Re:Ask HN: What's the worst piece of software you use everyday?
by yjftsjthsd-h on Saturday July 11, 2020 @03:43PM
(#23805235)
I know it's not bad on CPU, but I thought it took more of a hit on I/O? Granted, I suspect that some of this is indeed some issue with Darwin itself, or at least poor integration with it.
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Re:Ask HN: What's the worst piece of software you use everyday?
by jlokier on Saturday July 11, 2020 @04:17PM
(#23805529)
I agree, I/O can be pretty expensive.
It depends quite a lot on the kind of I/O and how it's implemented, so design choices matter.
If there's a full Linux kernel inside the VM, then you may as well do I/O inside the VM as well, using something like virtio and a ringbuffer of async block device commands to the host, or at least batching them. That will be quicker than relaying every POSIX file operation synchronously to the host, because the number of VM exits is much lower in the former case.