> On Sept. 16, 2015, 4:36 p.m., Nilay Vaish wrote:
> > src/cpu/o3/probe/elastic_trace.hh, line 112
> > <http://reviews.gem5.org/r/3027/diff/1/?file=48955#file48955line112>
> >
> >     flushTraces()?

Fixed.


> On Sept. 16, 2015, 4:36 p.m., Nilay Vaish wrote:
> > src/cpu/o3/probe/elastic_trace.hh, line 236
> > <http://reviews.gem5.org/r/3027/diff/1/?file=48955#file48955line236>
> >
> >     Instead of short int, should this not be PhysRegIndex?

Fixed.


> On Sept. 16, 2015, 4:36 p.m., Nilay Vaish wrote:
> > src/cpu/o3/probe/elastic_trace.hh, line 254
> > <http://reviews.gem5.org/r/3027/diff/1/?file=48955#file48955line254>
> >
> >     I think o3 is not required.

Fixed.


> On Sept. 16, 2015, 4:36 p.m., Nilay Vaish wrote:
> > src/cpu/o3/probe/elastic_trace.hh, line 271
> > <http://reviews.gem5.org/r/3027/diff/1/?file=48955#file48955line271>
> >
> >     Cycles?

Actually the unit is ticks so using Cycles would be misleading. I want to use 
an int here to trap -ve values, therefore not using Tick.


> On Sept. 16, 2015, 4:36 p.m., Nilay Vaish wrote:
> > src/cpu/o3/probe/elastic_trace.hh, line 304
> > <http://reviews.gem5.org/r/3027/diff/1/?file=48955#file48955line304>
> >
> >     no o3.

Fixed


> On Sept. 16, 2015, 4:36 p.m., Nilay Vaish wrote:
> > src/cpu/o3/probe/elastic_trace.hh, lines 313-316
> > <http://reviews.gem5.org/r/3027/diff/1/?file=48955#file48955line313>
> >
> >     No o3, we are already in the o3 directory.

Fixed.


> On Sept. 16, 2015, 4:36 p.m., Nilay Vaish wrote:
> > src/cpu/o3/probe/elastic_trace.cc, lines 56-57
> > <http://reviews.gem5.org/r/3027/diff/1/?file=48956#file48956line56>
> >
> >     nullptr

Fixed.


- Radhika


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On Aug. 11, 2015, 9:05 p.m., Curtis Dunham wrote:
> 
> -----------------------------------------------------------
> This is an automatically generated e-mail. To reply, visit:
> http://reviews.gem5.org/r/3027/
> -----------------------------------------------------------
> 
> (Updated Aug. 11, 2015, 9:05 p.m.)
> 
> 
> Review request for Default.
> 
> 
> Repository: gem5
> 
> 
> Description
> -------
> 
> The elastic trace is a type of probe listener and listens to probe points
> in multiple stages of the O3CPU. The notify method is called on a probe
> point typically when an instruction successfully progresses through that
> stage.
> 
> As different listener methods mapped to the different probe points execute,
> relevant information about the instruction, e.g. timestamps and register
> accesses, are captured and stored in temporary InstExecInfo class objects.
> When the instruction progresses through the commit stage, the timing and the
> dependency information about the instruction is finalised and encapsulated in
> a struct called TraceInfo. TraceInfo objects are collected in a list instead
> of writing them out to the trace file one a time. This is required as the
> trace is processed in chunks to evaluate order dependencies and computational
> delay in case an instruction does not have any register dependencies. By this
> we achieve a simpler algorithm during replay because every record in the
> trace can be hooked onto a record in its past. The instruction dependency
> trace is written out as a protobuf format file. A second trace containing
> fetch requests at absolute timestamps is written to a separate protobuf
> format file.
> 
> If the instruction is not executed then it is not added to the trace.
> The code checks if the instruction had a fault, if it predicated
> false and thus previous register values were restored or if it was a
> load/store that did not have a request (e.g. when the size of the
> request is zero). In all these cases the instruction is set as
> executed by the Execute stage and is picked up by the commit probe
> listener. But a request is not issued and registers are not written.
> So practically, skipping these should not hurt the dependency modelling.
> 
> If squashing results in squashing younger instructions, it may happen that
> the squash probe discards the inst and removes it from the temporary
> store but execute stage deals with the instruction in the next cycle which
> results in the execute probe seeing this inst as 'new' inst. A sequence
> number of the last processed trace record is used to trap these cases and
> not add to the temporary store.
> 
> The elastic instruction trace and fetch request trace can be read in and
> played back by the TraceCPU.
> 
> 
> Diffs
> -----
> 
>   src/cpu/o3/probe/ElasticTrace.py PRE-CREATION 
>   src/cpu/o3/probe/SConscript b998b5a6c5f59b41e0c0997ca1bebe37717ad551 
>   src/cpu/o3/probe/elastic_trace.hh PRE-CREATION 
>   src/cpu/o3/probe/elastic_trace.cc PRE-CREATION 
>   src/proto/SConscript b998b5a6c5f59b41e0c0997ca1bebe37717ad551 
>   src/proto/inst_dep_record.proto PRE-CREATION 
>   src/proto/packet.proto b998b5a6c5f59b41e0c0997ca1bebe37717ad551 
> 
> Diff: http://reviews.gem5.org/r/3027/diff/
> 
> 
> Testing
> -------
> 
> 
> Thanks,
> 
> Curtis Dunham
> 
>

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