The Virtual Page Structure

VPs track the disposition of every page of virtual storage of every object. They enable the system to locate the data for the page, whether it is in RAM or on the Swap file.

VPs are formatted using the .MV KDB and DF command, which takes as a parameter the address of the VP, which may be obtained from the PF structure.

.mv %ff4060f0 l5
VPI=0018 pVP=ff4060f0 Res Frame=0011 Flg=410 HobPg=0001 Hob=0009 Ref=001
VPI=0019 pVP=ff4060fa Res Frame=0012 Flg=410 HobPg=0002 Hob=0009 Ref=001
VPI=001a pVP=ff406104 Res Frame=0013 Flg=410 HobPg=0003 Hob=0009 Ref=002
VPI=001b pVP=ff40610e Swp Block=08cc Flg=0a0 HobPg=027b Hob=0026 Ref=001
VPI=001c pVP=ff406118 Swp Block=0001 Flg=000 HobPg=0000 Hob=00e7 Ref=001

Of particular interest are:

Hob=nnnn

The hob of the object to which this page belongs.
HobPg=nnnn
The page number within the object.
Frame=ffff
The real storage frame number that backs this virtual page.
Block=bbbb
The Swap file 4K block that contains the data for this virtual page.

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