[petsc-dev] slow "ar Scq" on cygwin

Thu Jun 28 21:39:00 CDT 2012

On Thu, 28 Jun 2012, Chetan Jhurani wrote:

> > Look. It does not do that. Ever. In any universe. I don't know what you think you are doing,
> 
> > but it is definitely not what you wrote. Look at the code. It can't do that.
> 
>  
> 
> I don't think you understand what your code is doing in a new
> 
> environment of the same universe.
> 
>  
> 
> It works fine on Linux with the steps you had given.
> 
> But on the cygwin side, no dependency files like
> 
> ./lib/libpetsc-obj/adaptbasic.d are created. I found this after
> 
> running the python build on Linux (I didn't know before this
> 
> where the dependencies were stored).
> 
>  
> 
> Here is some debug info in the python code:
> 
>  
> 
> In the buildLibraries function on the Linux box (when building in the second step)
> 
>  
> 
>   self.sourceDatabase =  DirectedGraph with 1172 vertices and 21894 edges
> 
>  
> 
> However, on the cygwin side (again, when building the second time)
> 
>  
> 
>  self.sourceDatabase =  <builder.NullSourceDatabase object at 0xffd833ac>
> 
>  
> 
> So of course it is totalRebuild = true on cygwin.

Hm - eventhough you added 'argparse.py' to python-2.6 on cygwin to get
builder.py working - perhaps Matt is using some other python-2.7
feature - and thats causing this difference?

Satish

> 
>  
> 
> I don't mind extra debugging on cygwin/Windows before reporting issues
> 
> since I know the petsc project has many other priorities. But a few useful
> 
> debugging pointers will be serve both of us better.
> 
>  
> 
> Chetan
> 
>  
> 
>  
> 
>  
> 
>  
> 
> From: petsc-dev-bounces at mcs.anl.gov [mailto:petsc-dev-bounces at mcs.anl.gov] On Behalf Of Matthew Knepley
> Sent: Thursday, June 28, 2012 6:00 PM
> To: For users of the development version of PETSc
> Subject: Re: [petsc-dev] slow "ar Scq" on cygwin
> 
>  
> 
> On Thu, Jun 28, 2012 at 4:49 PM, Chetan Jhurani <chetan.jhurani at gmail.com> wrote:
> 
> > > $ PETSC_DIR=/cygdrive/d/petsc-dev-2012-06-26 PETSC_ARCH=test_8 ./config/builder.py
> > > (The same happens (existing .o are deleted) if ./config/builder2.py build is used)
> 
> > This is not what I wrote. You used builder.py, which is python 2.4 compatible, but has to do everything without options,
> > so yes it deletes all the objects and rebuilds everything. That is why I did not suggest you use it.
> 
> > I said to use builder2.py, which does proper dependency tracking.
> 
>  
> 
> That is what I used and I mentioned it above. I've tried both separately.
> 
>  
> 
> Both give the same result that libpetsc.lib is not created.  And
> 
> whether I use builder.py or builder2.py, the existing objects
> 
> files are deleted in the second build. I did not call for a cleanup.
> 
>  
> 
> Look. It does not do that. Ever. In any universe. I don't know what you think you are doing,
> 
> but it is definitely not what you wrote. Look at the code. It can't do that.
> 
>  
> 
>   matt
> 
>  
> 
> To be sure, I tried the whole thing in a new ARCH with a fresh
> 
> configure step, and this time builder.py was not used at all (by me)
> 
> but it led to the same issues with builder2.py.
> 
>  
> 
> I understand that this is not the most used platform, so let me
> 
> know if I can be of help.  And I forgot to mention that the
> 
> python build was 4-5 times faster than "ar" based build and
> 
> that's great...
> 
>  
> 
> Chetan
> 
>  
> 
>  
> 
>  
> 
>  
> 
>  
> 
> From: petsc-dev-bounces at mcs.anl.gov [mailto:petsc-dev-bounces at mcs.anl.gov] On Behalf Of Matthew Knepley
> Sent: Thursday, June 28, 2012 3:21 PM
> To: For users of the development version of PETSc
> Subject: Re: [petsc-dev] slow "ar Scq" on cygwin
> 
>  
> 
> On Thu, Jun 28, 2012 at 4:10 PM, Chetan Jhurani <chetan.jhurani at gmail.com> wrote:
> 
> Matt,
> 
>  
> 
> I was surprised too on both counts. Couldn't find any libpetsc.lib after the python build
> 
> and I did not run "clean" in between that could have deleted the .o files.
> 
>  
> 
> Here's one more try below to show it.
> 
>  
> 
> $ ls test_8/lib/
> 
> libpetsc-obj
> 
>  
> 
> $ ls test_8/lib/libpetsc-obj/ | wc -l
> 
> 560
> 
>  
> 
> $ PETSC_DIR=/cygdrive/d/petsc-dev-2012-06-26 PETSC_ARCH=test_8 ./config/builder.py
> 
> (The same happens (existing .o are deleted) if ./config/builder2.py build is used)
> 
>  
> 
> This is not what I wrote. You used builder.py, which is python 2.4 compatible, but has to do everything without options,
> 
> so yes it deletes all the objects and rebuilds everything. That is why I did not suggest you use it.
> 
>  
> 
> I said to use builder2.py, which does proper dependency tracking.
> 
>  
> 
>    Matt
> 
>  
> 
>  
> 
> Rebuilding Dependencies
> 
> Building in /cygdrive/d/petsc-dev-2012-06-26/src/sys
> 
> Building in /cygdrive/d/petsc-dev-2012-06-26/src/sys/bag
> 
> Building in /cygdrive/d/petsc-dev-2012-06-26/src/sys/comm
> 
> Building in /cygdrive/d/petsc-dev-2012-06-26/src/sys/dll
> 
>  
> 
> I stopped the build using control-c.  It would have deleted all files first.
> 
>  
> 
> Traceback (most recent call last):
> 
>   File "./config/builder.py", line 1534, in <module>
> 
>     PETScMaker().run()
> 
>   File "./config/builder.py", line 1526, in run
> 
>     if self.buildLibraries('libpetsc', self.rootDir):
> 
>   File "./config/builder.py", line 1331, in buildLibraries
> 
>     objects += self.buildDir(root, files, objDir)
> 
>   File "./config/builder.py", line 1251, in buildDir
> 
>     objects.extend(getattr(self, 'compile'+language)(sourceMap[language], objDir))
> 
>   File "./config/builder.py", line 1025, in compileC
> 
>     return self.compile(self.configInfo.languages.clanguage, source, objDir)
> 
>   File "./config/builder.py", line 1012, in compile
> 
>     (output, error, status) = self.executeShellCommand(cmd, checkCommand = noCheckCommand, log=self.log)
> 
>   File "/cygdrive/d/petsc-dev-2012-06-26/config/BuildSystem/script.py", line 254, in executeShellCommand
> 
>     (output, error, status) = runInShell(command, log, cwd)
> 
>   File "/cygdrive/d/petsc-dev-2012-06-26/config/BuildSystem/script.py", line 243, in runInShell
> 
>     thread.join(timeout)
> 
>   File "/usr/lib/python2.6/threading.py", line 655, in join
> 
>     self.__block.wait(delay)
> 
>   File "/usr/lib/python2.6/threading.py", line 258, in wait
> 
>     _sleep(delay)
> 
> KeyboardInterrupt
> 
>  
> 
> $ ls test_8/lib/libpetsc-obj/
> 
> bag.o
> 
>  
> 
> All the previous .o were deleted.  Perhaps I'm not doing something right?
> 
>  
> 
> Chetan
> 
>  
> 
>  
> 
> From: petsc-dev-bounces at mcs.anl.gov [mailto:petsc-dev-bounces at mcs.anl.gov] On Behalf Of Matthew Knepley
> Sent: Thursday, June 28, 2012 2:46 PM
> To: For users of the development version of PETSc
> Subject: Re: [petsc-dev] slow "ar Scq" on cygwin
> 
>  
> 
> On Thu, Jun 28, 2012 at 3:31 PM, Chetan Jhurani <chetan.jhurani at gmail.com> wrote:
> 
> Thanks Matt, Satish.  A few issues though.
> 
>  
> 
> Like you said, the latest cygwin has python 2.6.8 which
> 
> does not have argparse.  When I place the following
> 
> in path http://argparse.googlecode.com/svn/trunk/argparse.py
> 
> I can run the python build with 2.6.8.
> 
>  
> 
> However, the "ar" based build had worked fine and the python
> 
> based build fails for these two files.
> 
>  
> 
>   src/snes/impls/MULTIB~1/multiblock.c
> 
>   src/snes/impls/vi/rsaug/virsaug.c
> 
>  
> 
> Yep, it fails, but the build succeeds, so no problem.
> 
>  
> 
> It looks like these two files were NOT compiled in the ar based
> 
> build. The two make.log files are attached.
> 
>  
> 
> One more question. I tried to run the python based build
> 
> the second time (after it was unsuccessful the first time)
> 
> and then it deleted all the previous .o files it had created in 
> 
> ARCH/lib/libpetsc-obj.  How can that be avoided?
> 
>  
> 
> It does not do that unless you run 'clean'.
> 
>  
> 
>    Matt
> 
>  
> 
> Chetan
> 
>  
> 
>  
> 
> From: petsc-dev-bounces at mcs.anl.gov [mailto:petsc-dev-bounces at mcs.anl.gov] On Behalf Of Matthew Knepley
> Sent: Thursday, June 28, 2012 1:35 PM
> To: For users of the development version of PETSc
> Subject: Re: [petsc-dev] slow "ar Scq" on cygwin
> 
>  
> 
> On Thu, Jun 28, 2012 at 2:23 PM, Chetan Jhurani <chetan.jhurani at gmail.com> wrote:
> 
> Hi devs,
> 
> Is there a way to avoid running the archiver (ar)
> every time a petsc directory is compiled?
> 
> The reason I'm asking this is that when libpetsc.lib
> becomes large enough (say 100MB+, esp. for debug build),
> "ar Sqc" on cygwin takes very long in each directory.
> Depending on OS caching, very long can be 10 seconds per
> PETSc directory just to run ar.
> 
> It creates a new temp file from scratch, puts stuff from
> libpetsc.lib and new stuff in it and then renames the
> temp file.  As you can imagine, the compilation process is
> fast in the beginning but crawls by the end.  I've seen
> the same IO sequence on Linux (with Sqc flags to ar), but
> since cygwin IO is slower the effect is more clearly visible.
> Building within a ramdisk leads to 25% faster compilation
> but it was more of a curiosity.
> 
>  
> 
> Build with Python. It never uses antique things like ar :)
> 
>  
> 
>   python2.7 ./config/builder2.py build
> 
>  
> 
>      Matt
> 
>  
> 
> 
> Chetan
> 
> 
> 
> 
> 
>  
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> 