locking issues

[Romeril, Alan]

Hi Jeremy,
	Thanks for the quick response!  I've backed out my changes and added
these patches and yep the speed is there for me.  This drops my logon time
from 70 to 46 seconds everyone else's mileage may vary :)

Cheers,
Alan

-----Original Message-----
From: Jeremy Allison [mailto:jeremy at valinux.com]
Sent: 29 January 2001 22:45
To: Romeril, Alan
Cc: 'samba-technical at samba.org'; jeremy at valinux.com
Subject: Re: locking issues


"Romeril, Alan" wrote:
> 
> Hello All,
>         We've been struggling with slow logons of Win2K clients to Samba
> servers (2.0.7 and 2.2.0) and looking at Ethereal dumps of the session
> between the Client and Samba server there seemed to be big delays in
> responding to SMBntcreateX requests with SMBlockingX packets.  Looking
> through the oplock code there's a couple of these in smbd/oplock.c
> 
>     /*
>      * If we are sending an oplock break due to an SMB sent
>      * by our own client we ensure that we wait at leat
>      * lp_oplock_break_wait_time() milliseconds before sending
>      * the packet. Sending the packet sooner can break Win9x
>      * and has reported to cause problems on NT. JRA.
>      */
> 
>     wait_before_sending_break(local_request);
>     /* Prepare the SMBlockingX message. */
> 
>     prepare_break_message( outbuf, fsp, False);
>     send_smb(Client, outbuf);
> 
> Jeremy or anyone else what are the things that break in 95 and what are
the
> problems caused in NT4?

This was when we were trying various things to fix oplock break problem
reports. One of the MS server developers claimed that this was a problem for
win9x
clients - we coded it up based on their assurance that this was the correct
fix. However, we were not able to reliably reproduce the problem - but
the code got left in there.... (sorry).

> Looking at a Win2K to Win2K logon these packets are sent very quickly
after
> the SMBntcreateX request, and there are many more SMBntcreateX packets
that
> result in a SMBlockingX response than for an NT4 logon.  Where is this
> going?  I added this if statement to not wait before sending in both
> occurrences when dealing with Win2K clients.
> 
>     /*
>      * If we are sending an oplock break due to an SMB sent
>      * by our own client we ensure that we wait at leat
>      * lp_oplock_break_wait_time() milliseconds before sending
>      * the packet. Sending the packet sooner can break Win9x
>      * and has reported to cause problems on NT. JRA.
>      */
>     /*
>      * WIN2K seems happy to bang out these breaks quickly, so are we.
AR12.
>      */
>     if (get_remote_arch() != RA_WIN2K) {
>         wait_before_sending_break(local_request);
>     }
> 
>     /* Prepare the SMBlockingX message. */
> 
> The result of this is about a 50% speed up of domain logons from Win2K
> clients, some users get less, some (with bigger profiles) get more.  So it
> goes back to my question what happens to NT4 when these packets are sent
too
> fast?  I don't want to put code live that has a chance of destroying data
/
> crashing clients, but as Win2K seems to send them quickly, the code runs
> fine on a test server and the speed up is really needed I'd like others to
> take a look at this as well.

*VERY* interesting ! The default is 10ms. I could drop the
default to 0, and allow people having problems to up the
time....

Try this patch (I will commit this for 2.2 and HEAD).

----------------cut here-------------------------------
Index: param/loadparm.c
===================================================================
RCS file: /data/cvs/samba/source/param/loadparm.c,v
retrieving revision 1.251.2.19
diff -u -r1.251.2.19 loadparm.c
--- param/loadparm.c	2001/01/23 19:20:50	1.251.2.19
+++ param/loadparm.c	2001/01/30 00:30:18
@@ -1256,7 +1256,7 @@
 	Globals.bRestrictAnonymous = False;
 	Globals.map_to_guest = 0;	/* By Default, "Never" */
 	Globals.min_passwd_length = MINPASSWDLENGTH;	/* By Default, 5. */
-	Globals.oplock_break_wait_time = 10;	/* By Default, 10 msecs. */
+	Globals.oplock_break_wait_time = 0;	/* By Default, 0 msecs. */
 
 #ifdef WITH_LDAP
 	/* default values for ldap */
Index: smbd/oplock.c
===================================================================
RCS file: /data/cvs/samba/source/smbd/oplock.c,v
retrieving revision 1.43.4.2
diff -u -r1.43.4.2 oplock.c
--- smbd/oplock.c	2000/11/16 01:19:05	1.43.4.2
+++ smbd/oplock.c	2001/01/30 00:30:25
@@ -470,6 +470,9 @@
     struct timeval cur_tv;
     long wait_left = (long)lp_oplock_break_wait_time();
 
+	if (wait_left == 0)
+		return;
+
     GetTimeOfDay(&cur_tv);
 
     wait_left -= ((cur_tv.tv_sec - smb_last_time.tv_sec)*1000) +
----------------cut here-------------------------------

*EXCELLENT* detective work !

Jeremy.

-- 
--------------------------------------------------------
Buying an operating system without source is like buying
a self-assembly Space Shuttle with no instructions.
--------------------------------------------------------