amd64/87112: Boot problems on a 16 processor AMD64 compatible machine

Attila Nagy bra at
Sat Oct 8 02:00:30 PDT 2005

>Number:         87112
>Category:       amd64
>Synopsis:       Boot problems on a 16 processor AMD64 compatible machine
>Confidential:   no
>Severity:       serious
>Priority:       low
>Responsible:    freebsd-amd64
>State:          open
>Class:          change-request
>Submitter-Id:   current-users
>Arrival-Date:   Sat Oct 08 09:00:29 GMT 2005
>Originator:     Attila Nagy
>Release:        7-current
Not available
On a 16 processor/16 GB RAM AMD64 compatible machine FreeBSD halts with "Too many segments in the physical address map, giving up".

I don't know whether it's general, or only limited to this machine, but trying to boot FreeBSD with 16 processors could trigger the problem.
In src/sys/amd64/amd64/machdep.c:
-#define PHYSMAP_SIZE    (2 * 8)
+#define PHYSMAP_SIZE    (2 * 16)

After this:
FreeBSD/SMP: Multiprocessor System Detected: 16 CPUs
 cpu0 (BSP): APIC ID:  0
 cpu1 (AP): APIC ID:  1
 cpu2 (AP): APIC ID:  2
 cpu3 (AP): APIC ID:  3
 cpu4 (AP): APIC ID:  4
 cpu5 (AP): APIC ID:  5
 cpu6 (AP): APIC ID:  6
 cpu7 (AP): APIC ID:  7
 cpu8 (AP): APIC ID:  8
 cpu9 (AP): APIC ID:  9
 cpu10 (AP): APIC ID: 10
 cpu11 (AP): APIC ID: 11
 cpu12 (AP): APIC ID: 12
 cpu13 (AP): APIC ID: 13
 cpu14 (AP): APIC ID: 14
 cpu15 (AP): APIC ID: 15

I didn't try with i386, but I guess that has the same problem.

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