Jason, Just pulled for-next and now hit the following warning. Register user space memory is not longer working. I am trying to debug this but if you have any idea where to look let me know. Bob [ 209.562096] WARNING: CPU: 12 PID: 5343 at lib/scatterlist.c:438 __sg_alloc_table_from_pages+0x21/0x440 [ 209.562097] Modules linked in: rdma_rxe ip6_udp_tunnel udp_tunnel rfcomm xt_CHECKSUM xt_MASQUERADE xt_conntrack ipt_REJECT nf_reject_ipv4 xt_tcpudp ip6table_mangle ip6table_nat iptable_mangle iptable_nat nf_nat nf_conntrack nf_defrag_ipv6 nf_defrag_ipv4 libcrc32c nf_tables nfnetlink ip6table_filter ip6_tables iptable_filter bpfilter bridge stp llc cmac algif_hash algif_skcipher af_alg bnep binfmt_misc iwlmvm btusb btrtl btbcm input_leds mac80211 btintel bluetooth libarc4 iwlwifi ib_uverbs snd_hda_codec_realtek snd_hda_codec_generic ecdh_generic ib_core cfg80211 igb ledtrig_audio ecc snd_hda_codec_hdmi hid_generic snd_hda_intel snd_intel_dspcfg dca snd_hda_codec snd_hda_core usbhid snd_hwdep nls_iso8859_1 amdgpu mlx5_core edac_mce_amd hid snd_pcm kvm_amd kvm iommu_v2 snd_seq_midi snd_seq_midi_event gpu_sched ttm wmi_bmof mxm_wmi snd_rawmidi drm_kms_helper snd_seq tls crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_intel snd_seq_device crypto_simd snd_timer mlxfw cryptd cec [ 209.562135] glue_helper ccp snd rapl pci_hyperv_intf i2c_algo_bit ahci i2c_piix4 efi_pstore soundcore fb_sys_fops libahci syscopyarea k10temp sysfillrect sysimgblt wmi drm sunrpc sch_fq_codel parport_pc ppdev lp parport ip_tables x_tables autofs4 nvme nvme_core mac_hid [ 209.562149] CPU: 12 PID: 5343 Comm: python3 Not tainted 5.9.0-rc8+ #20 [ 209.562150] Hardware name: Gigabyte Technology Co., Ltd. X570 AORUS PRO WIFI/X570 AORUS PRO WIFI, BIOS F11 12/06/2019 [ 209.562153] RIP: 0010:__sg_alloc_table_from_pages+0x21/0x440 [ 209.562155] Code: c3 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 41 56 41 55 41 89 d5 41 54 53 48 83 ec 48 48 89 7d a0 48 8b 55 10 45 85 c9 75 1b <0f> 0b 49 c7 c2 ea ff ff ff 48 83 c4 48 4c 89 d0 5b 41 5c 41 5d 41 [ 209.562156] RSP: 0018:ffffb86648b879a8 EFLAGS: 00010206 [ 209.562157] RAX: 0000000000001000 RBX: 000000000238c000 RCX: 0000000000000000 [ 209.562158] RDX: 0000000000000000 RSI: ffff8ab0c2667000 RDI: ffff8ab0d7b0c1d0 [ 209.562159] RBP: ffffb86648b87a18 R08: 0000000000001000 R09: 00000000ffffffff [ 209.562160] R10: 0000000000000022 R11: 0000000000000001 R12: ffff8ab0faace000 [ 209.562161] R13: 0000000000000001 R14: 00000000ffffffff R15: ffff8ab0c2667000 [ 209.562162] FS: 00007f1846f00740(0000) GS:ffff8ab0feb00000(0000) knlGS:0000000000000000 [ 209.562163] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 209.562164] CR2: 00000000022c5098 CR3: 000000074ab48000 CR4: 0000000000350ee0 [ 209.562165] Call Trace: [ 209.562176] ib_umem_get+0x1b1/0x390 [ib_uverbs] [ 209.562182] rxe_mem_init_user+0x48/0x1e0 [rdma_rxe] [ 209.562187] rxe_reg_user_mr+0x96/0x160 [rdma_rxe] [ 209.562193] ib_uverbs_reg_mr+0x141/0x270 [ib_uverbs] [ 209.562199] ib_uverbs_handler_UVERBS_METHOD_INVOKE_WRITE+0xd2/0x140 [ib_uverbs] [ 209.562202] ? __check_object_size+0x4d/0x150 [ 209.562207] ib_uverbs_cmd_verbs+0xb37/0xc70 [ib_uverbs]
