These are things that I would like to eventually get done/fix. Please mail me if you'd like to work on them.

Merge fdescfs into devfs.

• needed for fexecve()+shebang
• expected by lots of third-party software
• default in other unix-like kernels
• considerations:
  • needs to appear in jails by default as well
  • need to sort out Capsicum integration

Early microcode loading on AMD

• lacking a convenient test system

TRIM for swap devices

• interrogate swap GEOM for candelete capability
• dispatch TRIMs asynchronously from swp_pager_freeswapspace()
• Doug is working on this: https://reviews.freebsd.org/D20863

IPv6 netdump(4)

• need to use Neighbour Discovery to find the first-hop router

Kernel dump regression testing

• doable with bhyve and expect after r346550

lockmgr(9), rmlock(9) and epoch(9) integration into lockstat

devvn_refthread() is a scalability bottleneck with many bhyve VMs or many vCPUs

Implement Linux's MADV_DONTNEED semantics

• Frees pages (and backing swap) if the object backing the entry is OBJT_DEFAULT or _ANON and OBJ_ONEMAPPING. Is a correct implementation required to do anything else?
• Maybe implement it using msync() instead of madvise() since the latter is advisory and should stay that way. Maybe MS_PURGE, after illumos' MADV_PURGE.

elftoolchain addr2line is extremely slow

• Try feeding it a list of addresses by piping them into addr2line -afi -e kernel.debug
• Compare with GNU addr2line and weep

sendmail hangs on boot if the hostname contains a single component

Make SCTP a loadable module and remove it from GENERIC

• It presents a large attack surface but is not widely used

Better VM statistics

• Per-domain stats in vmstat -s output
• Add counters for the various branches in page daemon scanning (e.g., how many times did we skip a busy page?)
• Measure internal fragmentation in UMA zones
• Page table and PV chunk memory usage

Valgrind regression tests

• https://github.com/FreeBSDFoundation/valgrind/tree/freebsd.20190314
• sh autogen.sh && ./configure && gmake && gmake regtest
• Lots of tests still failing; syscall wrappers need to be updated

syzbot reports

• https://syzkaller.appspot.com/freebsd

Capsicumizing the base system

• False-positive WITNESS warnings. These confuse automation and new users alike.
• stack_chk_init: WARNING: Initializing stack protection with non-random cookies!
  • I don't know whether this is important or how to fix it.
• WARNING: attempt to domain_add(%s) after domainfinalize()
  • Printed when bluetooth modules are auto-loaded during boot

Set a Kyua configuration variable from the command line

• kyua -v test_suites.FreeBSD.allow_sysctl_side_effects=1 test