Re: [Gems-users] Physical memory read raised exception

[Dan Gibson <degibson@xxxxxxxx>]

Pradeep+Liu+Gems-Users,
Ha. The ostrich algorithm. How right you are!

Regards,
Dan

On Wed, Mar 24, 2010 at 10:02 AM, Pradeep Ramachandran <pramach2@xxxxxxxx> wrote:

Hi Liu,

I have seen this error in the past from opal under varying circumstances - it essentially means that simics was not ready for the read that opal is trying to perform. However, in spite of such exceptions, I have noticed that things to work alright for the largest part. So, the simplest thing to do may be the Ostrich algorithm - try to run opal by ignoring the exception (like what Dan mentioned) and if all works fine, you don't have a problem :-).

Cheers,

Pradeep.

On Mar 24, 2010, at 9:57 AM, Dan Gibson wrote:

This error is probably raised from opal/system/hfa.C, line 553.

This is a generic routine to check whether a call into Simics completed without taking an error (unfortunately, this is called an exception, which is not the same as an exception in the target machine).

In the case you observed, Opal is attempting to read from a physical memory address that Simics doesn't like. Bummer.

I don't know why this might happen. I am not an opal expert in any fashion at all.

One thing you might try is to ignore the exception. Here is some code that will do that. You could add it to hfa.C and see if opal crashes.
  int isexcept = SIM_get_pending_exception();
  while ( !(isexcept == SimExc_No_Exception || isexcept == SimExc_Break) ) {
    SIM_clear_exception();
    isexcept = SIM_get_pending_exception();
  }

Good luck.

Regards,
Dan

On Wed, Mar 24, 2010 at 8:39 AM, Liu, Mingliang <mingliang.liu@xxxxxxxxx> wrote:

Hi guys,

 

I build my ruby and opal under gcc-4.2 and it seems that the ruby module works fine. I builded opal with some efforts including copying some functions from cache.C to cache.h and modifying Makefile.

When I load opal module and init it, I meet some warnings. Then errors occurred when I tried to start the opal module as following.

 

I have searched the user list to find that there is no solution to this question, although it occurred several times. I am a newbie to GEMS and any hints or help is heavily welcomed.

p.s. My machine is amd64-linux and the solaris10 operating system is booted under GEMS 2.1.1 (the newest version by now).

 

Regards.

================================================================

simics> instruction-fetch-mode instruction-fetch-trace

[cpu0 info] Note that on this cpu, instruction-fetch-trace is implemented using instruction-cache-access-trace with a suitable cache line size.

simics> istc-disable

Turning I-STC off and flushing old data

simics> dstc-disable

Turning D-STC off and flushing old data

simics> cpu-switch-time 1

The switch time will change to 1 cycles (for CPU-0) once all processors have synchronized.

simics> load-module ruby

successful installation of the ruby timing model.

simics> load-module opal

Queue registration cpu0

successful installation of the opal queue.

hfa_init_local done:

simics> ruby0.setparam g_NUM_PROCESSORS 1

simics> ruby0.setparam g_MEMORY_SIZE_BYTES 4294967296

simics> ruby0.init

Ruby Timing Mode

Creating event queue...

Creating event queue done

Creating system...

  Processors: 1

Creating system done

Ruby: ruby-opal link established. removing timing_model.

OpalInterface: installation successful.

Ruby initialization complete

simics> opal0.init

pstate_t: warning: control register #0 == "(null)" has simics name "g0".

pstate_t: warning: control register #1 == "(null)" has simics name "g1".

pstate_t: warning: control register #2 == "(null)" has simics name "g2".

pstate_t: warning: control register #3 == "(null)" has simics name "g3".

pstate_t: warning: control register #4 == "(null)" has simics name "g4".

pstate_t: warning: control register #5 == "(null)" has simics name "g5".

pstate_t: warning: control register #6 == "(null)" has simics name "g6".

pstate_t: warning: control register #7 == "(null)" has simics name "g7".

pstate_t: warning: control register #8 == "(null)" has simics name "o0".

pstate_t: warning: control register #9 == "(null)" has simics name "o1".

pstate_t: warning: control register #10 == "(null)" has simics name "o2".

pstate_t: warning: control register #11 == "(null)" has simics name "o3".

pstate_t: warning: control register #12 == "(null)" has simics name "o4".

pstate_t: warning: control register #13 == "(null)" has simics name "o5".

pstate_t: warning: control register #14 == "(null)" has simics name "o6".

pstate_t: warning: control register #15 == "(null)" has simics name "o7".

pstate_t: warning: control register #16 == "(null)" has simics name "l0".

pstate_t: warning: control register #17 == "(null)" has simics name "l1".

pstate_t: warning: control register #18 == "(null)" has simics name "l2".

pstate_t: warning: control register #19 == "(null)" has simics name "l3".

pstate_t: warning: control register #20 == "(null)" has simics name "l4".

pstate_t: warning: control register #21 == "(null)" has simics name "l5".

pstate_t: warning: control register #22 == "(null)" has simics name "l6".

pstate_t: warning: control register #23 == "(null)" has simics name "l7".

pstate_t: warning: control register #24 == "(null)" has simics name "i0".

pstate_t: warning: control register #25 == "(null)" has simics name "i1".

pstate_t: warning: control register #26 == "(null)" has simics name "i2".

pstate_t: warning: control register #27 == "(null)" has simics name "i3".

pstate_t: warning: control register #28 == "(null)" has simics name "i4".

pstate_t: warning: control register #29 == "(null)" has simics name "i5".

pstate_t: warning: control register #30 == "(null)" has simics name "i6".

pstate_t: warning: control register #31 == "(null)" has simics name "i7".

pstate_t: warning: control register #99 == "(null)" has simics name "ecache_error_enable".

pstate_t: warning: control register #100 == "(null)" has simics name "asynchronous_fault_status".

pstate_t: warning: control register #101 == "(null)" has simics name "asynchronous_fault_address".

pstate_t: warning: control register #102 == "(null)" has simics name "out_intr_data0".

pstate_t: warning: control register #103 == "(null)" has simics name "out_intr_data1".

pstate_t: warning: control register #104 == "(null)" has simics name "out_intr_data2".

pstate_t: warning: control register #105 == "(null)" has simics name "out_intr_data3".

pstate_t: warning: control register #106 == "(null)" has simics name "out_intr_data4".

pstate_t: warning: control register #107 == "(null)" has simics name "out_intr_data5".

pstate_t: warning: control register #108 == "(null)" has simics name "out_intr_data6".

pstate_t: warning: control register #109 == "(null)" has simics name "out_intr_data7".

Ruby: ruby-opal link established. removing timing_model.

opalinterface: doing notify callback

Opal: opal-ruby link established.

OpalInterface: installation successful.

simics> opal0.sim-start "results.opal"

[0]     PC 0xfffffffff0000020   NPC 0xfffffffff0000024  ctx 0x0

Exception error message: Physical memory read raised exception

FP registers: end

: caught exception (#7).

 

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