Programming Interface Information:
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used as Programming Interfaces of z/VM. |
PPDBK
Control Block Contents
PPDBK DSECT
Cross Reference (Contains links to field and bit definitions)
PPDBK Prolog
Name : HCPPPDBK Description: Paged PGMBK Data block DSECT : PPDBK Function : A PPDBK contains information required to find and process an STE corresponding to a paged PGMBK (PTRM page) which has been paged to DASD. Located by : The PPDBK address is saved in the invalid PTRM PTE for PTRM pages (paged PGMBKs) that reside on DASD. The address is saved in a hashed format so that the Invalid and Page Protect bits of the PTRM PTE are left undisturbed; HCPISTEA macro is used to insert the PPDBK address into the PTRM PTE, HCPGSTEA macro is used to extract the PPDBK address from the PTRM PTE. Created by : HCPPRPOP/HCPHRPOP when a PTRM page is invalidated, in preparation for the PTRM page (pageable PGMBK) potentially being paged to DASD. HCPMIPRB/HCPPMPRB when a PTRM page (paged PGMBK) is migrated from expanded storage to DASD. HCPPRUSM/HCPHRUSM when processing a segment table relocation, and a PTRM page (pageable PGMBK) on DASD, but without a PPDBK address in the PTRM PTE, is encountered. Deleted by : HCPPTUPF/HCPHTUPF when a PTRM page (paged PGMBK) is is read in from DASD. HCPPTAQA when a PTRM page (pageable PGMBK) is paged to expanded storage instead of DASD. Serialized : Serialized by PTRM PTE serialization, though to use or change the PPDSTE field, (at least) a share of VMDPTIL on the virtual configuration that owns the the corresponding segment table entry is required, to serialize against concurrent destructive changes to the segment table (such as segment table relocate for resize during NSS/DCSS imbed/unimbed). Comments :
PPDBK Control Block Content
PPDBK DSECT
Hex Dec Type/Val Lng Label (dup) Comments ---- ---- --------- ---- -------------- -------- 0000 0 Structure PPDBK Paged PGMBK Data block 0000 0 Address 4 PPDSTE Address of STE corresponding to paged PGMBK 0004 4 Address 4 PPDVMDBK Address of the owning vconfig's base VMDBK 00000008 PPDBKLEN *-PPDBK Size of one PPDBK in bytes 00000001 PPDBKSIZ ((*-PPDBK)+7)/8 Size of one PPDBK in dws End of PPDBK definitions
PPDBK Storage Layout
*** PPDBK - Paged PGMBK Data block * * +---------------------------+---------------------------+ * 0 | PPDSTE | PPDVMDBK | * +---------------------------+---------------------------+ * 8 * *** PPDBK - Paged PGMBK Data block
PPDBK Cross Reference
Symbol Dspl Value -------------- ---- ----- PPDBKLEN 0004 00000008 PPDBKSIZ 0004 00000001 PPDSTE 0000 PPDVMDBK 0004
Last updated on 7 Jun 2001 at 11:10:39 EDT.
Copyright IBM Corporation, 1990, 2001