That’s one of the many reasons I think Windows NT kernel is generally better than Linux.
Windows doesn’t do that. When you don’t have enough memory and not enough page file space either, these allocation functions usually do fail returning nullptr.
Windows doesn’t do that. When you don’t have enough memory and not enough page file space either, these allocation functions usually do fail returning nullptr.
Wow, this seems really unintuitive to me, especially on a OS that doesn't overcommit. Is it as unintuitive as it sounds, or is there a good reason for this?
I’m guessing the description in the WDDM docs about DDI might be relevant to what’s happening under the covers in WDDM2? I’m not sure… :) https://docs.microsoft.com/en-us/windows-hardware/drivers/di...
Multitasking.
User can easily alt+tab into another program which also uses GPU. When many processes are using GPU concurrently, it's possible their combined VRAM use exceeds the amount of physical memory available on the GPU.
Assuming that the work needs to be done? You can either do that on allocation (which you can predict, batch, etc) or you can do that when you need the next page to be used. Which is far harder to predict and work with.
https://www.kernel.org/doc/Documentation/vm/overcommit-accou...
Also, I found this post that suggests Windows technically does overcommit memory, but only for stacks(‽): https://superuser.com/questions/1194263/will-microsoft-windo...
I’m sure there are other horrendously degraded modes that Linux can theoretically operate in (read-only file system?, unreliable system clock?), but disabling overcommit, while possible, turns Linux into an exceedingly crummy OS.