Download raw body.
Mostly-Inverted CPU-Core ordering
On Sat, Mar 07, 2026 at 09:37:17AM +0100, Stefan Fritsch wrote:
> On Fri, 6 Mar 2026, Theo de Raadt wrote:
>
> > > Not my area. Should this be committed?
> >
> > I am not sure why it hasn't been.
> >
>
> AFAIK, it has only been tested on amd64, arm64, i386. The other
> architectures need testing. And an ok would be nice.
Apologies for the delay, Stefan!
I guess you could have committed the diffs for architectures that have
been tested already. Regarding the remaining architectures:
- alpha: I'll try to test this with miod's help during this week-end
- arm: no MP so no meaningful test possible
- mips64: can't test right now but at least visa/kirill/kn have such hw
- riscv64: GENERIC builds, GENERIC.MP runs (hw: Hifive Unmatched)
All your changes look fine to me. ok jca@ for the architectures that
have been tested and arm. ok for the rest when you get basic testing.
cc'ing the relevant folks, here's the second/latest diff with
!MULTIPROCESSOR fixes, for convenience.
diff --git a/sys/arch/alpha/alpha/cpu.c b/sys/arch/alpha/alpha/cpu.c
index 23b25c94219..38425f1d905 100644
--- a/sys/arch/alpha/alpha/cpu.c
+++ b/sys/arch/alpha/alpha/cpu.c
@@ -419,7 +419,7 @@ cpu_announce_extensions(struct cpu_info *ci)
void
cpu_boot_secondary_processors(void)
{
- struct cpu_info *ci;
+ struct cpu_info *ci, *ci_last;
u_long i;
for (i = 0; i < ALPHA_MAXPROCS; i++) {
@@ -434,8 +434,10 @@ cpu_boot_secondary_processors(void)
/*
* Link the processor into the list, and launch it.
*/
- ci->ci_next = cpu_info_list->ci_next;
- cpu_info_list->ci_next = ci;
+ ci_last = cpu_info_list;
+ while (ci_last->ci_next != NULL)
+ ci_last = ci_last->ci_next;
+ ci_last->ci_next = ci;
atomic_setbits_ulong(&ci->ci_flags, CPUF_RUNNING);
atomic_setbits_ulong(&cpus_running, (1UL << i));
ncpus++;
diff --git a/sys/arch/amd64/amd64/cpu.c b/sys/arch/amd64/amd64/cpu.c
index 18cfb8d6377..4d56f320c33 100644
--- a/sys/arch/amd64/amd64/cpu.c
+++ b/sys/arch/amd64/amd64/cpu.c
@@ -729,8 +729,11 @@ cpu_attach(struct device *parent, struct device *self, void *aux)
sched_init_cpu(ci);
ncpus++;
if (ci->ci_flags & CPUF_PRESENT) {
- ci->ci_next = cpu_info_list->ci_next;
- cpu_info_list->ci_next = ci;
+ struct cpu_info *ci_last = cpu_info_list;
+
+ while (ci_last->ci_next != NULL)
+ ci_last = ci_last->ci_next;
+ ci_last->ci_next = ci;
}
#else
printf("%s: not started\n", sc->sc_dev.dv_xname);
diff --git a/sys/arch/arm/arm/cpu.c b/sys/arch/arm/arm/cpu.c
index f51404f73be..005211ba35f 100644
--- a/sys/arch/arm/arm/cpu.c
+++ b/sys/arch/arm/arm/cpu.c
@@ -354,10 +354,14 @@ cpu_attach(struct device *parent, struct device *dev, void *aux)
ci = &cpu_info_primary;
ci->ci_flags |= CPUF_RUNNING | CPUF_PRESENT | CPUF_PRIMARY;
} else {
+ struct cpu_info *ci_last;
+
ci = malloc(sizeof(*ci), M_DEVBUF, M_WAITOK | M_ZERO);
cpu_info[dev->dv_unit] = ci;
- ci->ci_next = cpu_info_list->ci_next;
- cpu_info_list->ci_next = ci;
+ ci_last = cpu_info_list;
+ while (ci_last->ci_next != NULL)
+ ci_last = ci_last->ci_next;
+ ci_last->ci_next = ci;
ci->ci_flags |= CPUF_AP;
ncpus++;
}
diff --git a/sys/arch/arm64/arm64/cpu.c b/sys/arch/arm64/arm64/cpu.c
index f9784e432db..8f59fc03e0f 100644
--- a/sys/arch/arm64/arm64/cpu.c
+++ b/sys/arch/arm64/arm64/cpu.c
@@ -1481,6 +1481,7 @@ cpu_attach(struct device *parent, struct device *dev, void *aux)
struct cpu_info *ci;
void *kstack;
#ifdef MULTIPROCESSOR
+ struct cpu_info *ci_last;
uint64_t mpidr = READ_SPECIALREG(mpidr_el1);
#endif
uint32_t opp;
@@ -1494,8 +1495,10 @@ cpu_attach(struct device *parent, struct device *dev, void *aux)
} else {
ci = malloc(sizeof(*ci), M_DEVBUF, M_WAITOK | M_ZERO);
cpu_info[dev->dv_unit] = ci;
- ci->ci_next = cpu_info_list->ci_next;
- cpu_info_list->ci_next = ci;
+ ci_last = cpu_info_list;
+ while (ci_last->ci_next != NULL)
+ ci_last = ci_last->ci_next;
+ ci_last->ci_next = ci;
ci->ci_flags |= CPUF_AP;
ncpus++;
}
diff --git a/sys/arch/i386/i386/cpu.c b/sys/arch/i386/i386/cpu.c
index c5f18dd4433..e3b4d7cc589 100644
--- a/sys/arch/i386/i386/cpu.c
+++ b/sys/arch/i386/i386/cpu.c
@@ -234,6 +234,7 @@ cpu_attach(struct device *parent, struct device *self, void *aux)
struct cpu_info *ci;
#ifdef MULTIPROCESSOR
+ struct cpu_info *ci_last;
int cpunum = sc->sc_dev.dv_unit;
vaddr_t kstack;
struct pcb *pcb;
@@ -365,8 +366,10 @@ cpu_attach(struct device *parent, struct device *self, void *aux)
identifycpu(ci);
clockqueue_init(&ci->ci_queue);
sched_init_cpu(ci);
- ci->ci_next = cpu_info_list->ci_next;
- cpu_info_list->ci_next = ci;
+ ci_last = cpu_info_list;
+ while (ci_last->ci_next != NULL)
+ ci_last = ci_last->ci_next;
+ ci_last->ci_next = ci;
ncpus++;
#endif
break;
diff --git a/sys/arch/mips64/mips64/cpu.c b/sys/arch/mips64/mips64/cpu.c
index 040669d397b..fe45ce0970c 100644
--- a/sys/arch/mips64/mips64/cpu.c
+++ b/sys/arch/mips64/mips64/cpu.c
@@ -95,9 +95,13 @@ cpuattach(struct device *parent, struct device *dev, void *aux)
panic("unable to allocate cpu_info");
}
} else {
+ struct cpu_info *ci_last;
+
ci = &cpu_info_secondaries[cpuno - 1];
- ci->ci_next = cpu_info_list->ci_next;
- cpu_info_list->ci_next = ci;
+ ci_last = cpu_info_list;
+ while (ci_last->ci_next != NULL)
+ ci_last = ci_last->ci_next;
+ ci_last->ci_next = ci;
ci->ci_flags |= CPUF_PRESENT;
}
#else
diff --git a/sys/arch/riscv64/riscv64/cpu.c b/sys/arch/riscv64/riscv64/cpu.c
index e8400d4eed3..1c2c2a1341c 100644
--- a/sys/arch/riscv64/riscv64/cpu.c
+++ b/sys/arch/riscv64/riscv64/cpu.c
@@ -195,10 +195,14 @@ cpu_attach(struct device *parent, struct device *dev, void *aux)
ci->ci_flags |= CPUF_RUNNING | CPUF_PRESENT | CPUF_PRIMARY;
csr_set(sie, SIE_SSIE);
} else {
+ struct cpu_info *ci_last;
+
ci = malloc(sizeof(*ci), M_DEVBUF, M_WAITOK | M_ZERO);
cpu_info[dev->dv_unit] = ci;
- ci->ci_next = cpu_info_list->ci_next;
- cpu_info_list->ci_next = ci;
+ ci_last = cpu_info_list;
+ while (ci_last->ci_next != NULL)
+ ci_last = ci_last->ci_next;
+ ci_last->ci_next = ci;
ci->ci_flags |= CPUF_AP;
ncpus++;
}
--
jca
Mostly-Inverted CPU-Core ordering