Re: git: 4f2465260f03 - main - SYSINIT: add SI_SUB_FIRST

On Tue, 11 Aug 2026, Gleb Smirnoff wrote:

> The branch main has been updated by glebius:
>
> URL: https://cgit.FreeBSD.org/src/commit/?id=4f2465260f035fa0095e73b34a74851ef2efaa83
>
> commit 4f2465260f035fa0095e73b34a74851ef2efaa83
> Author:     Gleb Smirnoff <[email protected]>
> AuthorDate: 2026-08-11 14:40:06 +0000
> Commit:     Gleb Smirnoff <[email protected]>
> CommitDate: 2026-08-11 14:40:06 +0000
>
>    SYSINIT: add SI_SUB_FIRST
>
>    This allows to initialize mp_maxid, mp_ncpus and register APICs at the
>    most early stage, guaranteeing that those values will already be available
>    at SI_SUB_TUNABLES.
>
>    Reviewed by:            markj
>    Differential Revision:  https://reviews.freebsd.org/D58712
> ---
> sys/kern/subr_smp.c      | 2 +-
> sys/sys/kernel.h         | 1 +
> sys/x86/acpica/madt.c    | 2 +-
> sys/x86/x86/local_apic.c | 2 +-
> sys/x86/x86/mptable.c    | 3 +--
> 5 files changed, 5 insertions(+), 5 deletions(-)
>
> diff --git a/sys/kern/subr_smp.c b/sys/kern/subr_smp.c
> index dd2e829aefbf..a58a179336f3 100644
> --- a/sys/kern/subr_smp.c
> +++ b/sys/kern/subr_smp.c
> @@ -179,7 +179,7 @@ mp_setmaxid(void *dummy)
>
> 	cpusetsizemin = howmany(mp_maxid + 1, NBBY);
> }
> -SYSINIT(cpu_mp_setmaxid, SI_SUB_TUNABLES, SI_ORDER_FIRST, mp_setmaxid, NULL);
> +SYSINIT(cpu_mp_setmaxid, SI_SUB_FIRST, SI_ORDER_ANY, mp_setmaxid, NULL);
>
> /*
>  * Call the MD SMP initialization code.
> diff --git a/sys/sys/kernel.h b/sys/sys/kernel.h
> index 139a570c7ac6..2e1b1bd537cd 100644
> --- a/sys/sys/kernel.h
> +++ b/sys/sys/kernel.h
> @@ -94,6 +94,7 @@ extern volatile long ticksl;
>  */
> enum sysinit_sub_id {
> 	SI_SUB_DUMMY		= 0x0000000,	/* not executed; for linker */
> +	SI_SUB_FIRST		= 0x0600000,	/* mp_maxid, etc... */

Are we expecting a SI_SUB_PRE_FIRST one day or why did we not put it on 1 but 6?
It seems more likely there'll be something between FIRST and TUNABLE/COPYRIGHT one
day than before FIRST?

> 	SI_SUB_TUNABLES		= 0x0700000,	/* establish tunable values */
> 	SI_SUB_COPYRIGHT	= 0x0800001,	/* first use of console */
> 	SI_SUB_VM		= 0x1000000,	/* virtual memory system init */

-- 
Bjoern A. Zeeb                                                     r15:7