Differences for win32 versus Linux open() performance

[John Arbash Meinel]

-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1

I'm working on profiling initial commit performance. I ended up creating
a tree that has all the files of mysql, but without any content. It
still took ~9s to commit.

So I started digging further, and I found that *just*:
   open(fname, 'rb').close()

For 7k files takes 3.6s on win32. On a much older linux sytem, it only
takes 0.6s. I assume this is the issues with opening a file locks its
path, etc.

Anyway, I was pretty shocked to see the pure overhead of open() be so
high. Though it also explains why the time of 'bzr selftest' is so much
slower.

Note, I even tried to go to os.open() and win32file.CreateFile to see if
it was possible to be faster. (nope)

I wasn't even able to cheat with the chdir() tricks we used for readdir.

John
=:->

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.9 (Cygwin)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org

iEYEARECAAYFAkopdb0ACgkQJdeBCYSNAAMx/gCffaxXZIcwd1aU3FulT4UN78DK
OcoAnAnrGrFLXZ5oeAeARWq3DtG/blwT
=9fO3
-----END PGP SIGNATURE-----