irclog2html for #brlcad on 20070319

00:18.06 IriX64 err just noticed, never mind the index :) i screwup like that regularly.
00:25.50 *** join/#brlcad docelic (n=docelic@212.15.170.57)
01:04.32 *** join/#brlcad CIA-21 (i=cia@cia.navi.cx)
01:58.58 IriX64 what frequency? :)
02:00.11 Maloeran Perhaps to see if there's some bug left? I left it run with distributed processing on 3 boxes for about 36 hours, I'm hoping it's fine
02:40.15 CIA-21 BRL-CAD: 03brlcad * 10brlcad/src/external/EndgameFramework/Makefile.am: include the defs file so we get additional rules
02:41.07 CIA-21 BRL-CAD: 03brlcad * 10brlcad/misc/enigma/Makefile.am: stub rules so recursion completes cleanly
02:41.36 brlcad possibly
04:19.56 IriX64 Hah you may have another customer, the local mill has people watching my antics with brlcad.
07:03.53 *** join/#brlcad clock_ (i=clock@84-72-61-171.dclient.hispeed.ch)
08:24.41 *** join/#brlcad clock_ (n=clock@zux221-122-143.adsl.green.ch)
13:21.01 *** join/#brlcad Twingy (n=justin@74.92.144.217) [NETSPLIT VICTIM]
14:35.38 *** join/#brlcad clock_ (n=clock@zux221-122-143.adsl.green.ch)
15:20.43 *** join/#brlcad cad46 (n=5b1736b3@bz.bzflag.bz)
16:18.35 ``Erik and now I'm on vacation for a week, w00t :D
16:24.47 *** join/#brlcad Elperion (n=Elperion@p54877b4b.dip.t-dialin.net)
16:28.46 Maloeran Erik, send me a big endian cache! You told me that already :p
16:29.02 Maloeran It can't be much to fix, but I need a big endian cache
16:39.33 brlcad should just always write the cache out in network order, then the format is well known
16:41.02 brlcad that's why all the posix routines exist for this :)
16:41.39 ``Erik I'd need to get approval to send ya that... I like just writing out in network (correct) order... um
16:41.52 ``Erik rtcmp has a triangle cache file that's held that way... I think it even works
16:41.54 ``Erik O.o
16:46.42 Maloeran Network order involves unnecessary byte swapping
16:47.35 Maloeran If graphs are to be synchronized in a distributed processing network, with geometry being constantly modified, avoiding the byte swapping just makes sense
16:47.57 ``Erik um, depends on what endian your machine is
16:48.36 Maloeran I also prefer big endian for obscure reasons, but reality is different
16:54.38 ``Erik um, it "fails" as part of its regular process :/
16:54.47 ``Erik which is why there's all that setjmp/longjmp crap going on
16:56.13 Maloeran All right, cool
16:58.12 ``Erik um, have you looked at rtcmp over the weekend? I'm trying to abstract out the BRL-CAD crap in it some to simplify rayforce/rayforce.c
16:58.56 Maloeran I looked last week, I'll update
17:02.28 ``Erik all the librt stuff was removed from adrt/adrt.c and put into tri.c, which does caching out to a file
17:02.53 ``Erik which means all you have to do is cope with a simple linked list with straight xyz float data
17:25.36 ``Erik http://www.eatliver.com/i.php?n=1284
17:31.13 Maloeran If I knew any modelling software rather than writing code to do it, I suspect the task would be easier
17:36.14 brlcad uhm.. you're reading/writing to disk .. which is usually at least an order of magnitude more time-consuming than any "unnecessary byteswapping" .. which is why it flat out doesn't matter -- if you have a profile that shows otherwise, that would probably be worthy of academic publication
17:37.31 Maloeran brlcad, graph caches are also used for distributed processing synchronisation
17:39.25 brlcad i don't think you're stupid, you just make bizzare statements that smell of inexperience or pedantic religion where it really doesn't matter (sometimes)
17:39.43 brlcad think you're quite brilliant actually, novel approaches
17:39.54 *** join/#brlcad digitalfredy_ (n=digitalf@200.71.62.161)
17:40.14 brlcad but i still fail to see how the use of the files/data has any bearing on byte swapping -- educate me? :)
17:40.53 brlcad if you have to read disk, and that is the IF .. then byte swapping doesn't matter since 99% or better of your time is spent on an uncontrolled I/O variable
17:41.11 Maloeran Indeed
17:41.50 brlcad if you're not reading disk or talking about memory mapped stuff that might be optimized to avoid I/O then things can change.. but nothing you've said indicated this
17:41.53 Maloeran When updating graphs over a network for distributed processing though, any unnecessary work should be avoided
17:42.13 Maloeran The same graph caches are used for disk storage or synchronisation
17:44.35 brlcad there's certainly some disjoint in the conversation, or something you're just not saying perhaps
17:44.50 brlcad that's all fine and well understood -- that doesn't change the nature of I/O
17:45.02 brlcad disk I/O in particular
17:46.09 Maloeran Of course, I don't deny that any disk I/O will be a far bigger bottleneck than swapping bytes
17:46.11 brlcad having it be one encoding in a heterogenous environment is what makes it necessary, else you just punt on portability and only support big/little
17:46.22 ``Erik or network i/o, even with smokin' fast network
17:46.41 brlcad exactly.. that's all utterly dwarfed
17:46.41 Maloeran But during distributed processing, the nodes don't necessary "block" waiting for the data to arrive, they can be kept busy with previously queued work
17:48.25 Maloeran The impact might be small, but it wasn't much more trouble in the code either. I'm sure it will be quickly fixed as soon as I can see a big endian cache
17:48.41 brlcad er, I wouldn't have imagined that you'd make the processing nodes swap bytes - whatever *actually* reads/writes to disk would
17:49.02 brlcad which with distributed, would be a different node, so the non-blocking becomes irrelevant
17:49.40 ``Erik brlcad, are you in the office today?
17:49.47 brlcad the other point is that hton*() functions aren't just little/big endian -- there are other formats
17:49.59 brlcad ``Erik: no
17:50.02 ``Erik bah
17:50.05 Maloeran I see, I didn't really consider other formats
17:50.29 ``Erik hrm
17:50.41 ``Erik been a long time since I've heard of any of the other formats, like 'middle' endian
17:51.45 brlcad this is true, it's a minor consideration, but part of the overall purpose and portability
17:53.56 brlcad aside from the other reasons mentioned .. I mean eventually something is effectively doing a write()/read() ..
17:54.34 ``Erik heh, "bits is bits" at the end of the day, yes :)
17:55.47 brlcad i can understand a "don't want to do it", or "don't like it" even, or one of several other reasons, but just not in the namesake of performance
17:56.17 Maloeran As I said, it's just that the processors are not necessarily idle while receiving data from the network
17:57.00 Maloeran Performing byte swapping on network I/O is clearly unnecessary if nodes are of the same endianness
18:00.56 brlcad disk, man .. disk! are these caches only in memory or something (a critical detail failed to be mentioned)?
18:02.32 Maloeran When doing distributed processing synchronisation, there is no disk I/O involved!
18:02.55 ``Erik network i/o can be almost as horrible as disk i/o :)
18:03.30 ``Erik now with decent hw and drivers (dma) and "zero-copy" networking we see in SOME os's (um, linux, fbsd, and MAYBE solaris?), that's an offloaded task
18:03.32 ``Erik but it's still there
18:03.51 brlcad you could have mentioned that earlier (distributed sync has no implication of whether disk is involved) .. though similar holds for network I/O too
18:06.19 brlcad and even for in-memory is seriously prematurely-optimizing in a manner that impacts the architecture
18:07.10 ``Erik also makes assumptions about the basic paradigms
18:07.12 brlcad imho at least, it seems counterproductive to the goal and unnecessarily complicates
18:07.14 ``Erik um
18:07.35 ``Erik does every node carry a complete copy of the data set? or are nodes specialized?
18:07.49 ``Erik is this only a hit at the very beginning? or does it happen through "regular processing"?
18:07.49 brlcad but hey, i'm not writing it, so have fun :)
18:07.50 ``Erik etc
18:11.18 *** join/#brlcad Twingy (n=justin@74.92.144.217) [NETSPLIT VICTIM]
18:18.31 ``Erik http://www.wreckedexotics.com/newphotos/weird/weird796.shtml
18:18.36 ``Erik holy crap, the driver survived
18:18.55 ``Erik at least my dead exotic isn't shown there, heh, yet
18:24.32 Maloeran ``Erik, all nodes maitain a complete copy of the data set, any changes on the master node is spread on the network
18:25.07 Maloeran Graph caches are used to provide or update graphs, so it happens during "regular processing" if dynamic geometry is involved
18:25.14 ``Erik so if I have 79 gigs of triangle data... *cough* O:-)
18:25.34 Maloeran In a single model? Then you may have a problem :)
18:26.08 Maloeran It just means you won't be able to enable master/slave relationship, instead using "peers" and manage state yourself using different smaller models
18:37.53 ``Erik mal! didja grab an update of rtcmp?
20:04.40 *** join/#brlcad dli (n=dli@400exp229.anlgh.org)
20:05.12 dli can I label dimensions with brlcad? like in the traditional blueprint
20:25.16 brlcad dli: not easily -- that's more of a drafting facility than one specific to solid modeling and (as such) hasn't really been well developed
20:25.28 brlcad would be a great feature to have though, and not too complicated
20:27.37 dli brlcad, yeah, after getting my design, it's a pity that all dimensions are known but not be able to show
20:46.07 brlcad not a great solution in the least, but you could add them manually with an image editor, depending on the purpose
20:54.07 *** join/#brlcad CIA-21 (i=cia@cia.navi.cx) [NETSPLIT VICTIM]
21:00.15 Maloeran Erik, your configure script gave me : "checking for rt_prep in -lrt... no" because it doesn't find tcl. Next, I get tri.c:234: error: too few arguments to function 'bu_realloc
21:00.30 Maloeran error: 'nmg_bool_eval_silent' undeclared too
21:26.12 *** join/#brlcad Elperion (n=Elperion@p54877b4b.dip.t-dialin.net)
22:07.10 *** join/#brlcad docelic (n=docelic@212.15.173.175)
22:11.23 Maloeran The undocumented and obscure SDL 1.3 CVS sure is hard to figure how to patch N-buffering, they changed the whole video API
22:19.06 Maloeran As far as I can see, they are mostly dropping 2d capabilities, buffer flipping sure is gone
22:51.29 Maloeran Grah! Why is ./configure not putting anything in its .h file from a AC_CHECK_FUNCS(SDL_SetScreenSurface) ? It is found : checking for SDL_SetScreenSurface... yes
23:19.03 Maloeran ( Solved, deleting the cache did it )

Generated by irclog2html.pl by Jeff Waugh - find it at freshmeat.net! Modified by Tim Riker to work with blootbot logs, split per channel, etc.