Re: Running benchmarks/suite1 on Windows

2011/6/21 Daniel Klíma <danklima_at_gmail.com>:
> 2011/6/21 Johan Corveleyn <jcorvel_at_gmail.com>:
>> Hi,
>>
>> I managed to get the benchmark 'suite1' (tools/dev/benchmarks/suite1,
>> which is used for the automated benchmarks [svnbench] on svn-qavm)
>> running on Windows. I did that by translating the 'run' script (bash)
>> to a Windows "batch" script (I'm not much of a "batch" programmer, but
>> with some trial and error, and the help of google ;-) ...).
>>
>> I've put the run.bat in attachment here (just strip the .txt
>> extension). I'll commit it tonight (don't have access right now), but
>> some extra eyes in the meantime can't hurt :-).
>>
>> There is one annoying issue remaining with the run script for Windows
>> (or the benchmark in general): I get an error when running the 100x1
>> tests (100 directory levels deep). I reduced it to 50x1, but still get
>> the error. It's probably some "max path component" or "max path
>> length" limit on Windows/NTFS that's causing this. Maybe some of the
>> Windows-devs knows how to work around this? Or should I reduce that
>> test to 25x1?
>>
> ...
>>  File "C:\research\svn\client_build\trunk\tools\dev\benchmarks\suite1\benchmark.py",
>> line 247, in create_tree
>>    create_tree(dn, levels - 1, spread)
>>  File "C:\research\svn\client_build\trunk\tools\dev\benchmarks\suite1\benchmark.py",
>> line 240, in create_tree
>>    f = open(fn, 'w')
>> IOError: [Errno 2] No such file or directory:
>> 'c:\\docume~1\\user\\locals~1\\temp\\tmpmddeli\\wc\\trunk\\dir_2\\dir_4\\d
>> ir_6\\dir_8\\dir_10\\dir_12\\dir_14\\dir_16\\dir_18\\dir_20\\dir_22\\dir_24\\dir_26\\dir_28\\dir_30\\dir_32\\dir_34\\dir
>> _36\\dir_38\\dir_40\\dir_42\\dir_44\\dir_46\\dir_48\\dir_50\\dir_52\\dir_54\\dir_56\\dir_58\\file_59'
>> ]]]
>>
>> For the rest it runs fine. Below are some results (only the 5x5 and
>> 1x100) from comparing trunk_at_1137727 with 1.6.17 (SlikSVN binary) on
>> Windows XP (32-bit) with local disk, with Antivirus disabled.
>>
>> Note that it took a *huge* time to run, even without the 100x1 tests
>> (~ 7 hours). I guess that shows how slow my machine really is ;-),
>> especially with 1.6. The performance improvements are definitely great
>> though (especially 'update', which is 80% faster with trunk! And also
>> 'commit', with is down almost 60%).
> ...
>>
>> --
>> Johan
>>
> Hello.
>
> Max_Path is 256 chars excluding drive part. Max path for unicode
> version of API is 32,767 when using path with "\\?\" style. I think
> cmd should be able to work with \\?\ .
>
> Ref: http://msdn.microsoft.com/en-us/library/aa365247(VS.85).aspx
> (Naming Files, Paths, and Namespaces section: Maximum Path Length
> Limitation)

Thanks, Daniel. That explains it.

But unfortunately, the error happens inside the python script
benchmark.py (in tools/dev/benchmarks/suite1), and I haven't found a
way to avoid it. I've experimented a bit with pre-pending the path
with "\\\\?\\" (which was also suggested at the end of this python
issue: [1]), but it didn't help.

I'll commit the Windows variant of the run script (run.bat) for now
with a maximum "levels" of 25, which means it usually won't exceed the
maximum path length. Maybe someone else can enhance it later (and/or
benchmark.py) to enable benchmarks for even deeper working copies on
Windows ...

-- 
Johan
[1] http://bugs.python.org/issue542314