El Dilluns, 25 de maig de 2015, a les 20:32:52, Mark Gaiser va escriure: > Hi, > > A few days ago i started profiling and debugging the KIO SMB slave to > figure out why a simple task as listing a directory (in dolphin) is so > utterly slow. It's been like that for as long as i remember but never had > attempted to debug it before. > > Do this for example: > Mount a samba network share locally like so: > mount -t cifs //path/to/your/share /path/to/your/mount/ -o user=guest,guest > -v > > Now if you browse that folder in dolphin (the cifs mount) you get perfectly > fine performance. Listings work rapidly. > > If you browse to the exact same location using smb://path/to/your/share > you're welcomed by notably slower performance. I'm not talking about 0.1 > second vs 0.2, but rather numbers like ~1 second for cifs and ~5 seconds > for smb://.. You - as a user - will notice that difference. > > I know, i can just use cifs and be done with it. But i prefer to have a > good smb slave so i rather investigate this further. > > I've tried various things to profile this but i'm stuck.. I did make some > network profiles (using wireshark) to inspect the smb network packets.The > big difference i see there is that smb:// sends an ACK for everything it > receives. CIFS never sends any ACK (that i could find). > > I've tried putting valgrind over it with callgrind and that turned up one > weird behavior in listing a folder. Every single file request is being send > through SMBSlave::auth_smbc_get_data which in turn does "if ( > !checkCachedAuthentication( info ) )" which is a quite slow call! But > disabling that line (you can find it in kio_smb_auth.cpp line 100) doesn't > speed up directory listing notable. So while that is slow, that is not the > cause nor the fix. > > Starting a slave in debug mode and attaching a debugger to it also didn't > tell me anything useful either. > > I have no clue how to investigate this issue further. Would anyone > (preferably with knowledge of the SMB slave) be kind enough to provide some > help or pointers where i can find help to tackle this issue?
Have you tried smb command line utils like smbclient? Are they also slow or fast? Cheers, Albert > > Cheers, > Mark
