On Tue, Dec 19, 2017 at 7:40 AM, Andreas Brodbeck <da...@mindclue.ch> wrote:
> Am 18.12.17 um 20:45 schrieb Henrik-Nergaard: > > Hi Andreas, > > > > It looks like you may have problems with hash collisions > > FLLargeIdentityDictionary. > > What are the tally sizes of the FLLargeIdentityDicitonary used when you > > serialize? (If these have a tally larger than ~ 75% of the available size > > (4096 items), then there may well be some performance loss). > > Well, hm, I have FLLargeIdentityDicitonary instances with up to 300'000 > items... But that's what "large" means, right? > > Is there anything I can do here? I don't think so. > > > > > You could check if file writing is the problem by measuring the time it > > takes to only serialize in memory. > > You can try to use: "FLSerializer serializeToByteArray: " and see if it > > gives petter performance? > > Thanks for this hint! I did that, and measured the same crazy > difference, 6minutes vs. 1.5 minutes. > > So: It's not the storage! It's something inside Fuel. I keep > investigating and will update here. > > Hi Andreas, Reading the thread nothing obvious comes to my mind. Sorry. My guy feeling is that some of the primitives used by FLLargeIdentityDicitonary become slower in latest VMs. I guess the main one to check is #fuelPointsTo: (primitive 132) (see the senders). Maybe you can do a quick test (isolated from your app) and compare agains old pharo ? Another thing would be comparing your scenario using a identity set. Just save your image before doing this: | set dict | set := FLLargeIdentitySet. dict := FLLargeIdentityDictionary. Smalltalk at: #FLLargeIdentitySet put: IdentitySet. Smalltalk at: #FLLargeIdentityDictionary put: IdentityDictionary. And re-run the serialization. Anyway, cannot think of much more things now. Cheers,
