What does the vmem_pool mapping file store? And can we access that information?

[Tonmoy Dey]

What does the vmem_pool  mapping  file store? And can we access that information? 

I need to perform compaction so I want to know if I can get mapping information between application level variable and the vmem address.

[Piotr Balcer]

You can see the layout of `struct vmem` in the vmem.h file in libvmem's implementation.

It's mostly metadata for the allocator.

I'm not sure if I understand your use-case, but we strongly advise against relying on any

internal implementation details, such as the vmem struct definition.

[Chris Yu]

I think it's a temp file which you would not see normally but actually exists. 

在 2019年5月21日星期二 UTC+8上午3:40:06，Tonmoy Dey写道：

[Tonmoy Dey]

I need to find a way to create a mapping between the virtual address returned after allocation and the actual persistent memory address. It can be anywhere and it need not be in the libvmem library.

I plan to access the byte addressable memory of the persistent memory and map it to the virtual address returned so that in the future I can rearrange allocations just by changing the actual location where the virtual address points to. Simply put I need to perform compaction of memory later, for which if I can find a mapping mechanism it would be possible to rearrange objects.

Kindly let me know if you are aware of such functionality in PMDK.