Re: kern/37025

["Martin S. Weber" <Ephaeton%gmx.net@localhost>]

The following reply was made to PR kern/37025; it has been noted by GNATS.

From: "Martin S. Weber" <Ephaeton%gmx.net@localhost>
To: gnats-bugs%gnats.netbsd.org@localhost
Cc: 
Subject: Re: kern/37025
Date: Mon, 1 Mar 2010 17:27:46 -0500

 Alright, it seems I prematurely jumped to conclusions here. I left
 the computer alone when it was still running tests with low
 blocksizes; with higher blocksizes the image changes.
 
 The following are results for reading and writing ~130MB of "random"
 data (a release.tar containing a set of i386 binary sets) to the
 samba share (read from or written to a local wapbl ffs). The server
 is something native windows -- the network a 100MBit. I don't have
 any control whatsoever over the server in case you wanna ask
 questions, although I might find one thing or another out. The
 client machine was a NetBSD 5.0_STABLE (GENERIC) #4: Tue Jan  5
 13:58:42 EST 2010
 
 Good news first: you'll see that mount_smbfs performs (nearly) en
 par with smbclient, if the blocksize is just high enough.
 
 writing:
 block \  block type & attempt
 size   \   obs#1   bs#1     obs#2  bs#2    obs#3    bs#3
 --------\-----------------------------------------------
 1/2 kiB |  694kB   800kB   866kB   910kB   935kB  1021kB
 1   kiB | 1272kB  1306kB  1553kB   280kB  1493kB   444kB
 2   kiB | 2666kB  2760kB  2952kB  2972kB  2719kB  2877kB
 4   kiB | 3760kB  3668kB  4593kB  4599kB  4647kB  4093kB
 8   kiB | 4892kB  5040kB  6350kB  6014kB  6232kB  6200kB
 16  kiB | 6675kB  7112kB  7913kB  7970kB  7850kB  7944kB
 32  kiB | 8338kB  8459kB  8977kB  9189kB  9035kB  9148kB
 64  kiB | 8664kB  8753kB  9203kB  9252kB  9275kB  9336kB
 --------+-----------------------------------------------
 default | 1022kB (at about the time of bs#3 measurement)
 smbcl   |  #1: 8595kB     #2: 9198kB       #3: 9264kB
 
 reading:
 block \  block type & attempt
 size   \   ibs#1   bs#1    ibs#2  bs#2     ibs#3    bs#3
 --------\-----------------------------------------------
 1/2 kiB |  759kB   736kB   944kB  944kB  1049kB   328kB
 1   kiB | 1319kB  1389kB  1567kB 1813kB  1532kB  1537kB
 2   kiB | 2281kB  2083kB  2952kB 3114kB  2874kB  3007kB
 4   kiB | 3285kB  3655kB  4487kB 4798kB  3609kB  4503kB
 8   kiB | 4890kB  5196kB  5870kB 6468kB  5974kB  6358kB
 16  kiB | 6286kB  7178kB  7268kB 7914kB  7415kB  7955kB
 32  kiB | 7907kB  8611kB  8513kB 9495kB  8504kB  9621kB
 64  kiB | 7968kB  8843kB  8584kB 9536kB  9275kB  9336kB
 --------+-----------------------------------------------
 default | 1070kB (at about the time of bs#3 measurement)
 smbcl   |   #1: 9253kB     #2: 9845kB      #3: 9896kB
 
 For the bad news:
 - I had to keep some while :; do ls ; sleep 5; done running to have
 access to the share every now and then, without it, the transfers
 will stall pretty quickly.  
 
 - Even with that, sometimes the ls itself was stuck (in tstile)
 while the dd was stuck in smbwrq (at least the one case where I
 thought of checking dd's state). Things wouldn't move without me
 doing ANOTHER ls on the samba share. Then, both the ls would
 immediately do its job as would the dd pick up pace again (as seen
 on xosview's NET traffic display).
 
 - I didn't notice all of these "stuck" situations at once, that's
 where the worst results in above tables come from : reading (1/2
 kiB, bs#3), writing (1 kiB, bs#3)
 
 - I'm not satisfied yet with the results and will do further
 measurements (cp specifically although I doubt it will differ
 from the dd-default case at least for writing)
 
 For completeness: following outlines the measurement method:
 
 ==========
 #! /bin/ksh
 date
 bs=512
 while [ $bs -lt 66000 ]
 do 
        echo "dd writing"
        for block in obs bs
        do 
                echo -n "bs:$bs block:$block "
                dd if=release.tar of=$SMBSHARE/release.tar $block=$bs 
        done 
 
        echo "dd reading"
        for block in ibs bs
        do 
                echo -n "bs:$bs block:$block "
                dd if=$SMBSHARE/release.tar of=release.tar $block=$bs 
        done 
 
        bs=$(($bs * 2))
 done
 
 echo "smbclient reading"
 smbclient -c "cd $SMBHOME/$SMBSHARE; get release.tar" \
  -I $SMBSRV -W $WRK -U $USR //$USR@$SMB/$SHR $password
 
 echo "smbclient writing"
 smbclient -c "cd $SMBHOME/$SMBSHARE; put release.tar" \
  -I $SMBSRV -W $WRK -U $USR //$USR@$SMB/$SHR $password
 
 date
 ==========
 
 If you see a systematic/fundamental flaw in the above, please
 let me know.
 
 Regards,
 -Martin