[Nouveau] Debugging INVALID_OPCODE / MULTIPLE_WARP_ERRORS ?

[Hans de Goede]

Hi,

On 15-12-15 20:04, Ilia Mirkin wrote:
> Also, where's the exit op? Perhaps what's happening is that you don't
> have an exit and it just goes off executing into the ether?

Sorry I only included a small bit of the program in my original mail
because I found the use of "MOV" instructions to load constants
suspicious, is that normal ?

I've put a log with NV50_PROG_DEBUG=1 output here:

https://fedorapeople.org/~jwrdegoede/nbody.log

nvdisasm -b SM30 for the generated binary code is here:

https://fedorapeople.org/~jwrdegoede/nbody.disasm

There are already .tgsi, .hex and .bin files there if
you find those easier to use then the
NV50_PROG_DEBUG=1 output.


>
> On Tue, Dec 15, 2015 at 12:00 PM, Ilia Mirkin <imirkin at alum.mit.edu> wrote:
>> A few things that stand out:
>>
>>    0: ld u32 %r219 c0[0x0000000000000000+0x0] (0)
>>
>> wtf is that 0x0000000000000 thing doing there? Was it a %rX which got
>> constant-folded into 0? That indirectness should have then been
>> removed... that said, the final encoding looks fine.

I don't know, maybe there is a hint in the log file?

Regards,

Hans


>>
>> I believe that kepler has this launch descriptor thing too... is that
>> being set correctly? Please generate a mmt trace, and we can see if
>> anything stands out compared to a blob trace that also does compute.
>>
>> Cheers,
>>
>>    -ilia
>>
>> On Tue, Dec 15, 2015 at 9:15 AM, Hans de Goede <hdegoede at redhat.com> wrote:
>>> Hi all,
>>>
>>> As part of my compute work I'm trying to get some TGSI compute
>>> code to work. The code from mesa/src/gallium/tests/trivial.c
>>> works.
>>>
>>> So now I'm trying to get a "native" tgsi kernel to run via
>>> clover, I'm using Francisco's nbody.c example for this:
>>>
>>> https://fedorapeople.org/~jwrdegoede/nbody.c
>>>
>>> Which does not work, at first I thought there was an issue
>>> with the setup of the input / output buffers, but that seems to
>>> work fine, and moreover I finally got the smart idea to look
>>> in dmesg, which says:
>>>
>>> [ 9920.802435] nouveau 0000:01:00.0: gr: TRAP ch 6 [007f7fa000 nbody[31881]]
>>> [ 9920.802449] nouveau 0000:01:00.0: gr: GPC0/TPC0/MP trap: global 00000000
>>> [] warp 10009 [INVALID_OPCODE]
>>> [ 9920.802456] nouveau 0000:01:00.0: gr: GPC0/TPC1/MP trap: global 00000004
>>> [MULTIPLE_WARP_ERRORS] warp 20009 [INVALID_OPCODE]
>>>
>>> and repeats that for every "step" in the nobody simulation, this is on a
>>> gk107 card.
>>>
>>> So that seems to be the real problem, since the
>>> error says "INVALID_OPCODE", I've put the tgsi code from nbody.c
>>> through "nouveau_compiler -a e4" and then run "nvdisasm -b SM30"
>>> on it, but the output looks ok. There is a 8 byte sequence which does
>>> not get decoded every 64 bytes but AFAIK that is the scheduling info,
>>> so that should be fine.
>>>
>>> One thing which does stand out is that this:
>>>
>>>    0: ld u32 %r219 c0[0x0000000000000000+0x0] (0)
>>>    1: ld u32 %r222 c0[0x4] (0)
>>>    2: ld u64 { %r225 %r228 } c0[0x8] (0)
>>>    3: ld u32 %r234 c0[0x10] (0)
>>>
>>> Gets translated into (nvdisasm output) :
>>>
>>>          /*0008*/                   LDC R4, c[0x0][0x0];
>>> /* 0x1400000003f11c86 */
>>>          /*0010*/                   MOV R2, c[0x0][0x4];
>>> /* 0x2800400010009de4 */
>>>          /*0018*/                   LDC.64 R0, c[0x0][0x8];
>>> /* 0x1400000023f01ca6 */
>>>          /*0020*/                   MOV R3, c[0x0][0x10];
>>> /* 0x280040004000dde4 */
>>>
>>> Where I would expect for LDC instructions, could that be the problem ?
>>>
>>> If that is not the problem, then hints how to debug this further would be
>>> greatly appreciated.
>>>
>>> Regards,
>>>
>>> Hans
>>> _______________________________________________
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