~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~ RedHat Advanced Server (RHAS) 2.1
~
~ Default Configuration w/o Enterprise Kernel with <4Gb of RAM
~
~ >>>SGA MAX Size 1.7 GB<<<
~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Configuration : 3+1 3Gb user process +1Gb Kernel
On normal kernel we have the following default memory layout for every process:1.0 GB Text/code
1.7 GB available process memory for mmap, malloc /
address space (e.g. usable by shared Pool)
0.3 GB Stack
1.0 GB Kernel==> 4 – 1 – 1 – 0.3 = 1.7GB left for SGA
A picture of Memory Layout:
---------------------------4GB +------------------+ 0xFFFFFFFF
| |
| Kernel stuff |
| | 0xE0000000 SSKGMTOP
| | (from sskgm.h may17 label)
| |
3GB +------------------+ 0xC0000000 __PAGE_OFFSET
| | Stack grows | (include/asm-i386/page.h)
| v down... |
2.98GB |------------------| 0xBF000000
| |
| |
| Oracle SGA |
| max 1776MB |
| max 1.75GB |
| |
| |
| |
| |
| |
| |
| |
| |
1.25GB +------------------| 0x50000000 GENKSMS_SGA_ADDR
| Shared libraries |
| lib*.so |
| |
| |
| |
| |
1GB +------------------+ 0x40000000 TASK_UNMAPPED_BASE
| applicaton code |
| (Oracle .text) | ^
| | |
| | 0x20000000 SSKGMBOTTOM |
| | (from sskgm.h may17 label) |
| | |
| | |
128MB |------------------| 0x08000000 |
| | |
| | |
0 +------------------+ 0x00000000 |
check
Note 260152.1
https://metalink.oracle.com/metalink/plsql/f?p=130:14:5739562173496231439::::p14_database_id,p14_docid,p14_show_header,p14_show_help,p14_black_frame,p14_font:NOT,260152.1,1,1,1,helvetica
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