- 论坛徽章:
- 0
|
回复 1楼 ahcnpl 的帖子
There is a sunsolve article regarding this. I post it here for your reference.
Document Audience: SPECTRUM
Document ID: 85550
Title: Why do libc_psr_hwcap1.so.1 and libc_psr.so.1 show as mount points?
Copyright Notice: Copyright © 2006 Sun Microsystems, Inc. All Rights Reserved
Update Date: Fri May 26 00:00:00 MDT 2006
Products: Solaris 10 Operating System
Technical Areas: Commands
--------------------------------------------------------------------------------
--------------------------------------------------------------------------------
Keyword(s):df, mount, libc_psr_hwcap1.so.1, libc_psr.so.1
Description Top
The purpose of this document is to help explain why the mount points detailed below are shown from df(1M) and mount(1M)
Document Body Top
Under some circumstances, such as an operating system upgrade or patch installation, the following mount points may be shown from df(1M) and mount(1M):
/platform/sun4u-us3/lib/libc_psr/libc_psr_hwcap1.so.1 mounted on /platform/sun4u-us3/lib/libc_psr.so.1
---
/platform/sun4u-us3/lib/sparcv9/libc_psr/libc_psr_hwcap1.so.1 mounted on /platform/sun4u-us3/lib/sparcv9/libc_psr.so.1
--
An example of what could create these mounts is an OS upgrade to Solaris 10 (Update X) or the installation of patch 122750-XX.
Note: these are just examples - it may not be restricted to this
These mounts will not show on all systems as the change is hardware specific, which the patch and OS are not.
---
Why is this?
The mount points detailed have been created intentionally by engineering. In basic terms, they are a platform specific enhancement to ensure full application performance is achieved. This is done by changing the way the Operating System fully utilizes the potential of the CPU for the platform.
The libc_psr libraries implement platform-specific, optimized versions of block copy and move routines from libc, such as memcpy(). On UltraSPARC machines, these routines are coded in assembler, and use block load and store ASI's, prefetch, and other tricks for better performance.
This is enabled using the HWCAP feature of the linker; see the linker guide for details (http://docs.sun.com/app/docs/doc/817-1984).
The alternate routines live in the libc_psr_hwcap1.so.1 library. At boot time, the libc_psr_hwcap1.so.1 library is loop-back mounted onto the libc_psr path using a combination of the moe(1) utility, and mount -F lofs, invoked from the start method of the svc:/system/filesystem/root service (/lib/svc/method/fs-root). As this is a loopback mount, no disk space is waisted.
This is the only way that this enhancement can be implemented, and at this time will not be changed. Disabling this functionality is not possible or supported. |
|