DTrace TODO

This page is for brainstorming and coordinating efforts with DTrace development. Anyone who has and idea/wish can add an item and if you work on one of those you grab it. You can always mail the freebsd-dtrace mailing list in case you do not have write access to the wiki, have questions or want to work on this but are not (yet;-) a FreeBSD committer.

Most of these problems are specific to FreeBSD's DTrace implementation, but some of them are upstream (illumos) issues as well.

DTrace TODO items

added by

responsible

state

task

JohnBirrell

committed

We need a BSD version of libelf. Or at least one that can handle host endian != target endian. This affects cross-builds on dissimilar architectures (like i386 host, sparc64 target). See LibElf

JohnBirrell

StaceySon

committed

Get ustack()/jstack() actions working. See ustack patch. (Only outputs hex PC values for now because of the lack of symbol table support in libproc.)

JohnBirrell

MarkJohnston (partially)

committed

Implement args beyond arg4. See r256822 and r251238.

JohnBirrell

StaceySon

committed

Implement lockstat -- including both driver and command. See lockstat kernel patch, lockstat cmd patch, and ksyms pseudo driver.

JohnBirrell

Implement toxic ranges.

JohnBirrell

Implement stop() action.

JohnBirrell

Port MDB DTrace-related dcmds to FreeBSD debugger.

JohnBirrell

StaceySon

committed

Get stack() action working. (Committed a while ago.)

JohnBirrell

committed

Need to add mailbox IPI's to allow a function to be executed on another CPU.

JohnBirrell

Credentials and privileges need a lot of work.

JohnBirrell

The ability to trace a process running on a different CPU is an important part of DTrace. Somebody needs to test that.

JohnBirrell

MikeMa, MarkJohnston

committed

Solaris has a vmem subsystem which is an integral part of their virtual memory. FreeBSD 10 has a new vmem(9) implementation with the required functions vmem_create(), vmem_destroy(), vmem_alloc(), and vmem_free().

JohnBirrell

There are lots of places in the build where the ctfconvert and ctfmerge tools complain about the objects they are processing. Those issues need to be resolved.

StaceySon

RuiPaulo

committed

Add symbol support to libproc.

StaceySon

Add missing built-in variables: ipl, zonename (jailname)

StaceySon

StaceySon

committed

Add missing built-in variable 'uregs[]'. See uregs patch.

StaceySon

StaceySon

committed

Add missing built-in variable 'ustackdepth'. See ustackdepth patch

StaceySon

StaceySon

committed

Add missing built-in variable 'ucaller'. See ucaller patch

StaceySon

committed

Get uaddr(), ufunc(), umod(), and usym() action funtions working.

StaceySon

StaceySon

committed

Fix prochandler() in dtrace.c so that 'dtrace -c' works correctly. See prochandler preliminary patch

StaceySon

RyanStone, MarkJohnston

committed

SDT provider support for kernel modules. Reported by np@.

StaceySon

AndriyGapon

committed

DTrace is missing symbol info for kernel modules. Reported by np@.

PedroGiffuni

The DTrace userland tool has to run as root: it would be beneficial to have it use capsicum(4).

MarkJohnston

Fix problems with lockstat. It basically works, but there are problems. See avg's post. Also go through all the examples in the illumos lockstat(1) man page and fix them for FreeBSD; many of them are omitted from the FreeBSD lockstat(1) man page because they don't work properly. Also see PR 166925.

MarkJohnston

MarkJohnston

wip

Get libproc to look up symbols through a .gnu_debuglink ELF section, so that userland DTrace works properly with WITH_DEBUG_FILES.

MarkJohnston

dtrace(1) apparently has various troubles when run within in a jail.

MarkJohnston

MarkJohnston

wip

Get the DTrace test suite down to 0 failures. On my machine it's currently at 948/999 tests passing. Many of the failing tests are for userland DTrace. I've also fixed some test issues caused by various Solarisms. Also find a good place to add regression tests for issues found in FreeBSD.

MarkJohnston

MarkJohnston

wip

Port the cpc provider to FreeBSD, or implement something similar.

MarkJohnston

There are a bunch of ports that have USDT probes that aren't enabled on FreeBSD. Find them and add support. An easy place to start is tcl, a less easy place to start is perl, and a less less easy place to start is openJDK. Email markj@freebsd.org for the first two, I've made some progress on them already.

MarkJohnston

Submit DTrace patches back to illumos. There are some bug fixes in our DTrace implementation that are not specific to FreeBSD. They are minor for the most part, but should be upstreamed. Maybe the illumos people don't mind having #ifdef FreeBSD in their code? :)

MarkJohnston

Improve documentation. I would very much like to see man pages for each of our SDT providers. Here is a proposed example.

MarkJohnston

plockstat provider

MarkJohnston

Fix dtrace kernel module unloads. At the moment this frequently causes kernel crashes, making it difficult to test changes to the DTrace kernel code.

MarkJohnston

Fix dtrace -h and dtrace -G to not depend on dtrace.ko being loaded (I'm pretty sure there's no reason for this). Otherwise ports with DTrace probes can't be built as non-root or without loading the modules first.

HowardSu

HowardSu

wip

Port dtrace to arm platform. based on the early work done by gonzo@

review = needs code review, wip = "work in progress"

Available patches

References


CategoryDTrace CategoryTODO

DTraceTODO (last edited 2014-04-16 02:58:46 by MarkJohnston)