Skip to main content
[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [List Home]
RE: [cdt-dev] CPreprocessor 
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.

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


> -----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
> > > > https://dev.eclipse.org/mailman/listinfo/cdt-dev
> > > >
> > > _______________________________________________
> > > cdt-dev mailing list
> > > cdt-dev@xxxxxxxxxxx
> > > https://dev.eclipse.org/mailman/listinfo/cdt-dev
> > _______________________________________________
> > cdt-dev mailing list
> > cdt-dev@xxxxxxxxxxx
> > https://dev.eclipse.org/mailman/listinfo/cdt-dev
> >
> >
> > _______________________________________________
> > cdt-dev mailing list
> > cdt-dev@xxxxxxxxxxx
> > https://dev.eclipse.org/mailman/listinfo/cdt-dev
> >
> _______________________________________________
> cdt-dev mailing list
> cdt-dev@xxxxxxxxxxx
> https://dev.eclipse.org/mailman/listinfo/cdt-dev

Back to the top