MFC r298333:
r298333 (by cem):

Make Racct macro slightly more gracious given RACCT_UNDEFINED

rctl_string_to_rule could previously index below the zeroth element of
racct_types via the macro. Maybe it shouldn't use the macro on
RACCT_UNDEFINED. But given every other RACCT_ definition is non-negative, it
seems pretty easy to foot-shoot this one without the check.

CID: 1305574

MFC r282213:

Add kern.racct.enable tunable and RACCT_DISABLED config option.
The point of this is to be able to add RACCT (with RACCT_DISABLED)
to GENERIC, to avoid having to rebuild the kernel to use rctl(8).

MFC r282901:

Build GENERIC with RACCT/RCTL support by default. Note that it still
needs to be enabled by adding "kern.racct.enable=1" to /boot/loader.conf.

Note those two are MFC-ed together, because the latter one changes the
name of RACCT_DISABLED option to RACCT_DEFAULT_TO_DISABLED. Should have
committed the renaming separately...

Relnotes: yes
Sponsored by: The FreeBSD Foundation

MFC r282213:

Add kern.racct.enable tunable and RACCT_DISABLED config option.
The point of this is to be able to add RACCT (with RACCT_DISABLED)
to GENERIC, to avoid having to rebuild the kernel to use rctl(8).

MFC r282901:

Build GENERIC with RACCT/RCTL support by default. Note that it still
needs to be enabled by adding "kern.racct.enable=1" to /boot/loader.conf.

Note those two are MFC-ed together, because the latter one changes the
name of RACCT_DISABLED option to RACCT_DEFAULT_TO_DISABLED. Should have
committed the renaming separately...

Relnotes: yes
Sponsored by: The FreeBSD Foundation