> On Dec 9, 2015, at 17:37 , Jens Alfke <[email protected]> wrote: > > >> On Dec 9, 2015, at 5:17 PM, Rick Mann <[email protected]> wrote: >> >> - By "virtual memory," I'm sure you don't mean it's swapping to disk >> (flash). Or do you? If not, how is it virtual? > > All memory is virtual in any modern OS — the only thing that sees ‘real’ > memory addresses is the kernel’s VM subsystem. ‘Virtual’ just means there’s a > layer of indirection between address space and RAM. > > On iOS it’s just that the address space normally allocated to apps (by > malloc, etc.) isn’t backed by a swap file. So it doesn’t get paged out, but > it’s also limited by the amount of physical RAM.
Ah, yes, of course. Just the address translation is happening. Yeah, I need to know if the dirty limit has increased. Alternatively, if mmap-ed memory would actually live in RAM, but get around the dirty limit (assuming for the sake of argument that the user isn't running other apps), then we really could get more memory without a speed penalty via mmap(). > > By “how much virtual memory you can use” I believe Rick means how much > _address space_. No, I need to know how much I can actually allocate and dirty. -- Rick Mann [email protected] _______________________________________________ Cocoa-dev mailing list ([email protected]) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: https://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to [email protected]
