alt Hacker Newshttps://learn.microsoft.com/en-us/sysinternals/downloads/vmm... for an empty sublime text window gives me:
- 100MB 'image' (ie executable code; the executable itself plus all the OS libraries loaded.)
- 40MB heap
- 50MB "mapped file", mostly fonts opened with mmap() or the windows equivalent
- 45MB stack (each thread gets 2MB)
- 40MB "shareable" (no idea)
- 5MB "unusable" (appears to be address space that's not usable because of fragmentation, not actual RAM)
Generally if something's using a lot of RAM, the answer will be bitmaps of various sorts: draw buffers, decompressed textures, fonts, other graphical assets, and so on. In this case it's just allocated but not yet used heap+stacks, plus 100MB for the code.
Edit: I may be underestimating the role of binary code size. Visual Studio "devenv.exe" is sitting at 2GB of 'image'. Zoom is 500MB. VSCode is 300MB. Much of which are app-specific, not just Windows DLLs.
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But I have sublime text open with a hundred files and it's using 12mb.
Turning these numbers into "memory consumption" gets complicated to the point of being intractable.
The portions that are allocated but not yet used might just be page table entries with no backing memory, making them free. Except for the memory tracking the page table entries. Almost free....
A lot of "image" will be mmapped and clean. Anything you don't actually use from that will be similarly freeish. Anything that's constantly needed will use memory. Except if it's mapped into multiple processes, then it's needed but responsibility is spread out. How do you count an app's memory usage when there's a big chunk of code that needs to sit in RAM as long as any of a dozen processes are running? How do you count code that might be used sometime in the next few minutes or might not be depending on what the user does?
Tx for the breakdown. I will play around with it later on my windows machine.
But isn't it crazy how we throw out so much memory just because of random buffers? It feels wrong to me