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Postings from August 2010
2010/8/16 Jan Dubois <jand@activestate.com>: > On Mon, 16 Aug 2010, Reini Urban wrote: >> 2010/8/16 Jan Dubois <jand@activestate.com>: >> > Could you provide some evidence for this claim? The only way a >> > "better malloc" can prevent this slowdown is by doing some kind >> > of overallocation itself. Since the algorithm in this patch >> > is not necessarily cumulative with the overallocation by malloc() >> > it is very well possible that the change has no effect at all >> > on systems with a overallocating malloc(). >> >> This is just theory. I KNOW that plain gnumalloc and freebsd realloc >> do work fine. >> But now that we have the mess someone can test it. I don't have such systems >> so I cannot test it. > > I'm getting a bit tired of you discarding Ben's actual test based on > some "knowledge" you imply to have that you can't even verify because > you don't have access to those systems. This is a technical issue, not > a religious belief! I just studied the technical papers which discuss different system mallocs. >> > Because then it wouldn't be applied to other platforms, like FreeBSD. >> >> Uuh, nobody ever complained about freebsd realloc performance. >> It was always the fastest on the planet and still is. > > I pointed out *twice* to you that Ben did actually measure it and came up > with pretty bad numbers for the freebsd reallocator. You will need to come > up with some evidence why his benchmarks should be discarded. Sorry Jan and Ben. So I seem to have misread that thread. I'm satisfied with Wolfram's patch. > To provide similar numbers for Linux and GNU malloc I've compiled bleadperl > just before and after the patch in question, both with usemymalloc=y > and usemymalloc=n. The results are just for the "1E7 chars + 1E5 x 1E1 chars" > benchmark, as that is the slowest of the bunch. I've run the benchmark > script 100 times for each Perl build and show the min/max runtimes to show > that there is quite a bit of noise: > > Before, GNU malloc: Min=38.6 Max=45.4 Avg=41.20 > Before, Perl malloc: Min= 7.9 Max=14.2 Avg=11.14 > > After, GNU malloc: Min= 9.7 Max=12.7 Avg=11.45 > After, Perl malloc: Min= 9.4 Max=13.2 Avg=11.16 > > It shows that GNU malloc on its own takes 4 times as long as GNU malloc with > the patch. GNU malloc with this patch matches the time used by the Perl > malloc (usemymalloc=y), which doesn't seem to be affected by the patch. > You seem to have Cygwin available to you. Why don't you just test the > patch and report on any actual problems instead of spreading bad attitude? Because I have other problems with blead right now. Somehow my markstack is corrupted, so I get crashes in the simpliest dynaloader boot_ calls. Sorry for my bad attitude. I thought there were no benchmarks for this patch on the general platforms. -- Reini UrbanThread Previous | Thread Next