On 19 December 2017 at 00:35, Andreas Brodbeck <da...@mindclue.ch> wrote:
> Hi all! > > I have a performance problem with Fuel (latest stable) on a Pharo 6.1 > (32bit) on Ubuntu 16.04.3 LTS. The serialization and storage to disk of > 70MB of data takes more than 6 minutes! While the same task on an > equally powerful Mac takes only 1.5 minutes. > > My observation was, that on Linux it is very very slow while writing the > file. The first 30MB of the file are written very fast, but after that > the writing speed drops dramatically. > > On the same Linux server, but the application running on an old Pharo > 1.4, the serialization was always as fast as on the Mac. > > Attached you see an excerpt of the Pharo Time profiler output for the > serialization. The profiling tree looks the same on the Mac, just with > faster times. > > What could be the hidden speed eating secret on Linux for Pharo6.1? I > have absolutely no idea where to search! Memory? Streams? File writing > support? Something inside Fuel? > On 19 December 2017 at 03:45, Henrik-Nergaard <draag...@outlook.com> wrote: > 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). > > 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 better performance? > side comment: I wonder what could be the performance of hooking #serializeToByteArray: up directly to mmap ? * http://forum.world.st/Pharo-Shared-Memory-with-C-executable-td4921928.html * http://forum.world.st/ANN-CPPBridge-One-Ring-to-rule-them-ALL-td4922275.html#a4922302 cheers -ben
