Hi Andre, On Thu, 5 Feb 2009 11:45:36 +0100, Andre Prendel wrote: > On Thu, Feb 05, 2009 at 10:53:34AM +0100, Jean Delvare wrote: > > On Thu, 5 Feb 2009 10:03:31 +0100, Andre Prendel wrote: > > > I assume there are no hidden files in the directory, right? That's the > > > reason why I have removed this from condition. > > > > I've never seen hidden files in sysfs except for sections > > in /sys/module. But the purpose of the original code was merely to skip > > "." and ".." anyway, not hidden files. > > At another place (sysfs_foreach_classdev()) there is a comment > explaining the condition. > > [...] > if (ent->d_name[0] == '.') /* skip hidden entries */ > continue; > [...] Indeed, but as I recall, the hidden entries we were worried about back then were just "." and "..". I don't expect it to make any difference anyway, as I doubt we'll ever have other hidden files or directories in class directories, nor do I expect non-directory (or link to directory) entries there. > > (...) > > If you really care about performance (and I guess that's the sole > > purpose of your patch) then it's faster to check for ent->d_type != > > DT_REG. > > Indeed. That's even better. > > > You can also move "name = ent->d_name" after this test to make > > the fast path even faster. > > This should just avoid needless work and maybe potential errors in > parsing unexpected directory names. I get the idea, and second it. > > Out of curiosity, did you actually measure any performance improvement > > with your patch? > > I didn't do a measurement. That wasn't the goal. You might want to ask valgrind about it (I certainly will, being curious.) > P.S. To become familiar with the whole code and getting a better > understanding how things work, I walk through the code. And if I found > something that I would do in a different way, I send a patch to you :) Sounds like a good plan, don't stop :) Care to send an updated patch? I'll be happy to apply it. -- Jean Delvare
