More tweaks to perf script

More tweaks to perf script
Committed: https://code.google.com/p/dart/source/detail?r=10914

[Emily Fortuna, 2012-08-15 01:17:33]

Removing more evidence of frog, added a weighted distribution mechanism for
going back through revisions in time. This will be further fine tuned when we
have numerical runtime data.

[vsm, 2012-08-15 15:27:32]

https://chromiumcodereview.appspot.com/10836249/diff/4001/tools/testing/perf_...
File tools/testing/perf_testing/run_perf_tests.py (right):

https://chromiumcodereview.appspot.com/10836249/diff/4001/tools/testing/perf_...
tools/testing/perf_testing/run_perf_tests.py:904: revision_num =
int(search_for_revision(['git', 'svn', 'info']))
Nit: I'd fold the previous 4 lines into search_for_revision and call something
like:
  revision_num = search_for_revision(DART_REPO_LOC)
here.

https://chromiumcodereview.appspot.com/10836249/diff/4001/tools/testing/perf_...
tools/testing/perf_testing/run_perf_tests.py:921: if 10 - num_results < 2 and
num_results >= 0:
This looks fishy.  "10 - num_results < 2" is equivalent to "num_results > 8",
which makes the second part redundant.

[Emily Fortuna, 2012-08-15 22:10:10]

https://chromiumcodereview.appspot.com/10836249/diff/4001/tools/testing/perf_...
File tools/testing/perf_testing/run_perf_tests.py (right):

https://chromiumcodereview.appspot.com/10836249/diff/4001/tools/testing/perf_...
tools/testing/perf_testing/run_perf_tests.py:904: revision_num =
int(search_for_revision(['git', 'svn', 'info']))
On 2012/08/15 15:27:32, vsm wrote:
> Nit: I'd fold the previous 4 lines into search_for_revision and call something
> like:
>   revision_num = search_for_revision(DART_REPO_LOC)
> here. 

Done.

https://chromiumcodereview.appspot.com/10836249/diff/4001/tools/testing/perf_...
tools/testing/perf_testing/run_perf_tests.py:921: if 10 - num_results < 2 and
num_results >= 0:
On 2012/08/15 15:27:32, vsm wrote:
> This looks fishy.  "10 - num_results < 2" is equivalent to "num_results > 8",
> which makes the second part redundant.

num_results returns -1 if it has an error connecting and getting data, in which
case reruns = 10-(-1) ==> 11 which is not what we want! This handles the case if
it can't connect, it just runs two additional perf tests for good measure
(because if it can't connect, it's likely to not connect for a little bit, and I
figured running tests was better than sitting idle). I'll rewrite >=0 to != -1
so that situation is a little more obvious.

[vsm, 2012-08-16 00:20:21]

https://chromiumcodereview.appspot.com/10836249/diff/6001/tools/testing/perf_...
File tools/testing/perf_testing/run_perf_tests.py (right):

https://chromiumcodereview.appspot.com/10836249/diff/6001/tools/testing/perf_...
tools/testing/perf_testing/run_perf_tests.py:925: if 10 - num_results < 2 and
num_results != -1:
"if num_results > 8:" is more readable.  Also, a comment along the lines of: Run
at most two more times.

https://chromiumcodereview.appspot.com/10836249/diff/6001/tools/testing/perf_...
tools/testing/perf_testing/run_perf_tests.py:926: reruns = 10 - num_results
What happens if reruns is less than 0?

https://chromiumcodereview.appspot.com/10836249/diff/6001/tools/testing/perf_...
tools/testing/perf_testing/run_perf_tests.py:934: return False
Can you add a comment on what the return value means?

https://chromiumcodereview.appspot.com/10836249/diff/6001/tools/testing/perf_...
tools/testing/perf_testing/run_perf_tests.py:955: int(math.pow(10,
int(math.floor(math.log10(int(revision_num))))) + 1))
Can you add some comments here?  What is the intended range of rev?

If I plug in revision_num == 10000 and thousands == 9, I get an error executing
this last statement in python.

[Emily Fortuna, 2012-08-16 21:41:08]

whew! Cleaned up the "random-cl-selection" insanity.

https://chromiumcodereview.appspot.com/10836249/diff/6001/tools/testing/perf_...
File tools/testing/perf_testing/run_perf_tests.py (right):

https://chromiumcodereview.appspot.com/10836249/diff/6001/tools/testing/perf_...
tools/testing/perf_testing/run_perf_tests.py:925: if 10 - num_results < 2 and
num_results != -1:
On 2012/08/16 00:20:22, vsm wrote:
> "if num_results > 8:" is more readable.  Also, a comment along the lines of:
Run
> at most two more times.
> 

good point. fixed.

https://chromiumcodereview.appspot.com/10836249/diff/6001/tools/testing/perf_...
tools/testing/perf_testing/run_perf_tests.py:926: reruns = 10 - num_results
On 2012/08/16 00:20:22, vsm wrote:
> What happens if reruns is less than 0?
Fixed.

https://chromiumcodereview.appspot.com/10836249/diff/6001/tools/testing/perf_...
tools/testing/perf_testing/run_perf_tests.py:934: return False
On 2012/08/16 00:20:22, vsm wrote:
> Can you add a comment on what the return value means?

Done.

[vsm, 2012-08-16 22:58:08]

lgtm

https://chromiumcodereview.appspot.com/10836249/diff/12001/tools/testing/perf...
File tools/testing/perf_testing/run_perf_tests.py (right):

https://chromiumcodereview.appspot.com/10836249/diff/12001/tools/testing/perf...
tools/testing/perf_testing/run_perf_tests.py:960: hundreds = 1 + revision_num %
bucket_size
Nit: should be "ones" not "hundreds".  Or maybe "max_range".