not exactly a ray of sunshine with new SPARC hardware

[Dennis Clarke <dclarke%blastwave.org@localhost>]

On 10/25/26 12:27, Tony Rodriguez wrote:
> > On Oct 25, 2026, at 7:10 AM, Dennis Clarke <dclarke%blastwave.org@localhost> wrote:
> >
> > On 10/25/26 09:39, Palle Lyckegaard wrote:
> > > > On Sun, 25 Oct 2026, Dennis Clarke wrote:
> > > > I took a break from the NetBSD experiment and moved over to Gentoo
> > > > Linux. Well guess what? It makes a bit of progress and then just locks
> > > > up as frozen. Over and over I would reboot and go through the motions
> > > > and then Linux would just freeze. 

> Regarding Linux, once gain many of the patches for sparc64 should be in
 the Linux 7.4 kernel...
Yes, you know far better than I :

 
https://lore.kernel.org/lkml/20250724-vdso-sparc64-generic-2-v1-0-e376a3bd24d1%linutronix.de@localhost/

However I believe none of it because it clearly says :

    "Only tested on QEMU."

With both NetBSD and Linux people are plowing a field that will bring 
forth no crop. The vast differences between the older SUN4v hardware
and the new S7 and T7 and M8 are vast. So vast that only a manufacturer
could implement the required kernel level code. I have done a few tests
in the last year and they ALL fail. Either instantly or after only a few
hours of time wasted. Every time. No exceptions.

The problems are myriad. Virtual disk layers are a disaster. Compute
load causes virtual memory page faults and then those turn into a kernel
panic or the LDOM just hangs. If the hypervisor tries to flush the
cache or Translation Lookaside Buffer? ( I hd to research this one) on
the other vCPUs then the thing goes bonkers. We get a race condition
and the cpu cores wait for each other and whammo it all locks up. Dead.

The situation is a bloody mess on hardware that no one owns anyways. The
old SPARC machines and the old Niagara stuff likely works okay. However
the new gear? Not unless a manufacturer steps up to the plate and is
highly motivated. We are far far better to just get the IBM POWER9 or
POWER10 servers and then everything works.[1]

--
--
Dennis Clarke
RISC-V/SPARC/PPC/ARM/CISC
UNIX and Linux spoken

[1] I made no mention of :
 
https://www.kernel.org/doc/html/v7.3/arch/sparc/oradax/oracle-dax.html
    That seems to be a trivial bit from ORACLE to allow access to the
    snazzy Data Analytics Accelerator ( DAX ). This is trivial when we
    have Solaris 11.4 :

#include <stdio.h>
#include <stdlib.h>
#include <stdint.h>
#include <dax.h>

int main() {

    dax_context_t *ctx = NULL;
    dax_status_t status;
    uint32_t api_version = 0;

    printf("INFO : initialize native SPARC DAX context\n");

    /* TODO : see dax_thread_init(3DAX) for all return values */
    status = dax_thread_init(1, 1, 0, NULL, &ctx);

    if (status != DAX_SUCCESS) {
        fprintf(stderr, "FAIL : initialize DAX thread context\n");
        fprintf(stderr, "     : please verify DAX module is loaded\n");
        return EXIT_FAILURE;
    }
    printf("INFO : initialized DAX context success\n");

    status = dax_version(ctx, &api_version);
    if (status == DAX_SUCCESS) {
        printf("INFO : libdax API version v%u\n", api_version);
    } else {
        fprintf(stderr,"WARN : fail query hardware version property\n");
        fprintf(stderr,"     : status: %d\n", status);
    }

    /* Clean up the context allocation and release
     * the hardware thread queue
     */
    printf("INFO : releasing DAX hardware context\n");
    dax_thread_fini(ctx);

    printf("INFO : DAX hardware working\n");
    return EXIT_SUCCESS;

}

neptune $ echo $CC
/opt/developerstudio12.6/bin/cc
neptune $ echo $CFLAGS
-m64 -xtarget=S7 -xcache=16/32/4/8:256/64/8/16:8192/64/8/32 -g -xO0 -mc 
-xs -errfmt=error -erroff=%none -errshort=full -errtags=yes 
-errwarn=%none -ftrap=%none -xbuiltin=%none -xildoff -xlibmieee 
-xstrconst -xcode=pic32 -xmemalign=8s -xnolibmil -xunroll=1 -xdepend 
-xregs=no%appl -xdebugformat=dwarf
neptune $ echo $CPPFLAGS
-D_LARGEFILE64_SOURCE -D_FILE_OFFSET_BITS=64
neptune $

neptune $ $CC $CFLAGS $CPPFLAGS -o dax dax.c -ldax
neptune $
neptune $ ./dax
INFO : initialize native SPARC DAX context
INFO : initialized DAX context success
INFO : libdax API version v1
INFO : releasing DAX hardware context
INFO : DAX hardware working
neptune $
neptune $ uname -a
SunOS neptune 5.11 11.4.90.212.0 sun4v sparc sun4v non-virtualized
neptune $

I have no idea what you would get with Linux. Any BSD? nope. good luck.