Filesystem/Storage Management; Tools; Gnu Project Debugger (Gdb) - Red Hat ENTERPRISE LINUX 5.5 - RELEASE NOTES 2010 Release Note

5. Filesystem/Storage Management

Improved CFQ I/O scheduler performance
Some applications (e.g. dump and nfsd) try to improve disk I/O performance by distributing I/O
requests to multiple processes or threads. However, when using the Completely Fair Queuing (CFQ) I/
O scheduler, this application design negatively affected I/O performance. In Red Hat Enterprise Linux
5.5, the kernel can now detect and merge cooperating queues. Additionally, the kernel can also detect
if the queues stop cooperating, and split them apart again.
New GFS2 mount option
This update introduces GFS2 support for the errors= mount command line option, which may
assist in troubleshooting. The default option, errors=withdraw results in the filesystem attempting
to withdraw from the cluster if an I/O error or metadata error is encountered. The alternative,
errors=panic results in a panic in the same situation.
CIFS Update
The Common Internet File System (CIFS) has been updated in the kernel.

6. Tools

6.1. GNU Project debugger (GDB)

The GNU Project debugger (normally referred to as GDB) debugs programs written in C, C++, and
other languages by executing them in a controlled fashion, and then printing out their data.
In Red Hat Enterprise Linux 5.5, GDB has been updated to version 7.0.1. For a detailed listing of
changes refer to the GDB section of the Technical Notes.
Enhanced C++ support
Support for the C++ programming language in GDB has been improved. Notable improvements
include:
• Many improvements to expression parsing.
• Better handling of type names.
• The need for extraneous quoting has nearly been eliminated
• "next" and other stepping commands work properly even when the inferior throws an exception.
• GDB has a new "catch syscall" command. This can be used to stop the inferior whenever it makes a
system call.
Wide and multi-byte character support
GDB now has support for wide and multi-byte characters on the target.
53
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=518106
54
https://bugzilla.redhat.com/bugzilla/show_bug.cgi?id=500838
Filesystem/Storage Management
53
(BZ#518106 )
(BZ#500838
54
)
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