Dear everybody, 
    I'm using one of your component (LMDB) via a java JNDI bindings
implementation (https://github.com/deephacks/lmdbjni) and I'm having an issue
when I deploy my LMDB file on a tempfs filesystem in RAM. 

The issue do not occur when the LMDB files are stored on a "normal" filesystem.
When the data is in the tempfs ramdisk all the allocated memory ends up being in
the Dirty area (it has not been written back to the Filesytem). 

Here an example using the ramdisk: 

7ce320000000-7cfc20000000 r--s 00000000 00:26 2459                      
/ramfs/nerd/data/db/db-en/entityEmbeddings/data.mdb
Size:           104857600 kB
Rss:             1255680 kB
Pss:             1255680 kB
Shared_Clean:          0 kB
Shared_Dirty:          0 kB
Private_Clean:         0 kB
Private_Dirty:   1255680 kB    <---
Referenced:      1255680 kB
Anonymous:             0 kB
AnonHugePages:         0 kB
Shared_Hugetlb:        0 kB
Private_Hugetlb:       0 kB
Swap:                  0 kB
SwapPss:               0 kB
KernelPageSize:        4 kB
MMUPageSize:           4 kB
Locked:                0 kB
VmFlags: rd sh mr mw me ms sd 

and here an example without: 

7ca4fc000000-7cbdfc000000 r--s 00000000 fd:00 11154951                  
/data/workspace/shared/nerd-data/db/db-en/entityEmbeddings/data.mdb
Size:           104857600 kB
Rss:              838124 kB
Pss:              838124 kB
Shared_Clean:          0 kB
Shared_Dirty:          0 kB
Private_Clean:    838124 kB       <----
Private_Dirty:         0 kB
Referenced:       764872 kB
Anonymous:             0 kB
AnonHugePages:         0 kB
ShmemPmdMapped:        0 kB
Shared_Hugetlb:        0 kB
Private_Hugetlb:       0 kB
Swap:                  0 kB
SwapPss:               0 kB
KernelPageSize:        4 kB
MMUPageSize:           4 kB
Locked:                0 kB
VmFlags: rd sh mr mw me ms sd 


According to my understanding the memory is dirty when 1)there are open
transactions, 2) the data has not been written back to the filesystem 

What I don't understand is why there is a difference between filesystem and
ramdisk? 
Is there any reason? The application (listed above) is not writing on the lmdb,
but just reading (using reading transaction). 

Thank you
Luca