diff options
Diffstat (limited to 'NEWS')
| -rw-r--r-- | NEWS | 35 |
1 files changed, 32 insertions, 3 deletions
@@ -1,14 +1,43 @@ * What's new +- Kernel tracepoints are now supported for probing predefined kernel + events without any debuginfo. Tracepoints incur less overhead than + kprobes, and context parameters are available with full type + information. Any kernel 2.6.28 and later should have defined + tracepoints. Try the following to see what's available: + $ stap -L 'kernel.trace("*")' + +- Typecasting with @cast now supports modules search paths, which is + useful in case there are multiple places where the type definition + may be found. For example: + @cast(sdev, "scsi_device", "kernel:scsi_mod")->sdev_state + +- On-file flight recorder is supported. It allows stap to record huge + trace log on the disk and to run in background. + Passing -F option with -o option runs stap in background mode. In this + mode, staprun is detached from console, and stap itself shows staprun's + pid and exits. + Specifying the max size and the max number of log files are also available + by passing -S option. This option has one or two arguments seperated by + a comma. The first argument is the max size of a log file in MB. If the + size of a log file exceeds it, stap switches to the next log file + automatically. The second is how many files are kept on the disk. If the + number of log files exceeds it, the oldest log file is removed + automatically. The second argument can be omitted. + + For example, this will record output on log files each of them is smaller + than 1024MB and keep last 3 logs, in background. + % stap -F -o /tmp/staplog -S 1024,3 script.stp + - In guru mode (-g), the kernel probing blacklist is disabled, leaving only a subset - the kernel's own internal kprobe blacklist - to attempt to filter out areas unsafe to probe. The differences may be enough to probe more interrupt handlers. - Variables unavailable in current context may be skipped by setting a - session level flag with command line option --skip-badvars now available. - This will simply substitute the otherwise error causing variable with a - literal 0 and print a warning message when the substitution has been made. + session level flag with command line option --skip-badvars now available. + This replaces any dwarf $variable expressions that could not be resolved + with literal numeric zeros, along with a warning message. * What's new in version 0.9 |