DTrace asm profiler for Mac OS X

[Vsevolod Tolstopyatov]

>Then, it still not found lines. I thought JMH was adding the correct
PrintAssembly flags when forking. But the issue seems to be similar with
the warning I had for perfasm.
Yes, that's your PrintAssembly-related issues.

Just ran ConcurrentMapThroughput with dtraceasm on latest JCTools,
everything seems fine

--
Best regards,
Tolstopyatov Vsevolod

On Wed, Jan 17, 2018 at 3:58 PM, Henri Tremblay <henri.tremblay at gmail.com>
wrote:

> Well found! It seems much better.
>
> Then, it still not found lines. I thought JMH was adding the correct
> PrintAssembly flags when forking. But the issue seems to be similar with
> the warning I had for perfasm.
>
> ERROR: No address lines detected in assembly capture, make sure your JDK
> is PrintAssembly-enabled:
>     https://wiki.openjdk.java.net/display/HotSpot/PrintAssembly
>
> Perf output processed (skipped 2.531 seconds):
>  Column 1: sampled_pc (11033 events)
>
> Hottest code regions (>10.00% "sampled_pc" events):
>
> ....[Hottest Region 1]............................
> ..................................................
> [unknown], [unknown] (231 bytes)
>
>  <no assembly is recorded, native region>
> ............................................................
> ........................................
>  22.54%  <total for region 1>
>
> ....[Hottest Region 2]............................
> ..................................................
> [unknown], [unknown] (134 bytes)
>
>  <no assembly is recorded, native region>
> ............................................................
> ........................................
>  11.31%  <total for region 2>
>
> ....[Hottest Region 3]............................
> ..................................................
> [unknown], [unknown] (41 bytes)
>
>  <no assembly is recorded, native region>
> ............................................................
> ........................................
>  10.39%  <total for region 3>
>
> ....[Hottest Region 4]............................
> ..................................................
> [unknown], [unknown] (417 bytes)
>
>  <no assembly is recorded, native region>
> ............................................................
> ........................................
>  10.27%  <total for region 4>
>
> ....[Hottest Regions]....................................................
> ...........................
>  22.54%  [unknown]  [unknown] (231 bytes)
>  11.31%  [unknown]  [unknown] (134 bytes)
>  10.39%  [unknown]  [unknown] (41 bytes)
>  10.27%  [unknown]  [unknown] (417 bytes)
>   8.45%  [unknown]  [unknown] (396 bytes)
>   5.71%  [unknown]  [unknown] (43 bytes)
>   5.66%  [unknown]  [unknown] (55 bytes)
>   5.45%  [unknown]  [unknown] (84 bytes)
>   4.17%  [unknown]  [unknown] (209 bytes)
>   2.47%  [unknown]  [unknown] (71 bytes)
>   2.12%  [unknown]  [unknown] (28 bytes)
>   2.04%  [unknown]  [unknown] (28 bytes)
>   1.63%  [unknown]  [unknown] (170 bytes)
>   0.95%  [unknown]  [unknown] (86 bytes)
>   0.89%  [unknown]  [unknown] (5 bytes)
>   0.83%  [unknown]  [unknown] (127 bytes)
>   0.81%  [unknown]  [unknown] (0 bytes)
>   0.55%  [unknown]  [unknown] (46 bytes)
>   0.44%  [unknown]  [unknown] (71 bytes)
>   0.41%  [unknown]  [unknown] (257 bytes)
>   2.91%  <...other 73 warm regions...>
> ............................................................
> ........................................
>  99.99%  <totals>
>
> ....[Hottest Methods (after inlining)]....................
> ..........................................
>  99.99%  [unknown]  [unknown]
> ............................................................
> ........................................
>  99.99%  <totals>
>
> ....[Distribution by Source].......................
> .................................................
>  99.99%  [unknown]
> ............................................................
> ........................................
>  99.99%  <totals>
>
>
>
> # Run complete. Total time: 00:00:18
>
> Benchmark                                          (implementation)
> (readRatio)  (tableSize)   Mode  Cnt         Score         Error  Units
> ConcurrentMapThroughput.randomGetPutRemove       NonBlockingHashMap
>      50       100000  thrpt    6  22470630.498 ± 3730613.043  ops/s
> ConcurrentMapThroughput.randomGetPutRemove:·asm  NonBlockingHashMap
>      50       100000  thrpt                NaN                  ---
> ConcurrentMapThroughput.randomGetPutRemove        ConcurrentHashMap
>      50       100000  thrpt    6  23411000.106 ± 1960758.197  ops/s
> ConcurrentMapThroughput.randomGetPutRemove:·asm   ConcurrentHashMap
>      50       100000  thrpt                NaN                  ---
>
> On 17 January 2018 at 07:20, Aleksey Shipilev <shade at redhat.com> wrote:
>
>> On 01/14/2018 04:24 PM, Vsevolod Tolstopyatov wrote:
>> > I have limited access to different versions of Mac OS X, but it seems
>> that in some minor updates
>> > DTrace works with SIP enabled.
>> > So as solution I'd suggest to check SIP status on profiler start (via
>> "csrutil status") and print
>> > warning if it's enabled or just clarify it in javadoc. It's up to
>> Alexey to decide what approach is
>> > preferable in JMH
>>
>> So, perf* profiler print warning messages when then number of samples is
>> suspiciously low. I think
>> dtraceasm profiler should do the same, and clearly say what the user is
>> supposed to do:
>>
>>  WARNING: The perf event count is suspiciously low (" + sum + "). The
>> performance data might be
>>  inaccurate or misleading. Try to do the profiling again, or tune up the
>> sampling frequency.
>>  With some profilers on Mac OS X, System Integrity Protection (SIP) may
>> prevent profiling.
>>  In such case, temporarily disabling SIP with 'csrutil disable' might
>> help.
>>
>> I'll add this to the patch myself.
>>
>> I can push this without my own testing, hoping that external people
>> validated this. OpenJDK rules
>> require the patch to be hosted on OpenJDK infra to get accepted, so,
>> Vsevolod, can you please post
>> the recent version of the patch inline here?
>>
>> Thanks
>> -Aleksey
>>
>>
>>
>