Project News: DTrace
2016.10.17: DTrace userspace 0.5.2, kernel modules 0.5.2, libdtrace-ctf 0.5.0
All RPMs are available on the Unbreakable Linux Network.
Performance improvements in dtrace-utils 0.5.2:
- dtrace(1) no longer wastes time in a CPU-heavy busywaiting loop: previously,
the sleeping code was mistakenly picking a time in the past to sleep to
roughly half the time
Bugfixes in dtrace-utils 0.5.2:
- Programs containing USDT probes can crash at startup or dlopen() time if
shared libraries are mapped into the top half of the address space. This
never happens on x86-64 but is common on SPARC64: dtrace -G should be
rerun on programs on such platforms that contain USDT probes, to link in
the fixed ELF constructor.
- dtrace -c and -p now work on SPARC64.
Bugfixes in dtrace-modules 0.5.3:
- When both entry and return probes were enabled for a system call, upon
disabling the first, the function pointer in the system call table got
reset to its default value even though the 2nd probe might still be
active. This could cause race conditions in the state of the system
- Access to the SPARC64 R_L7 register was consistently failing due to an
- It was possible to read past the beginning of the stack for a user
process. The mechanism for reading stack slots also got updated to
increase efficiency, consistency and reliability across architectures.
- While reading the stack of a userspace process, the stack bias was not
being applied for architectures that need it, causing an abundance of
essentially invalid values to polute the result.