Re: [PATCH 3/3] relay: Add buffer-only channels; useful for early logging.

On Sat, 5 Jul 2008 07:14:01 +0300 Eduard - Gabriel Munteanu [off-list ref] wrote:

On Wed, 2 Jul 2008 23:06:36 -0700
Andrew Morton [off-list ref] wrote:
 

quoted

This breaks on sparc64.

quoted

+			err = smp_call_function_single(i,
+
__relay_set_buf_dentry,
+						       &disp, 0,
1);

Because that ain't implemented.

There's a call in net/iucv/iucv.c, but that's s390-only.

There's a call in virt/kvm/kvm_main.c.

There's a call in kernel/time/tick-broadcast.c, so I assume that the
intersection between CONFIG_GENERIC_CLOCKEVENTS_BROADCAST and
non-smp_call_function_single() architectures is presently empty.

Hi,

I'm not sure what I should do.

Nothing, I'd suggest.  I think that all architectures should implement
smp_call_function_single().  You can have a shot at doing that if you
like, but the implementations will need to be reviewed and merged by
the relevant architectures maintainers.  (That's why I snuck linux-arch
into the cc list last time).

Maybe disable relay_late_setup_files()
on sparc64, with an empty inline?
 

quoted

I guess all SMP-capable architectures should now implement this,
please.  It is presently defined on all architectures for CONFIG_SMP=n
and it is declared in include/linux/smp.h.

sparc64 seems to have smp_call_function_mask(). If we have the generic
kernel/smp.c in linux-next or -mmotm, then this will define
smp_call_function_single() to call smp_call_function_mask().

Is there anything I can do regarding this patch? Does it work since
kernel/smp.c reappeared?

Nope:

y:/usr/src/25> grep USE_GENERIC_SMP_HELPERS arch/*/Kconfig
arch/alpha/Kconfig:     select USE_GENERIC_SMP_HELPERS
arch/arm/Kconfig:       select USE_GENERIC_SMP_HELPERS
arch/ia64/Kconfig:      select USE_GENERIC_SMP_HELPERS
arch/m32r/Kconfig:      select USE_GENERIC_SMP_HELPERS
arch/mips/Kconfig:      select USE_GENERIC_SMP_HELPERS
arch/parisc/Kconfig:    select USE_GENERIC_SMP_HELPERS
arch/powerpc/Kconfig:   select USE_GENERIC_SMP_HELPERS if SMP
arch/sh/Kconfig:        select USE_GENERIC_SMP_HELPERS
arch/x86/Kconfig:       select USE_GENERIC_SMP_HELPERS

It would help if you could check to see which architectures need work
and then perhaps propose patches.  If not, well, 2.6.27-rc1 will be
broken on some architectures on some configs and people will have a
couple of months to unbreak it.  Not a big problem, I expect.