Emscripten allocates an ArrayBuffer for memory. In principle, browsers call internally allocate it using calloc(), which would let most OSes only create physical pages when actually needed. However, in practice, some browsers have optimizations for the location of asm.js typed arrays, which can remove some bounds checks, but it does limit the effectiveness of calloc().
In general, it is best to assume that TOTAL_MEMORY will use physical memory immediately. Memory growth is an option to use memory more flexibly, but as you said, it has perf limittaions. On Wed, Jul 27, 2016 at 8:11 AM, 'Peter Nemeth' via emscripten-discuss < [email protected]> wrote: > I was digging this a bit more and it's not the browser but the OS. What > Activity Monitor / Task Manager shows is the resident memory. The > about:memory page of Firefox clearly shows everything related (resident, > vsize, js engine, asm.js, ...). > > The questions still apply though. Can I rely on this in practice (given > the browser is 64 bit, 32 bit browsers are worse from this point)? Tips for > production? > > > 2016. július 26., kedd 15:10:27 UTC+2 időpontban Peter Nemeth a következőt > írta: >> >> I'm trying to find out the best memory configuration for our application. >> It's using a lot of user generated content so we cannot be sure about the >> required TOTAL_MEMORY at compile time. We could calculate that upfront on >> the backend and set in the Module before loading but I would like to avoid >> that if possible. Also don't want to enable memory growth because of its >> performance drawbacks. After checking some browsers with a simple test it >> seems like they are smart enough not to allocate the whole buffer in C++ >> regardless the requested size of the ArrayBuffer. Do you know if this works >> in practice? How is Emscripten handling the HEAP stack-, and heap-wise? >> Where are they located in the HEAP? Any tips from production applications >> how they solve memory configuration? >> > -- > You received this message because you are subscribed to the Google Groups > "emscripten-discuss" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "emscripten-discuss" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
