201 lines
3.5 KiB
HTML
201 lines
3.5 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
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<HTML
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><HEAD
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><TITLE
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>Changes between lk 2.2 and (during) 2.4</TITLE
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><META
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NAME="GENERATOR"
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CONTENT="Modular DocBook HTML Stylesheet Version 1.7"><LINK
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REL="HOME"
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TITLE="The Linux 2.4 SCSI subsystem HOWTO"
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HREF="index.html"><LINK
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REL="PREVIOUS"
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TITLE="Common bus types (SCSI and other)"
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HREF="scsibus.html"><LINK
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REL="NEXT"
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TITLE="Mid level changes"
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HREF="chgml.html"></HEAD
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><BODY
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CLASS="appendix"
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BGCOLOR="#FFFFFF"
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TEXT="#000000"
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LINK="#0000FF"
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VLINK="#840084"
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ALINK="#0000FF"
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><DIV
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CLASS="NAVHEADER"
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><TABLE
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SUMMARY="Header navigation table"
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TH
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COLSPAN="3"
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ALIGN="center"
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>The Linux 2.4 SCSI subsystem HOWTO</TH
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></TR
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><TR
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><TD
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WIDTH="10%"
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ALIGN="left"
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VALIGN="bottom"
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><A
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HREF="scsibus.html"
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ACCESSKEY="P"
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>Prev</A
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></TD
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><TD
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WIDTH="80%"
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ALIGN="center"
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VALIGN="bottom"
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></TD
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><TD
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WIDTH="10%"
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ALIGN="right"
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VALIGN="bottom"
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><A
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HREF="chgml.html"
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ACCESSKEY="N"
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>Next</A
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></TD
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></TR
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></TABLE
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><HR
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ALIGN="LEFT"
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WIDTH="100%"></DIV
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><DIV
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CLASS="appendix"
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><H1
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><A
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NAME="changes"
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></A
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>Appendix B. Changes between lk 2.2 and (during) 2.4</H1
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><DIV
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CLASS="TOC"
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><DL
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><DT
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><B
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>Table of Contents</B
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></DT
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><DT
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>B.1. <A
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HREF="chgml.html"
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>Mid level changes</A
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></DT
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><DT
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>B.2. <A
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HREF="chgsd.html"
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>sd changes</A
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></DT
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><DT
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>B.3. <A
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HREF="chgsr.html"
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>sr changes</A
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></DT
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><DT
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>B.4. <A
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HREF="chgst.html"
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>st changes</A
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></DT
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><DT
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>B.5. <A
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HREF="chgsg.html"
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>sg changes</A
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></DT
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><DT
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>B.6. <A
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HREF="chg24.html"
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>Changes during the lk 2.4 series</A
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></DT
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></DL
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></DIV
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><P
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> Significant work has been done to change the single SCSI command queue
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used in lk 2.2 to one command queue per device. To make the SCSI subsystem
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more SMP friendly the granularity of the locks is much finer grained. In
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lk 2.2 the whole subsystem essentially used one lock.
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</P
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><P
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> Even though it is not part of the SCSI subsystem, the inclusion of devfs
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solves many SCSI device addressing problems that existed in the past.
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Associated with devfs but very useful even in its absence is the
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"scsihosts" kernel boot time (and module load time) option. This option
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allows users to have some control over the ordering of multiple SCSI hosts.
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</P
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><P
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> This appendix is difficult to maintain since features and drivers that
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have proven useful in lk 2.4 (and its development tree) have tended to
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be back ported into the higher release numbers of the lk 2.2 series.
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</P
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><P
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> Currently (lk 2.4.2) support for MO devices is broken. Old DOS file
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systems with a block size of 2048 bytes also have been reported as broken.
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The problem seems to arise with media that have a physical block size
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larger than the 1 KB logical block size used by the block subsystem.
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Only the sd driver has this problem (luckily not the sr driver in
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which 2048 byte sectors are the norm).
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</P
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></DIV
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><DIV
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CLASS="NAVFOOTER"
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><HR
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ALIGN="LEFT"
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WIDTH="100%"><TABLE
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SUMMARY="Footer navigation table"
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WIDTH="100%"
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BORDER="0"
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CELLPADDING="0"
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CELLSPACING="0"
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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><A
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HREF="scsibus.html"
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ACCESSKEY="P"
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>Prev</A
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></TD
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><TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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><A
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HREF="index.html"
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ACCESSKEY="H"
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>Home</A
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></TD
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><TD
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WIDTH="33%"
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ALIGN="right"
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VALIGN="top"
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><A
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HREF="chgml.html"
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ACCESSKEY="N"
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>Next</A
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></TD
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></TR
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><TR
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><TD
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WIDTH="33%"
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ALIGN="left"
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VALIGN="top"
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>Common bus types (SCSI and other)</TD
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><TD
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WIDTH="34%"
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ALIGN="center"
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VALIGN="top"
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> </TD
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><TD
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WIDTH="33%"
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ALIGN="right"
|
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VALIGN="top"
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>Mid level changes</TD
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></TR
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></TABLE
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></DIV
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></BODY
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></HTML
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> |