Export kernel malloc sizes

[mjg]

Summary

Nothing exports zones as used by malloc and vmstat blindly assumes it is just powers of 2.

This is a prerequisite to add any extra zones to malloc, but it stands as an improvement on its own. The current dependency is a bug.

I think the patch in the current form is committable (modulo perhaps some names).

Test Plan

Added extra zones:

diff --git a/sys/kern/kern_malloc.c b/sys/kern/kern_malloc.c
index b7d7e0c2d4b..a981ff0d9e4 100644
--- a/sys/kern/kern_malloc.c
+++ b/sys/kern/kern_malloc.c
@@ -158,7 +158,11 @@ struct {
 } kmemzones[] = {
        {16, "16", },
        {32, "32", },
+       {48, "48", },
        {64, "64", },
+       {80, "80", },
+       {96, "96", },
+       {112, "112", },
        {128, "128", },
        {256, "256", },
        {512, "512", },

And a toy malloc type. Confirmed the sizes get reported and the allocation done with toy type is correctly reported.

vmstat -m and vmstat -M /dev/mem -m agree on the state.

[markj]

sys/kern/kern_malloc.c

231 ↗

(On Diff #78985)

Duplicated description.

usr.bin/vmstat/vmstat.c

1423 ↗

(On Diff #78985)

This won't work if running against a vmcore.

[mjg]

Rework the patch.

[markj]

lib/libmemstat/memstat_malloc.c

458 ↗

(On Diff #78999)

These lines are too long.

541 ↗

(On Diff #78999)

It should probably be ((uint64_t)1 << n).