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A comment on Kata Containers: Virtual Machines that feel and perform like containers. Parent comment

Re:Kata Containers: Virtual Machines that feel and perform l... by spockz on Monday July 17, 2023 @04:00PM (#36763244)
Which application languages and frameworks support this kind of dynamic memory allocation? For predictability in performance and throughput reasons we benchmark our Java applications on specific cpu and memory constraints and specific heap and memory settings. How would an app in a container suddenly give back ram? A garbage collected application may be able to do that by collecting garbage. Possibly. But others?
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Re:Kata Containers: Virtual Machines that feel and perform l... by rwmj on Monday July 17, 2023 @04:28PM (#36763607)
No idea about Java, but any C program will request memory using mmap, and may give it back using munmap. This doesn't work when the program is running inside a VM, but does work for containers (which are basically just regular processes).
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Re:Kata Containers: Virtual Machines that feel and perform l... by fragmede on Monday July 17, 2023 @04:59PM (#36763990)
With VM balloning, VMs are also able to claim and release memory to the hypervisor/host OS.
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Re:Kata Containers: Virtual Machines that feel and perform l... by rwmj on Tuesday July 18, 2023 @04:00AM (#36769252)
Not driven by the guest application they don't. It's frustrating that I actually work in this area and know what I'm talking about. I worked on Katacontainers back when it was Intel's Clear Containers in the late 2010s. So many people in this thread do not have a clue.
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Re:Kata Containers: Virtual Machines that feel and perform l... by spockz on Wednesday July 19, 2023 @12:11AM (#36782040)
How does this work in practice? If the application didn’t need this memory anymore because it is done with the work/data, shouldn’t it already have freed or munmapped it? Is there a signal that can be send to a process to free up and return memory?
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