[llvm-dev] GSoC Proposal : Path Profiling Support

Snehasish Kumar via llvm-dev llvm-dev at lists.llvm.org
Mon Mar 21 15:07:06 PDT 2016


Hi

I am pinging to find out if there is any interest to mentor this
proposal for GSoC this year? I've submitted a draft via the GSoC
website.

David, Vedant it would be great if I could get some advice on refining
the goals and particulars of the implementation.
The version we use internally is not performance oriented and will
require refactoring.
Here is a link to the draft document [1].

Thanks,
Snehasish


[1] https://docs.google.com/document/d/18i9FvD7FSqX6tNEXb83gzc0EC_STeS3bWOVf167sFWk/edit?usp=sharing


On Wed, Mar 16, 2016 at 2:03 PM, Snehasish Kumar <ska124 at sfu.ca> wrote:
> Hi David,
>
>> Are the data below all collected when only one function is picked for
>> instrumentation?
>
> Yes, here is a list of the benchmarks and selected functions.
>
> +-----------------+----------------------------------------------------------------------------------------------+
> | blks            | _Z19BlkSchlsEqEuroNoDivfffffif
>                                           |
> +-----------------+----------------------------------------------------------------------------------------------+
> | bodytrack       |
> _ZN17ImageMeasurements11InsideErrorERK17ProjectedCylinderRK11BinaryImageRiS6_
>                |
> +-----------------+----------------------------------------------------------------------------------------------+
> | bzip2           | BZ2_compressBlock
>                                           |
> +-----------------+----------------------------------------------------------------------------------------------+
> | ferret          | image_segment
>                                           |
> +-----------------+----------------------------------------------------------------------------------------------+
> | fluidanimate    | _Z13ComputeForcesv
>                                           |
> +-----------------+----------------------------------------------------------------------------------------------+
> | freqmine        |
> _Z32FPArray_conditional_pattern_baseIhEiP7FP_treeiiT_
>                       |
> +-----------------+----------------------------------------------------------------------------------------------+
> | gcc             | bitmap_operation
>                                           |
> +-----------------+----------------------------------------------------------------------------------------------+
> | hmmer           | P7Viterbi
>                                           |
> +-----------------+----------------------------------------------------------------------------------------------+
> | lbm             | LBM_performStreamCollide
>                                           |
> +-----------------+----------------------------------------------------------------------------------------------+
> | mcf             | price_out_impl
>                                           |
> +-----------------+----------------------------------------------------------------------------------------------+
> | mcf2000         | price_out_impl
>                                           |
> +-----------------+----------------------------------------------------------------------------------------------+
> | namd            |
> _ZN20ComputeNonbondedUtil26calc_pair_energy_fullelectEP9nonbonded
>                       |
> +-----------------+----------------------------------------------------------------------------------------------+
> | povray          |
> _ZN3povL24All_Sphere_IntersectionsEPNS_13Object_StructEPNS_10Ray_StructEPNS_13istack_structE
> |
> +-----------------+----------------------------------------------------------------------------------------------+
> | sjeng           | gen
>                                           |
> +-----------------+----------------------------------------------------------------------------------------------+
> | soplex          | _ZN6soplex9CLUFactor16vSolveUrightNoNZEPdS1_Piid
>                                           |
> +-----------------+----------------------------------------------------------------------------------------------+
> | sphinx          | vector_gautbl_eval_logs3
>                                           |
> +-----------------+----------------------------------------------------------------------------------------------+
> | streamcluster   | _Z5pgainlP6PointsdPliP17pthread_barrier_t
>                                           |
> +-----------------+----------------------------------------------------------------------------------------------+
> | swaptions       | _Z21HJM_Swaption_BlockingPddddddiidS_PS_llii
>                                           |
> +-----------------+----------------------------------------------------------------------------------------------+
> | h264ref         | dct_luma_16x16
>                                           |
> +-----------------+----------------------------------------------------------------------------------------------+
>
>> Do you have data when such manual selection is not done?
>
> At the moment, I do not.
>
>>
>> thanks,
>>
>> David
>>
>>
>>>
>>> numpaths = Number of possible paths
>>> epp+compile = Time taken to compute encoding, insert instrumentation and
>>> compile to executable
>>> compile = Time taken to compile to executable
>>> execpaths = Number of paths dynamically executed
>>> epp-exec-time = Execution time with instrumentation
>>> exec-time = Normal execution time
>>> epp-bin-size = Size of instrumented binary in bytes
>>> bin-size = Size of binary
>>> ** size of shared library in bytes = 598042
>>>
>>>
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | benchmark     | numpaths | epp+compile | compile   | execpaths |
>>> epp-exec-time | exec-time | epp-bin-size | bin-size |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | blks          | 2        | 0m1.036s    | 0m1.008s  | 2         |
>>> 0m3.643s      | 0m3.205s  | 155931       | 155459   |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | bodytrack     | 29       | 0m4.907s    | 0m4.881s  | 5         |
>>> 0m14.786s     | 0m1.943s  | 2125256      | 2124224  |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | bzip2         | 60       | 0m1.274s    | 0m1.268s  | 3         |
>>> 0m9.441s      | 0m9.624s  | 259125       | 258477   |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | ferret        | 360921   | 0m26.208s   | 0m26.102s | 40        |
>>> 0m10.342s     | 0m6.224s  | 8342571      | 8338588  |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | fluidanimate  | 384117   | 0m0.895s    | 0m0.869s  | 88        |
>>> 0m56.631s     | 0m1.294s  | 202702       | 197878   |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | freqmine      | 45       | 0m1.220s    | 0m1.214s  | 18        |
>>> 0m22.150s     | 0m5.515s  | 278615       | 277656   |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | gcc           | 6026     | 0m31.941s   | 0m31.327s | 125       |
>>> 1m30.139s     | 0m36.601s | 6991413      | 6991245  |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | hmmer         | 1882     | 0m3.193s    | 0m3.232s  | 65        |
>>> 0m58.911s     | 0m2.474s  | 744510       | 742806   |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | mcf           | 230      | 0m0.838s    | 0m0.830s  | 10        |
>>> 0m11.097s     | 0m3.074s  | 162680       | 161736   |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | mcf2000       | 1155     | 0m0.859s    | 0m0.853s  | 26        |
>>> 0m24.169s     | 0m4.625s  | 166092       | 165213   |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | povray        | 17       | 0m8.543s    | 0m8.552s  | 4         |
>>> 9m24.562s     | 5m39.295s | 2388152      | 2387960  |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | sjeng         | 158740   | 0m1.648s    | 0m1.637s  | 280       |
>>> 0m20.786s     | 0m5.229s  | 368841       | 368009   |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | soplex        | 30       | 0m4.849s    | 0m4.848s  | 24        |
>>> 7m28.151s     | 4m10.813s | 1244775      | 1242063  |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | sphinx        | 26       | 0m2.212s    | 0m2.198s  | 5         |
>>> 1m36.291s     | 0m13.811s | 543534       | 543358   |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | streamcluster | 21121728 | 0m0.947s    | 0m0.908s  | 33        |
>>> 0m50.212s     | 0m5.986s  | 191981       | 185438   |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | swaptions     | 20655    | 0m0.965s    | 0m0.950s  | 13        |
>>> 0m0.263s      | 0m0.178s  | 193841       | 184274   |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | h264ref       | 24130    | 0m4.278s    | 0m4.272s  | 76        |
>>> 3m26.701s     | 3m4.461s  | 816660       | 812396   |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | lbm           | 8        | 0m0.824s    | 0m0.815s  | 5         |
>>> 6m29.685s     | 1m39.180s | 150871       | 150327   |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>> | namd          | 59598954 | 0m4.124s    | 0m4.139s  | 43        |
>>> 18m36.447s    | 6m50.288s | 925863       | 925271   |
>>>
>>> +---------------+----------+-------------+-----------+-----------+---------------+-----------+--------------+----------+
>>>
>>>
>>>
>>> > > Open Issues :
>>> > > + Update PathProfileInfo on CFG transformations ?
>>>
>>> > Could you clarify what this means?
>>>
>>> Changing the control flow graph of a routine may invalidate collected path
>>> profiles. For example, splitting a block with an unconditional branch does
>>> not change the profile, but introducing a conditional branch invalidates the
>>> profile. The issue I would like to address is which transformations should
>>> we allow as safe transformations and how should we update the internal path
>>> profile data structures if we allow this at all.
>>>
>>> > > + Verify with PGOEdge info ?
>>>
>>> > Ditto.
>>>
>>> Verification with PGOEdge info implies that the edge frequencies derived
>>> from path profiles and via instrprof should be equal.
>>>
>>> > > + Handle setjmp, longjmp, early program termination, noreturn calls
>>>
>>> > How do you handle indirect calls?
>>>
>>> No special handling of indirect calls as path profiles are
>>> intra-procedural and control returns to same basic block
>>> after call in the general case. For the above mentioned cases, control may
>>> not return.
>>>
>>>
>>> Regards,
>>> Snehasish
>>> _______________________________________________
>>> LLVM Developers mailing list
>>> llvm-dev at lists.llvm.org
>>> http://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-dev
>>
>>
>>
>> _______________________________________________
>> LLVM Developers mailing list
>> llvm-dev at lists.llvm.org
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>>


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