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Re: [cdt-dev] CPreprocessor
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On Nov 15, 2007 8:22 AM, Doug Schaefer <DSchaefer@xxxxxxx> wrote:
> I swear it's because you have less method calls. I know you guys don't
> believe me :)
>
> And I've ran into this before. When I switch from Strings to char[]s in the
> scanner, I got a savings of around 25%. But you'll never find a profiling
> tool that'll tell you that you were 25% of your time in String methods.
Performance improvement from using char[] instead of String most
likely comes from the garbage collector. char[] is a single object
while String is two (itself plus the internal char[]).
> If it's not the expense of Java method calls, then you are running into
> caching or swapping issues. My Firefox test was done on a 512MB RAM machine.
> If your fixes enabled the parsing to run in less physical memory, that could
> explain why I got a bigger improvement.
>
> Doug Schaefer, QNX Software Systems
> Eclipse CDT Project Lead, http://cdtdoug.blogspot.com
-sergey
> > -----Original Message-----
> > From: cdt-dev-bounces@xxxxxxxxxxx [mailto:cdt-dev-bounces@xxxxxxxxxxx] On
> > Behalf Of Schorn, Markus
> > Sent: Thursday, November 15, 2007 8:23 AM
> > To: CDT General developers list.
>
> > Cc: cdt-dev-bounces@xxxxxxxxxxx
> > Subject: RE: [cdt-dev] CPreprocessor
> >
> > Hmm, this becomes confusing. I guess my setup is different (firefox on
> > windows using cygwin).
> >
> > Without having a proof, I claim that the new location map is faster
> > than the old one, because it is simpler. I never though that it could
> > make
> > up for the performance loss in the lexer, though.
> >
> > I also see a slight improvement in the problem percentage (firefox: 6.83
> > -> 6.75), which may influence the performance (in either way).
> >
> > All together, it looks like we can digest the 25% performance drop on
> > the lexer side and index firefox in less than 15min, that's what I am
> > happy about.
> >
> > Here are my firefox numbers:
> >
> > DOMScanner:
> > PDOMFastIndexerTask firefox-2.0 (2521 sources, 4108 headers)
> > PDOMFastIndexerTask Options: parseAllFiles=false,skipReferences=false,
> > skipTypeReferences=true.
> > PDOMFastIndexerTask Timings: 668000 total, 210188 parser, 293708
> > resolution, 117220 index update.
> > PDOMFastIndexerTask Errors: 0 unresolved includes, 0 unexpected errors.
> > PDOMFastIndexerTask Result: 579947 declarations, 1497415 references,
> > 152186(6,83%) problems.
> > PDOMFastIndexerTask Cache[30mb]: 834387236 hits, 121874(0,0146%) misses.
> >
> >
> > CPreprocessor:
> > PDOMFastIndexerTask firefox-2.0 (2521 sources, 4108 headers)
> > PDOMFastIndexerTask Options: parseAllFiles=false,skipReferences=false,
> > skipTypeReferences=true.
> > PDOMFastIndexerTask Timings: 667513 total, 215723 parser, 304567
> > resolution, 125964 index update.
> > PDOMFastIndexerTask Errors: 0 unresolved includes, 0 unexpected errors.
> > PDOMFastIndexerTask Result: 603145 declarations, 1497095 references,
> > 152045(6,75%) problems.
> > PDOMFastIndexerTask Cache[30mb]: 918390081 hits, 132025(0,0144%) misses.
> >
> > Markus.
> >
> > > -----Original Message-----
> > > From: cdt-dev-bounces@xxxxxxxxxxx
> > > [mailto:cdt-dev-bounces@xxxxxxxxxxx] On Behalf Of Mike Kucera
> > > Sent: Mittwoch, 14. November 2007 20:07
> > > To: CDT General developers list.
> > > Cc: CDT General developers list.; cdt-dev-bounces@xxxxxxxxxxx
> > > Subject: RE: [cdt-dev] CPreprocessor
> > > Importance: Low
> > >
> > > Those are great numbers.
> > >
> > > Markus, I'm curious to know where you think the performance
> > > gain is coming
> > > from. Is it the new location map?
> > >
> > >
> > > Mike Kucera
> > > Software Developer
> > > IBM CDT Team, Toronto
> > > mkucera@xxxxxxxxxx
> > >
> > >
> > >
> > >
> > >
> > > Doug Schaefer
> > >
> > > <DSchaefer@xxxxxx
> > >
> > > m>
> > > To
> > > Sent by: "CDT General
> > > developers list."
> > > cdt-dev-bounces@e <cdt-dev@xxxxxxxxxxx>
> > >
> > > clipse.org
> > > cc
> > >
> > >
> > >
> > > Subject
> > > 11/14/2007 01:39 RE: [cdt-dev]
> > > CPreprocessor
> > > PM
> > >
> > >
> > >
> > >
> > >
> > > Please respond to
> > >
> > > "CDT General
> > >
> > > developers list."
> > >
> > > <cdt-dev@eclipse.
> > >
> > > org>
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > >
> > > I don't know. I'm showing a 10-20% improvement with my Firefox tests.
> > >
> > > Great work Markus, thanks!
> > >
> > > Doug Schaefer, QNX Software Systems
> > > Eclipse CDT Project Lead, http://cdtdoug.blogspot.com
> > >
> > >
> > > > -----Original Message-----
> > > > From: cdt-dev-bounces@xxxxxxxxxxx
> > > [mailto:cdt-dev-bounces@xxxxxxxxxxx] On
> > > > Behalf Of Schorn, Markus
> > > > Sent: Wednesday, November 14, 2007 5:03 AM
> > > > To: CDT General developers list.
> > > > Subject: RE: [cdt-dev] CPreprocessor
> > > >
> > > > I have rerun the tests over night and the result is less
> > > spectacular,
> > > > you can expect improvements from 0% to 4%. Probably the
> > > first results
> > > > were influenced by some other load on my machine, so I need to reset
> > > > expectations:
> > > >
> > > > In detail ACE -6%, TAO -0%, Linux Kernel -5%, Firefox -0%.
> > > > I am happy with the numbers, anyways. I am changing CDT to use
> > > > CPreprocessor.
> > > > I'll keep Scanner2 around until the end of the year, but plan on
> > > > removing it,
> > > > to get started on stuff that depends on the preprocessor.
> > > > Markus.
> > > >
> > > > > -----Original Message-----
> > > > > From: cdt-dev-bounces@xxxxxxxxxxx
> > > > > [mailto:cdt-dev-bounces@xxxxxxxxxxx] On Behalf Of Schorn, Markus
> > > > > Sent: Dienstag, 13. November 2007 16:13
> > > > > To: CDT General developers list.
> > > > > Subject: [cdt-dev] CPreprocessor
> > > > > Importance: Low
> > > > >
> > > > > Hi,
> > > > > the performance tests for the indexer using the CPreprocessor went
> > > > > really good, I see an overall performance improvement of
> > > 5-10% (tested
> > > > > with ACE, TAO, Linux Kernel and Firefox).
> > > > >
> > > > > Given that I want to make the CPreprocessor the default
> > > rather sooner
> > > > > than later and support Scanner2 with -Dscanner=Scanner2
> > > for a while.
> > > > > Does anyone object to that?
> > > > > Markus.
> > > > >
> > > > > https://bugs.eclipse.org/bugs/show_bug.cgi?id=205272
> > > > > _______________________________________________
> > > > > cdt-dev mailing list
> > > > > cdt-dev@xxxxxxxxxxx
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> > > > >
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