The LDR_CNTRL environment variable controls the way AIX® handles the memory space available to a 32-bit program and the page sizes used in each segment. The POWER4™ and later PowerPC® processors support the use of 16 MB large pages in addition to the default 4 KB pages. The POWER5+™ and later PowerPC processors add support for two new page sizes, 64 KB and 16 GB.
Controlling the available memory space
The SDK typically sets appropriate LDR_CNTRL=MAXDATA settings automatically for the size of the Java™ heap. However, if you explicitly set the LDR_CNTRL=MAXDATA environment variable the SDK will not override the value you have specified. Do not override the automatic settings unless you have a complete understanding of the AIX memory models. For more information about the AIX memory models and the automatic settings used by the SDK, see SDK use of AIX large program support.
Page sizes
AIX v5.2 and later operating systems support 16 MB pages. AIX v5.3 maintenance package 5300-04 on POWER5+ processors adds support for the 64 KB and 16 GB page sizes. The 16 MB and 16 GB pages require AIX system configuration changes. For information on using 16 MB pages with AIX, see http://www.ibm.com/servers/aix/whitepapers/large_page.html. For information about using either 64 KB or 16 GB pages with AIX, see http://www.ibm.com/servers/aix/whitepapers/multiple_page.pdf. The default AIX page size is 4 KB.
The LDR_CNTRL=LARGE_PAGE_DATA environment variable can be used under the AIX v5.2 and later operating systems to control the use of 16 MB pages for the native data area and native heap of a program. You can use 16 MB large pages, if they are available, by setting LDR_CNTRL=LARGE_PAGE_DATA=Y. Using large pages might improve the performance of Java applications that require a large amount of native heap space. In particular, the native heap is used for machine code generated by the just-in-time compiler and Java applications with a large number of compiled methods might benefit from using 16 MB pages for the native heap.
AIX v5.3 maintenance package 5300-04 added LDR_CNTRL variants that independently control the use of different page sizes for the text (TEXTPSIZE), stack (STACKPSIZE) and native data or heap (DATAPSIZE) areas. See the Guide to Multiple Page Size Support on AIX 5L Version 5.3 for general information about these variants: http://www.ibm.com/servers/aix/whitepapers/multiple_page.pdf.
An example of the use of TEXTPSIZE, STACKPSIZE, and DATAPSIZE variants is:
LDR_CNTRL=TEXTPSIZE=4K@STACKPSIZE=64K@DATAPSIZE=64K
This example uses 4 KB pages for text, 64 KB pages for stack and 64 KB pages for the native data and native heap areas. A DATAPSIZE setting will override any LARGE_PAGE_DATA setting.
In the default AIX 5L™ 32-bit process address space model, the initial thread stack size and data of a process are located in the same PowerPC 256 MB segment. Only one page size can be used in a segment. If different page sizes are specified for the stack and data of a standard 32-bit process, the smaller page size will be used for both. See the Guide to Multiple Page Size Support on AIX 5L Version 5.3 for information about how to use different segments for the stack and data of a process: http://www.ibm.com/servers/aix/whitepapers/multiple_page.pdf.
When page sizes are set using LDR_CNTRL, the SDK does not automatically set MAXDATA and it is set to MAXDATA=0. To use a Java heap larger than 2.5 GB, set MAXDATA to a different value. See SDK use of AIX large program support for more information about possible settings. For example:
LDR_CNTR=MAXDATA=0XB0000000@DSA@TEXTPSIZE=4K@STACKPSIZE=64K@DATAPSIZE=64K
The new 64 KB pages are general-purpose and most workloads will see a benefit by using 64 KB pages for text, stack, native data, and the Java heap. The 16 GB pages are intended only for use in very high performance environments.
Note: Use the -Xlp option variants to request that the JVM allocates the Java heap with a specific size of pages.
For more information about using the LDR_CNTRL environment variables and on configuring AIX support for large pages, see http://www.ibm.com/servers/aix/whitepapers/large_page.html for AIX v5.2 information on 16 MB pages, and http://www.ibm.com/servers/aix/whitepapers/multiple_page.pdf for information on AIX v5.3 support of 64 KB and 16 GB pages.
Parent topic: Running Java applications
分享到:
相关推荐
ARM LDR指令和LDR伪指令的总结,搞ARM的朋友建议看看!
资源来自pypi官网。 资源全名:ir_ldr_mingjie-0.1.4-py3-none-any.whl
LDRs or Light Dependent Resistors are very useful especially in light/dark sensor circuits.
ldr arduino 1 test okkkkkkkkkkkkkk
ldr programe test 2 okkkkkkkkk
ldr systen for home and car
易语言隐藏动态库源码,隐藏动态库,子程序1,LDR_DATA_TABLE_ENTRY,隐藏模块,取模块句柄_,DLL命令1
Temp_IR_LDR_TASK:ATMEGA 32
图像处理领域中用于处理LDR为HDR图像的程序,即从低动态范围的图像转成高动态范围的图像
programa en C muy sencillo en el que mediante un sensor de luz encendemos una serie de diodos LED en función de la intensidad de luz que capta el sensor
仿真和传统概念os有诸多不同,代码访问os所需要资源数据,都要...初始化PEB/TEB/PEB_LDR__DATA/Register。 加载导入SystemDLL - 修复IAT重定位(虚拟地址) 样本自身的Iat/重定位。 设置函数回调,处理Api执行。 异常处理
Geng's Data Unloader for Oracle 8i/9i/10g, release 1.0.2. ... All Rights Reserved. If you have any advises and suggestions, ... init.gdul db_block_size=8192 ...ldr_enclose_char=| file_leader_size=0
This is a LDR project.
##TinyTX_LDR_Meter 使用 LDR 读取电表上的 LED 脉冲。 ##TinyTX_LDR 使用 LDR 读取光照水平。 ##TinyTX_ReedSwitch 检测常闭簧片开关打开和关闭,引脚更改中断以从睡眠中唤醒。 ##TinyTX_Hall_Effect_Gas 使用 A...
LDR数据在python脚本process_LDR.py中处理,并生成json static / networks / LDR_as_cl.json。 可视化可以设置为固定大小-通过将id为svg_div的div大小(在custom.css中设置)指定-通过在arguments_obj(在index....
基于MATLAB的数字图像拼接,可以将两幅或多幅图像进行拼接
20210705_na51089_ldr.tar.bz2
HA-Proxifier30-LDR.zip HA-Proxifier30-LDR.zip
3) SRS with writeback must have a separating space after the mode number and before "!" (eg. "SRSDB 16 !" instead of "SRSDB 16!") 4) macro, rept, irp, format, if, virtual etc. are all significant ...