On 10/04/17 12:06, Segher Boessenkool wrote: > On Mon, Apr 10, 2017 at 12:52:15PM +0200, Markus Trippelsdorf wrote: >>> --param ggc-min-heapsize=131072 >>> 11264.89user 311.88system 24:18.69elapsed 793%CPU (0avgtext+0avgdata >>> 1265352maxresident)k >> >> --param ggc-min-heapsize=262144 >> 10778.52user 336.34system 23:15.71elapsed 796%CPU (0avgtext+0avgdata >> 1277468maxresident)k >> >>> --param ggc-min-heapsize=393216 >>> 10655.42user 347.92system 23:01.17elapsed 796%CPU (0avgtext+0avgdata >>> 1280476maxresident)k >>> >>> --param ggc-min-heapsize=524288 >>> 10565.33user 352.90system 22:51.33elapsed 796%CPU (0avgtext+0avgdata >>> 1506348maxresident)k > > So 256MB gets 70% of the speed gain of 512MB, but for only 5% of the cost > in RSS. 384MB is an even better tradeoff for this testcase (but smaller > is safer). > > Can the GC not tune itself better? Or, not cost so much in the first > place ;-) > > > Segher >
I think the idea of a fixed number is that it avoids the problem of bug reproducibility in the case of memory corruption. R.
