[Samba] Samba - XP performance problem

[Jeremy Allison]

On Wed, Aug 10, 2005 at 11:05:06AM +0200, David Beck wrote:
> Thank you for the suggestion. I'll keep the info for reference.
> 
> Followup for the performance issue:
> 
> The trace shows that the conversation changes right after the "trans2: 
> query file info internal" stage, so I looked into the samba code at this 
> file:
> 
> http://websvn.samba.org/cgi-bin/viewcvs.cgi/branches/SAMBA_3_0/source/smbd/trans2.c?rev=8959&view=markup
> 
> 		case SMB_FILE_INTERNAL_INFORMATION:
> 			/* This should be an index number - looks like
> 			   dev/ino to me :-) 
> 
> 			   I think this causes us to fail the IFSKIT
> 			   BasicFileInformationTest. -tpot */
> 
> 			DEBUG(10,("call_trans2qfilepathinfo: 
> 			SMB_FILE_INTERNAL_INFORMATION\n"));
> 			SIVAL(pdata,0,sbuf.st_dev);
> 			SIVAL(pdata,4,sbuf.st_ino);
> 			data_size = 8;
> 			break;
> 
> The comment speaks for itself. I suspect the 8 byte here contains some 
> magic that makes XP behaves as I found.
> 
> I made an other experiment: I turned off the oplock support ("Oplocks = 
> No") and this made XP behave like if it was talking to a Windows server.
> No extra tran2 calls and 1 byte writes. The performance got better 
> because the slowdowns disappeared, but it was still slower compared to 
> the windows machine.

Ok, I'm using the "disk test" part of www.passmark.com and can reproduce
the "1 byte write every 64k followed by a qfilinfo" call against Samba,
latest SVN code - but it also does the same against my Windows 2003 SP1
server....

BTW: - just using a cmd.exe prompt "COPY" command or using cut and
paste from a Windows explorer Windows doesn't reproduce this problem,
that writes completely normally.

What Windows server are you using ? It looks like a reported allocation
issue to me - but I'm still trying to understand what triggers this
behaviour in the client ?

Jeremy.