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

[Andrew Morton <akpm@linux-foundation.org>]

On Mon, 23 Jun 2008 15:31:04 +0300 Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro> wrote:

> Allows one to create and use a channel with no associated files. Files
> can be initialized later. This is useful in scenarios such as logging
> in early code, before VFS is up. Therefore, such channels can be
> created and used as soon as kmem_cache_init() completed.
> 
> This is needed by kmemtrace to do tracing in early kernel code.

This breaks on sparc64.

> +			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.


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.