Bug 310811

Summary:

[perfs] Big regression on FullSourceWorkspaceFormatterTests#testFormatDefaultBigFile()

Product:

[Eclipse Project] JDT

Reporter:

Frederic Fusier <frederic_fusier>

Component:

Core

Assignee:

Frederic Fusier <frederic_fusier>

Status:

VERIFIED FIXED

QA Contact:

Severity:

major

Priority:

CC:

jarthana, Olivier_Thomann, satyam.kandula, sergey.yevtushenko

Version:

3.6

Flags:

Olivier_Thomann: review+

Target Milestone:

3.6 RC1

Hardware:

OS:

Windows XP

Whiteboard:

Bug Depends on:

Bug Blocks:

286955

Attachments:

Description	Flags
Proposed patch	none

Description Frederic Fusier

2010-04-28 09:07:15 EDT

Verifying performances for 3.6M7 candidates builds, I observed a big regression on formatter tests FullSourceWorkspaceFormatterTests#testFormatDefaultBigFile(): around -30%!

Note that there's a similar regression on testFormatDefault() but less visible.

Comment 1 Frederic Fusier

2010-04-28 09:08:55 EDT

99.99% chance that this regression is a consequence of the fix for bug 59891...

I see if something can be done for RC1...

Comment 2 Frederic Fusier

2010-05-03 15:48:01 EDT

Created attachment 166863 [details]
Proposed patch

This patch adds to performance improvements:
1) It disable the fix for bug 59891 in the case when there are a string concatenation inside the message send. In the peculiar case of the formatter perf test showing the regression, there are tons of this with complex string concatenation and the formatter can raise until 280 AlignmentException before getting a formatted string... Relaxing the previous fix for that does not have any impact on the massive formatter tests which confirms that the performance was really a corner case!
2) It tries to reduce the instanciation of StringBuffer to avoid unnecessary time and garbaged memory consuming.

Point 1) reduce the regression of around 75% and 2) around 25%, which means that with this patch we get back to M6 performance levels for our peculiar perf test case.

Comment 3 Frederic Fusier

2010-05-03 15:50:04 EDT

Olivier, please review, thanks

Comment 4 Olivier Thomann

2010-05-03 21:47:18 EDT

+1

Comment 5 Frederic Fusier

2010-05-04 05:11:44 EDT

(In reply to comment #2)
> Created an attachment (id=166863) [details]
> Proposed patch
> 
Released for 3.6RC1 in HEAD stream

Comment 6 Satyam Kandula

2010-05-17 06:12:55 EDT

There is still 8% performance degradation but it is much better than 30%. Hence verifying. 

Verified for 3.6RC1 using build I20100513-150

Comment 7 Jay Arthanareeswaran

2010-05-17 06:15:44 EDT

Verified.

Comment 8 Frederic Fusier

2010-12-27 03:50:42 EST

*** Bug 230188 has been marked as a duplicate of this bug. ***