Re: [ewg] nfsrdma fails to write big file,

[Tom Tucker <tom-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org>]

Vu Pham wrote:
> Tom,
>
> Did you make any change to have bonnie++, dd of a 10G file and vdbench
> concurrently run & finish?
>
>   

No I did not but my disk subsystem is pretty slow, so it might be that I 
just don't have fast enough storage.

> I keep hitting the WQE overflow error below.
> I saw that most of the requests have two chunks (32K chunk and
> some-bytes chunk), each chunk requires an frmr + invalidate wrs;
> However, you set ep->rep_attr.cap.max_send_wr = cdata->max_requests and
> then for frmr case you do
> ep->rep_atrr.cap.max_send_wr *=3; which is not enough. Moreover, you
> also set ep->rep_cqinit = max_send_wr/2 for send completion signal which
> causes the wqe overflow happened faster.
>
>   


> After applying the following patch, I have thing vdbench, dd, and copy
> 10g_file running overnight
>
> -vu
>
>
> --- ofa_kernel-1.5.1.orig/net/sunrpc/xprtrdma/verbs.c   2010-02-24
> 10:41:22.000000000 -0800
> +++ ofa_kernel-1.5.1/net/sunrpc/xprtrdma/verbs.c        2010-02-24
> 10:03:18.000000000 -0800
> @@ -649,8 +654,15 @@
>         ep->rep_attr.cap.max_send_wr = cdata->max_requests;
>         switch (ia->ri_memreg_strategy) {
>         case RPCRDMA_FRMR:
> -               /* Add room for frmr register and invalidate WRs */
> -               ep->rep_attr.cap.max_send_wr *= 3;
> +               /* 
> +                * Add room for frmr register and invalidate WRs
> +                * Requests sometimes have two chunks, each chunk
> +                * requires to have different frmr. The safest
> +                * WRs required are max_send_wr * 6; however, we
> +                * get send completions and poll fast enough, it
> +                * is pretty safe to have max_send_wr * 4. 
> +                */
> +               ep->rep_attr.cap.max_send_wr *= 4;
>                 if (ep->rep_attr.cap.max_send_wr > devattr.max_qp_wr)
>                         return -EINVAL;
>                 break;
> @@ -682,7 +694,8 @@
>                 ep->rep_attr.cap.max_recv_sge);
>
>         /* set trigger for requesting send completion */
> -       ep->rep_cqinit = ep->rep_attr.cap.max_send_wr/2 /*  - 1*/;
> +       ep->rep_cqinit = ep->rep_attr.cap.max_send_wr/4;
> +       
>         switch (ia->ri_memreg_strategy) {
>         case RPCRDMA_MEMWINDOWS_ASYNC:
>         case RPCRDMA_MEMWINDOWS:
>
>
>   
Erf. This is client code. I'll take a look at this and see if I can 
understand what Talpey was up to.

Tom
>   


>
>
>   
>> -----Original Message-----
>> From: ewg-bounces-ZwoEplunGu1OwGhvXhtEPSCwEArCW2h5@public.gmane.org [mailto:ewg-
>> bounces-ZwoEplunGu1OwGhvXhtEPSCwEArCW2h5@public.gmane.org] On Behalf Of Vu Pham
>> Sent: Monday, February 22, 2010 12:23 PM
>> To: Tom Tucker
>> Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; Mahesh Siddheshwar;
>> ewg-ZwoEplunGu1OwGhvXhtEPSCwEArCW2h5@public.gmane.org
>> Subject: Re: [ewg] nfsrdma fails to write big file,
>>
>> Tom,
>>
>> Some more info on the problem:
>> 1. Running with memreg=4 (FMR) I can not reproduce the problem
>> 2. I also see different error on client
>>
>> Feb 22 12:16:55 mellanox-2 rpc.idmapd[5786]: nss_getpwnam: name
>> 'nobody'
>> does not map into domain 'localdomain'
>> Feb 22 12:16:55 mellanox-2 kernel: QP 0x70004b: WQE overflow
>> Feb 22 12:16:55 mellanox-2 kernel: QP 0x6c004a: WQE overflow
>> Feb 22 12:16:55 mellanox-2 kernel: QP 0x6c004a: WQE overflow
>> Feb 22 12:16:55 mellanox-2 kernel: RPC: rpcrdma_ep_post: ib_post_send
>> returned -12 cq_init 48 cq_count 32
>> Feb 22 12:17:00 mellanox-2 kernel: RPC:       rpcrdma_event_process:
>> send WC status 5, vend_err F5
>> Feb 22 12:17:00 mellanox-2 kernel: rpcrdma: connection to
>> 13.20.1.9:20049 closed (-103)
>>
>> -vu
>>
>>     
>>> -----Original Message-----
>>> From: Tom Tucker [mailto:tom-7bPotxP6k4+P2YhJcF5u+vpXobYPEAuW@public.gmane.org]
>>> Sent: Monday, February 22, 2010 10:49 AM
>>> To: Vu Pham
>>> Cc: linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org; Mahesh Siddheshwar;
>>> ewg-ZwoEplunGu1OwGhvXhtEPSCwEArCW2h5@public.gmane.org
>>> Subject: Re: [ewg] nfsrdma fails to write big file,
>>>
>>> Vu Pham wrote:
>>>       
>>>> Setup:
>>>> 1. linux nfsrdma client/server with OFED-1.5.1-20100217-0600,
>>>>         
>>> ConnectX2
>>>       
>>>> QDR HCAs fw 2.7.8-6, RHEL 5.2.
>>>> 2. Solaris nfsrdma server svn 130, ConnectX QDR HCA.
>>>>
>>>>
>>>> Running vdbench on 10g file or *dd if=/dev/zero of=10g_file bs=1M
>>>> count=10000*, operation fail, connection get drop, client cannot
>>>> re-establish connection to server.
>>>> After rebooting only the client, I can mount again.
>>>>
>>>> It happens with both solaris and linux nfsrdma servers.
>>>>
>>>> For linux client/server, I run memreg=5 (FRMR), I don't see
>>>>         
> problem
>   
>>> with
>>>       
>>>> memreg=6 (global dma key)
>>>>
>>>>
>>>>         
>>> Awesome. This is the key I think.
>>>
>>> Thanks for the info Vu,
>>> Tom
>>>
>>>
>>>       
>>>> On Solaris server snv 130, we see problem decoding write request
>>>>         
> of
>   
>>> 32K.
>>>       
>>>> The client send two read chunks (32K & 16-byte), the server fail
>>>>         
> to
>   
>>> do
>>>       
>>>> rdma read on the 16-byte chunk (cqe.status = 10 ie.
>>>> IB_WC_REM_ACCCESS_ERROR); therefore, server terminate the
>>>>         
>> connection.
>>     
>>> We
>>>       
>>>> don't see this problem on nfs version 3 on Solaris. Solaris server
>>>>         
>>> run
>>>       
>>>> normal memory registration mode.
>>>>
>>>> On linux client, I see cqe.status = 12 ie. IB_WC_RETRY_EXC_ERR
>>>>
>>>> I added these notes in bug #1919 (bugs.openfabrics.org) to track
>>>>         
>> the
>>     
>>>> issue.
>>>>
>>>> thanks,
>>>> -vu
>>>> _______________________________________________
>>>> ewg mailing list
>>>> ewg-ZwoEplunGu1OwGhvXhtEPSCwEArCW2h5@public.gmane.org
>>>> http://lists.openfabrics.org/cgi-bin/mailman/listinfo/ewg
>>>>
>>>>         
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