 0xc000000007a55200   softe: 0        irq_happened: 0x01\n    pid   = 76926, comm = kworker/u320:3\n\n36:mon> t\n[link register   ] c0000000003a14ec remove_memory+0xbc/0x110\n[c0000001828b7a90] c00000000006a1cc arch_remove_memory+0x9c/0xd0 (unreliable)\n[c0000001828b7ad0] c0000000003a14e0 remove_memory+0xb0/0x110\n[c0000001828b7b20] c0000000000c7db4 dlpar_remove_lmb+0x94/0x160\n[c0000001828b7b60] c0000000000c8ef8 dlpar_memory+0x7e8/0xd10\n[c0000001828b7bf0] c0000000000bf828 handle_dlpar_errorlog+0xf8/0x160\n[c0000001828b7c60] c0000000000bf8cc pseries_hp_work_fn+0x3c/0xa0\n[c0000001828b7c90] c000000000128cd8 process_one_work+0x298/0x5a0\n[c0000001828b7d20] c000000000129068 worker_thread+0x88/0x620\n[c0000001828b7dc0] c00000000013223c kthread+0x1ac/0x1c0\n[c0000001828b7e30] c00000000000b45c ret_from_kernel_thread+0x5c/0x80\n\nTo resolve this we need to track the node a LMB belongs to when\nit is added to the system so we can remove it from that node instead\nof the node that the device tree indicates it should belong to.\n\nSigned-off-by: Nathan Fontenot <nfont@linux.vnet.ibm.com>","distinct":true,"url":"https://api.github.com/repos/ruscur/linux/commits/d381d3d5d19b0d3c5733d2491eb735daa0a936ee"}]}
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