Re: [PATCH net-next v3 00/10] optimize the parallelism of SMC-R connections

[Jan Karcher <jaka@linux.ibm.com>]

Hi D. Wythe,

I reply with the feedback on your fix to your v4 fix.

Regarding your questions:
We are aware of this situation and we are currently evaluating how we 
want to deal with SMC-D in the future because as of right now i can 
understand your frustration regarding the SMC-D testing.
Please give me some time to hit up the right people and collect some 
information to answer your question. I'll let you know as soon as i have 
an answer.

Thanks
- Jan

On 21/10/2022 17:57, D. Wythe wrote:
> Hi Jan,
> 
> Sorry for this bug. It's my bad to do not enough code checking, here is 
> the problems:
> 
> int __init smc_core_init(void)
> {
>          int i;
> 
>          /* init smc lgr decision maker builder */
>          for (i = 0; i < SMC_TYPE_D; i++)
> 
> 
> i < SMC_TYPE_D should change to i <= SMC_TYPE_D, otherwise the SMC-D 
> related
> map has not init yet. i thinks the two bugs was all caused by it.
> 
> 
> I has reproduced the first problem and verified that it can be fixed.
> Please help me to see if the SMC-D problem can be fixed too after this 
> change, thx.
> 
> By the way, Is there any way to simulate SMC-D dev for testing? All of 
> our problems are caused by poor consideration on SMC-D.
> In fact, we have some SMC-D related work plans in the future. It seems 
> not a perfect way to bother you every time.
> 
> 
> Best Wishes.
> D. Wythe
> 
> On 10/21/22 7:57 PM, Jan Karcher wrote:
>>
>>
>> On 20/10/2022 09:00, D. Wythe wrote:
>>>
>>> Hi Jan,
>>>
>>> Sorry for the long delay, The main purpose of v3 is to put optimizes 
>>> also works on SMC-D, dues to the environment,
>>> I can only tests it in SMC-R, so please help us to verify the 
>>> stability and functional in SMC-D,
>>> Thanks a lot.
>>>
>>> If you have any problems, please let us know.
>>>
>>> Besides, PATCH bug fixes need to be reordered. After the code review 
>>> passes and the SMC-D test goes stable, I will adjust it
>>> in next serial.
>>>
>>>
>>
>> Hi D. Wythe,
>>
>> thank you again for your submission. I ran the first tests and here 
>> are my findings:
>>
>> For SMC-R we are facing problems during unloading of the smc module:
>>
>> vvvvvvvvvv
>>
>> [root@testsys10 ~]# dmesg -C
>> [root@testsys10 ~]# dmesg
>> [root@testsys10 ~]# rmmod ism
>> [root@testsys10 ~]# rmmod smc_diag
>> [root@testsys10 ~]# dmesg
>> [   51.671365] smc: removing smcd device 1522:00:00.0
>> [root@testsys10 ~]# rmmod smc
>> [root@testsys10 ~]# dmesg
>> [   51.671365] smc: removing smcd device 1522:00:00.0
>> [   65.378445] NET: Unregistered PF_SMC protocol family
>> [   65.378463] ------------[ cut here ]------------
>> [   65.378465] WARNING: CPU: 0 PID: 1155 at kernel/workqueue.c:3066 
>> __flush_work.isra.0+0x28a/0x298
>> [   65.378476] Modules linked in: nft_fib_inet nft_fib_ipv4 
>> nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 nf_reject_ipv6 
>> nft_reject nft_ct nft_chain_nat nf_nat mlx5_ib nf_conntrack ib_uverbs 
>> nf_defrag_ipv6 nf_defrag_ipv4 ip_set nf_tables nfnetlink mlx5_core 
>> smc(-) ib_core vfio_ccw s390_trng mdev vfio_iommu_type1 vfio 
>> sch_fq_codel configfs ghash_s390 prng chacha_s390 libchacha aes_s390 
>> des_s390 libdes sha3_512_s390 sha3_256_s390 sha512_s390 sha256_s390 
>> sha1_s390 sha_common pkey zcrypt rng_core autofs4 [last unloaded: 
>> smc_diag]
>> [   65.378509] CPU: 0 PID: 1155 Comm: rmmod Not tainted 
>> 6.1.0-rc1-00035-g9980a965416f #4
>> [   65.378514] Hardware name: IBM 8561 T01 701 (z/VM 7.2.0)
>> [   65.378517] Krnl PSW : 0704c00180000000 00000000f9d5f17e 
>> (__flush_work.isra.0+0x28e/0x298)
>> [   65.378523]            R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 
>> CC:0 PM:0 RI:0 EA:3
>> [   65.380675] Krnl GPRS: 8000000000000001 0000000000000000 
>> 000003ff7fd40270 0000000000000000
>> [   65.380683]            0000038000c73d70 000e002100000000 
>> 0000000000000000 0000000000000001
>> [   65.380686]            0000038000c73d70 0000000000000000 
>> 000003ff7fd40270 000003ff7fd40270
>> [   65.380688]            000000009b8d2100 000003ffe38f98f8 
>> 0000038000c73cd0 0000038000c73c30
>> [   65.380697] Krnl Code: 00000000f9d5f172: a7780000            lhi %r7,0
>>                            00000000f9d5f176: a7f4ff7b            brc 
>> 15,00000000f9d5f06c
>>                           #00000000f9d5f17a: af000000            
>> mc      0,0
>>                           >00000000f9d5f17e: a7780000            lhi 
>> %r7,0
>>                            00000000f9d5f182: a7f4ff75            brc 
>> 15,00000000f9d5f06c
>>                            00000000f9d5f186: 0707                bcr 
>> 0,%r7
>>                            00000000f9d5f188: c004005daa34        brcl 
>> 0,00000000fa9145f0
>>                            00000000f9d5f18e: ebaff0680024        stmg 
>> %r10,%r15,104(%r15)
>> [   65.380773] Call Trace:
>> [   65.380774]  [<00000000f9d5f17e>] __flush_work.isra.0+0x28e/0x298
>> [   65.380779]  [<00000000f9d61228>] __cancel_work_timer+0x130/0x1c0
>> [   65.380782]  [<00000000fa46b1b4>] 
>> rhashtable_free_and_destroy+0x2c/0x170
>> [   65.380787]  [<000003ff7fd3a08e>] smc_exit+0x3e/0x1b8 [smc]
>> [   65.380804]  [<00000000f9de946a>] __do_sys_delete_module+0x1a2/0x298
>> [   65.380809]  [<00000000fa8f85ac>] __do_syscall+0x1d4/0x200
>> [   65.380814]  [<00000000fa907722>] system_call+0x82/0xb0
>> [   65.380817] Last Breaking-Event-Address:
>> [   65.380818]  [<00000000f9d5ef24>] __flush_work.isra.0+0x34/0x298
>> [   65.380820] ---[ end trace 0000000000000000 ]---
>> [   65.380828] smc: removing ib device mlx5_0
>> [   65.380833] smc: removing ib device mlx5_1
>>
>> ^^^^^^^^^^
>>
>> For SMC-D it seems like your decisionmaker is causing some troubles 
>> (crash). I did not have the time yet to look into it, i still dump you 
>> the console log - maybe you're seeing the problem faster then me:
>>
>>
>> vvvvvvvvvv
>>
>> [  135.528259] smc-tests: test_cs_security started
>> [  136.397056] illegal operation: 0001 ilc:1 [#1] SMP
>> [  136.397064] Modules linked in: tcp_diag inet_diag ism mlx5_ib 
>> ib_uverbs mlx5_core smc_diag smc ib_core vmur nft_fib_inet nft_fib_
>> ipv4 nft_fib_ipv6 nft_fib nft_reject_inet nf_reject_ipv4 
>> nf_reject_ipv6 nft_reject nft_ct nft_chain_nat nf_nat nf_conntrack 
>> nf_defra
>> g_ipv6 nf_defrag_ipv4 ip_set nf_tab
>> [  136.397093] CPU: 0 PID: 9 Comm: kworker/0:1 Not tainted 
>> 6.1.0-rc1-00035-g1c11cab281ca #4
>> [  136.397098] Hardware name: IBM 8561 T01 701 (z/VM 7.2.0)
>> [  136.397100] Workqueue: smc_hs_wq smc_listen_work [smc]
>> [  136.397123] Krnl PSW : 0704e00180000000 0000000000000002 (0x2)
>> [  136.397128]            R:0 T:1 IO:1 EX:1 Key:0 M:1 W:0 P:0 AS:3 
>> CC:2 PM:0 RI:0 EA:3
>> [  136.397133] Krnl GPRS: 0000000000000001 0000000000000000 
>> 00000000a5670600 0000000000000000
>>
>> [  136.398410]            0000000000000000 000003ff7feee620 
>> 00000000000000c8 0000000000000000
>> [  136.398417]            000003ff7feed2b8 00000000a5670600 
>> 000003ff7feed168 000003ff7fed1628
>> [  136.398420]            0000000080334200 0000000000000001 
>> 000003ff7fed3ab0 0000037fffb5fa30
>> [  136.398425] Krnl Code:#0000000000000000: 0000                illegal
>> [  136.398425]           >0000000000000002: 0000                illegal
>> [  136.398425]            0000000000000004: 0000                illegal
>> [  136.398425]            0000000000000006: 0000                illegal
>> [  136.398425]            0000000000000008: 0000                illegal
>> [  136.398425]            000000000000000a: 0000                illegal
>> [  136.398425]            000000000000000c: 0000                illegal
>> [  136.398425]            000000000000000e: 0000                illegal
>> [  136.398465] Call Trace:
>> [  136.398469]  [<0000000000000002>] 0x2
>> [  136.398472] ([<00000001790fdbde>] release_sock+0x6e/0xd8)
>> [  136.398482]  [<000003ff7fed746a>] smc_conn_create+0xc2/0x9d8 [smc]
>> 01: HCPGSP2629I The virtual machine is placed in CP mode due to a SIGP 
>> stop from CPU 01.
>> 01: HCPGSP2629I The virtual machine is placed in CP mode due to a SIGP 
>> stop from CPU 00.
>>
>> [  136.408436]  [<000003ff7fec8206>] 
>> smc_find_ism_v2_device_serv+0x186/0x288 [smc]
>> [  136.408444]  [<000003ff7fec8336>] smc_listen_find_device+0x2e/0x370 
>> [smc]
>> [  136.408452]  [<000003ff7fecaa8a>] smc_listen_work+0x2ca/0x580 [smc]
>> [  136.408459]  [<00000001788481e8>] process_one_work+0x200/0x458
>> [  136.408466]  [<000000017884896e>] worker_thread+0x66/0x480
>> [  136.408470]  [<0000000178851888>] kthread+0x108/0x110
>> [  136.408474]  [<00000001787d72cc>] __ret_from_fork+0x3c/0x58
>> [  136.408478]  [<00000001793ef75a>] ret_from_fork+0xa/0x40
>> [  136.408484] Last Breaking-Event-Address:
>> [  136.408486]  [<000003ff7fed3aae>] 
>> smc_get_or_create_lgr_decision_maker.constprop.0+0xe6/0x398 [smc]
>> [  136.408495] Kernel panic - not syncing: Fatal exception in interrupt
>>
>> ^^^^^^^^^^
>>
>> - Jan