> From: Chuck Lever [mailto:chuck.lever@xxxxxxxxxx] > Sent: Tuesday, March 13, 2018 5:27 PM > >> Hi Chuck, the PD that is not freed here by rpcrdma is freed if we issue a > umount. > >> > >> Mount: this is the creation of the pd: > >> [ 1162.401116] ? rpcrdma_create_id+0x20b/0x270 [rpcrdma] [ > >> 1162.401124] rpcrdma_ia_open+0x40/0xe0 [rpcrdma] [ 1162.401132] > >> xprt_setup_rdma+0x110/0x3a0 [rpcrdma] [ 1162.401147] > >> xprt_create_transport+0x7d/0x210 [sunrpc] [ 1162.401161] > >> rpc_create+0xc5/0x1c0 [sunrpc] > >> > >> Umount: > >> [ 1011.602701] qedr_dealloc_pd+0x18/0x90 [qedr] [ 1011.602709] > >> ib_dealloc_pd+0x45/0x80 [ib_core] [ 1011.602716] > >> rpcrdma_ia_close+0x57/0x70 [rpcrdma] [ 1011.602719] > >> xprt_rdma_destroy+0x4d/0xb0 [rpcrdma] > > > > That is by design. Whether that design is correct or not remains to be seen. > > > > It wasn't clear to me that deallocating the PD on device removal was > > necessary. At least the ID has to stay around until the core removes it. > > > > No-one complained about the missing ib_dealloc_pd during review. > > > > And, since I was able to unload the device driver with the current > > design, I thought my assumption about leaving the PD was correct. > > Under normal circumstances, with the current kernel, this is still the > > case, and I don't see restracker warnings unless the transport is in some > pathological state. > > > > > >> Why not call rpcrdma_ia_close from rpcrdma_ia_remove > > > > rpcrdma_ia_close also destroys the ID. > > > > I suppose that since the actual work of tearing things down is done in > > another thread, it would be safe for xprtrdma to destroy the ID > > itself, rather than having the core do it once the upcall returns. In > > at least one of the prototypes, the tear-down was done in the upcall > > thread, so the ID had to be left alone. That aspect of the design has > > stayed in the code--perhaps unnecessarily? > > I take that back: the core is holding a mutex during the upcall, so calling > rdma_destroy_id will likely deadlock no matter what thread is calling. > > The most back-portable approach might be to dealloc the PD in > rpcrdma_ia_remove. rpcrdma_ia_close and rpcrdma_ia_remove can then be > de-duplicated in a subsequent patch. > > 447 ib_free_cq(ep->rep_attr.recv_cq); > 448 ib_free_cq(ep->rep_attr.send_cq); > +++ ib_dealloc_pd(ia->ri_pd); > 449 Hi Chuck, thanks for the suggestion. However, this lead to another issue A warning in dealloc_pd since pd->use_cnt isn't zero ( I guess decremented by rdma-destroy-id)? [ 126.768366] ib_srpt srpt_remove_one(qedr0): nothing to do. [ 126.768938] rpcrdma: removing device qedr0 for 192.168.10.57:20049 [ 126.769240] WARNING: CPU: 6 PID: 550 at drivers/infiniband/core/verbs.c:317 ib_dealloc_pd+0x6b/0x80 [ib_core] What is supposed to lead to destroying the rdma-cm- ID at any stage? I understand the race you're describing, But not clear on what's supposed to indicate to rdma-cm and when that this id should be freed? I know that all user context rdma-cm-id are freed when an application exists, but thought ULPs are responsible For freeing their resources. Thanks, Michal > > Fixes: bebd03186 ("xprtrdma: Support unplugging an HCA from under an NFS > mount") > > Can you give that a try? > > > > Advice on this is welcome! > > > > > >> Thanks, > >> Michal > >> > >>> > >>>> > >>>> > >>>>>>>> Thanks, > >>>>>>>> Michal > >>>>>>>> > >>>>>>>> GAD17990 login: [ 300.480137] ib_srpt srpt_remove_one(qedr0): > >>>>>>>> nothing > >>>>>> to do. > >>>>>>>> [ 300.515527] ib_srpt srpt_remove_one(qedr1): nothing to do. > >>>>>>>> [ 300.542182] rpcrdma: removing device qedr1 for > >>>>>>>> 192.168.110.146:20049 [ 300.573789] WARNING: CPU: 12 PID: 3545 > >>>>>>>> at > >>>>>>>> drivers/infiniband/core/restrack.c:20 > >>>>>>>> rdma_restrack_clean+0x25/0x30 [ib_core] [ 300.625985] Modules > >>>>>>>> linked in: rpcsec_gss_krb5 nfsv4 dns_resolver nfs fscache > >>>>>>>> rpcrdma ib_isert iscsi_target_mod ib_iser libiscsi > >>>>>>>> scsi_transport_iscsi ib_srpt target_core_mod ib_srp > >>>>>>>> scsi_transport_srp ib_ipoib rdma_ucm ib_ucm ib_uverbs ib_umad > >>>>>>>> rdma_cm ib_cm iw_cm 8021q > >>> garp > >>>>>>>> mrp qedr(-) ib_core xt_CHECKSUM iptable_mangle > >>> ipt_MASQUERADE > >>>>>>>> nf_nat_masquerade_ipv4 > >>>> iptable_nat > >>>>>>>> nf_nat_ipv4 nf_nat nf_conntrack_ipv4 nf_defrag_ipv4 > >>>>>>>> xt_conntrack nf_conntrack ipt_REJECT nf_reject_ipv4 tun bridge > >>>>>>>> stp llc ebtable_filter ebtables fuse ip6table_filter ip6_tables > >>>>>>>> iptable_filter dm_mirror dm_region_hash dm_log dm_mod vfat > fat > >>>>>>>> dax intel_rapl sb_edac x86_pkg_temp_thermal intel_powerclamp > >>>> coretemp > >>>>>>>> kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul > >>>>>>>> ghash_clmulni_intel pcbc aesni_intel crypto_simd glue_helper > >>>>>>>> cryptd ipmi_si [ 300.972993] iTCO_wdt ipmi_devintf sg pcspkr > >>>>>> iTCO_vendor_support hpwdt hpilo lpc_ich ipmi_msghandler > >>> pcc_cpufreq > >>>>>> ioatdma i2c_i801 mfd_core wmi shpchp dca acpi_power_meter > >>>>>> i2c_core nfsd auth_rpcgss nfs_acl lockd grace sunrpc ip_tables > >>>>>> xfs libcrc32c sd_mod qede qed crc32c_intel tg3 hpsa > >>>>>> scsi_transport_sas crc8 [ > >>>> 301.109036] CPU: 12 PID: > >>>>>> 3545 Comm: rmmod Not tainted 4.16.0-rc1 #1 [ 301.139518] > >>>>>> Hardware > >>>> name: > >>>>>> HP ProLiant DL380 Gen9/ProLiant DL380 Gen9, BIOS P89 02/17/2017 [ > >>>>>> 301.180411] RIP: 0010:rdma_restrack_clean+0x25/0x30 [ib_core] [ > >>>>>> 301.208350] RSP: 0018:ffffb1820478fe88 EFLAGS: 00010286 [ > >>>>>> 301.233241] > >>>>>> RAX: 0000000000000000 RBX: ffffa099ed1b4070 RCX: > ffffdf02a193c800 > >>>>>> [ 301.268001] RDX: ffffa095ed12d7a0 RSI: 0000000000025900 RDI: > >>>>>> ffffa099ed1b47d0 [ 301.302530] RBP: ffffa099ed1b4070 R08: > >>>>>> ffffa095de9dd000 R09: 0000000180080007 [ 301.337245] R10: > >>>>>> 0000000000000001 R11: ffffa095de9dd000 R12: ffffa099ed1b4000 [ > >>>>>> 301.372151] R13: ffffa099ed1b405c R14: 0000000000e231c0 R15: > >>>>>> 0000000000e23010 [ 301.407384] FS: 00007f2b0c854740(0000) > >>>>>> GS:ffffa099ff700000(0000) knlGS:0000000000000000 [ 301.447026] > CS: > >>>>>> 0010 > >>>>>> DS: 0000 ES: 0000 CR0: 0000000080050033 [ 301.475409] CR2: > >>>>>> 0000000000e2caf8 CR3: 0000000865c0d006 CR4: 00000000001606e0 [ > >>>>>> 301.510892] Call Trace: > >>>>>>>> [ 301.522715] ib_unregister_device+0xf5/0x190 [ib_core] [ > >>>>>>>> 301.547966] qedr_remove+0x37/0x60 [qedr] [ 301.568393] > >>>>>>>> qede_rdma_unregister_driver+0x4b/0x90 [qede] [ 301.594980] > >>>>>>>> SyS_delete_module+0x168/0x240 [ 301.615057] > >>>>>>>> do_syscall_64+0x6f/0x1a0 [ 301.633588] > >>>>>>>> entry_SYSCALL_64_after_hwframe+0x21/0x86 > >>>>>>>> [ 301.658657] RIP: 0033:0x7f2b0bd33707 [ 301.676005] RSP: > >>>>>>>> 002b:00007ffdefa29d98 EFLAGS: 00000202 ORIG_RAX: > >>>> 00000000000000b0 > >>>>>> [ > >>>>>>>> 301.713324] RAX: ffffffffffffffda RBX: 0000000000e231c0 RCX: > >>>>>>>> 00007f2b0bd33707 [ 301.748186] RDX: 00007f2b0bda3a80 RSI: > >>>>>>>> 0000000000000800 RDI: 0000000000e23228 [ 301.782960] RBP: > >>>>>>>> 0000000000000000 R08: 00007f2b0bff8060 R09: 00007f2b0bda3a80 > [ > >>>>>>>> 301.818142] R10: 00007ffdefa29b20 R11: 0000000000000202 R12: > >>>>>>>> 00007ffdefa2b70d [ 301.853290] R13: 0000000000000000 R14: > >>>>>>>> 0000000000e231c0 R15: 0000000000e23010 [ 301.888138] Code: 84 > >>>>>>>> 00 > >>>>>>>> 00 > >>>>>>>> 00 00 00 0f 1f 44 00 00 48 83 c7 28 31 c0 eb 0c 48 83 c0 08 48 > >>>>>>>> 3d > >>>>>>>> 00 > >>>>>>>> 08 00 00 74 0f 48 8d 14 07 48 8b 12 48 85 d2 74 e8 <0f> ff c3 > >>>>>>>> f3 > >>>>>>>> c3 > >>>>>>>> 66 0f 1f 44 00 00 0f 1f 44 00 00 53 48 8b 47 28 [ 301.981140] > >>>>>>>> ---[ end trace 28dec8f15205789a ]--- > >>>>>>> > >>>>>>> -- > >>>>>>> Chuck Lever > >>>>>>> > >>>>>>> > >>>>>>> > >>>>> -- > >>>>> To unsubscribe from this list: send the line "unsubscribe linux-rdma" > >>>>> in the body of a message to majordomo@xxxxxxxxxxxxxxx More > >>>> majordomo > >>>>> info at http://vger.kernel.org/majordomo-info.html > >>>> > >>>> -- > >>>> Chuck Lever > >>>> > >>>> > >>> > >>> -- > >>> To unsubscribe from this list: send the line "unsubscribe > >>> linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx > >>> More majordomo info at http://vger.kernel.org/majordomo-info.html > >> -- > >> To unsubscribe from this list: send the line "unsubscribe linux-rdma" > >> in the body of a message to majordomo@xxxxxxxxxxxxxxx More > majordomo > >> info at http://vger.kernel.org/majordomo-info.html > > > > -- > > Chuck Lever > > > > > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-rdma" > > in the body of a message to majordomo@xxxxxxxxxxxxxxx More > majordomo > > info at http://vger.kernel.org/majordomo-info.html > > -- > Chuck Lever > > -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
