> > > What Ben pointed out was virtual memory reservations, which is not the > same as restricted space sizes. > > Would you guys mind expanding on this? My thinking is that the v8 commits > as much memory as it is allowed for semi/old/code spaces (considering that > the app doesn't allocate more than fits into these spaces), plus for the > C++ machinery to maintain these objects and if those sizes are limited to > some reasonable size, why would v8 reserve more memory that it cannot > commit? >
Memory address space is separate from actual memory. There are cases where it makes sense to reserve a large chunk of address space without requesting it to be backed by actual memory, usually when a contiguous range may be required later. For example, on 64-bit platforms, V8 requires all executable memory to be within a 2GB section of address space so that calls can use 32-bit offsets, so it reserves that amount of address space on initialization (which is a very cheap operation), whereas actual memory is allocated later as needed. WebAssembly has a similar use case where a large section of address space is reserved so that *if* it needs to use that memory later, the addresses will be contiguous. -- -- v8-users mailing list v8-users@googlegroups.com http://groups.google.com/group/v8-users --- You received this message because you are subscribed to the Google Groups "v8-users" group. To unsubscribe from this group and stop receiving emails from it, send an email to v8-users+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
