Re: [Gems-users] ATMTP: Problem with strange Transaction-Aborts

[Philipp Tölke <toelke+gems@xxxxxxxxx>]

Hi,

> I ran ATMTP with no problems on microbenchmarks provided from GEMS.
> $GEMS/microbenchmarks/atmtp_examples

The microbenchmarks work correctly.

> Did your compiled benchmark have TLB warm up or TLB miss handling?

I don't think so.

But for this to matter, the failing instruction has to be on a different
page, than the chkpt-instruction, which is unlikely, as they are only a
few bytes apart. Also, I see no "Address not in TLB"-Errors (I saw them,
but not in these circumstances.)

> Did you check your compiled benchmark (332_ammp)
> did not call malloc/new from a transaction?

As I said, the abort happens in the context of begin_transaction:

   134f4:       30 50 00 04     chkpt 
   134f8:       01 00 00 00     nop 
   134fc:       10 80 00 03     b  13508 <begin_transaction+0x20>
   13500:       90 10 20 01     mov  1, %o0
   13504:       90 10 00 00     mov  %g0, %o0
   13508:       a0 10 00 08     mov  %o0, %l0

The simulation hangs on the instruction 0x13508.

| 6826445428   0 [0,0] TID -1 XACT ABORT 0 caused by 0 [ 0, 0 ] xid: 0
| address: [0x0, line 0x0] delay: 6826445428  PC [0x0, line 0x0]  *PC 
| 0x0 'illtrap 0'

Or does this point to a TLB-Miss?

I am concerned about two points:
- in the above error-message, there are only zeros.
- after this message, the simulation hangs. ^C^C cancels the simulation,
  but not in a recoverable way

> As you know well, syscall is not allowed from GEMS TM (inc. ATMTP).
> Most of the failures I had belong to above two problems.

I'm quite sure, this is not the issue in this case.

Thank you for you're insights!

Regards,
-- 
Philipp Tölke

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