svn commit: r302372 - in head/sys: amd64/include cddl/compat/opensolaris/sys dev/cpuctl i386/include kern net netinet powerpc/include powerpc/powerpc vm

[Andrew Turner]

On Wed, 6 Jul 2016 14:09:49 +0000 (UTC)
Nathan Whitehorn <nwhitehorn at FreeBSD.org> wrote:

> Author: nwhitehorn
> Date: Wed Jul  6 14:09:49 2016
> New Revision: 302372
> URL: https://svnweb.freebsd.org/changeset/base/302372
> 
> Log:
>   Replace a number of conflations of mp_ncpus and mp_maxid with either
>   mp_maxid or CPU_FOREACH() as appropriate. This fixes a number of
> places in the kernel that assumed CPU IDs are dense in [0, mp_ncpus)
> and would try, for example, to run tasks on CPUs that did not exist
> or to allocate too few buffers on systems with sparse CPU IDs in
> which there are holes in the range and mp_maxid > mp_ncpus. Such
> circumstances generally occur on systems with SMT, but on which SMT
> is disabled. This patch restores system operation at least on POWER8
> systems configured in this way. 
>   There are a number of other places in the kernel with potential
> problems in these situations, but where sparse CPU IDs are not
> currently known to occur, mostly in the ARM machine-dependent code.
> These will be fixed in a follow-up commit after the stable/11 branch.
>   
...
> Modified: head/sys/net/flowtable.c
> ==============================================================================
> --- head/sys/net/flowtable.c	Wed Jul  6 10:57:04 2016
> (r302371) +++ head/sys/net/flowtable.c	Wed Jul  6 14:09:49
> 2016	(r302372) @@ -746,7 +746,7 @@ flowtable_alloc(struct
> flowtable *ft) ft->ft_table[i] = uma_zalloc(pcpu_zone_ptr, M_WAITOK |
> M_ZERO); 
>  	ft->ft_masks = uma_zalloc(pcpu_zone_ptr, M_WAITOK);
> -	for (int i = 0; i < mp_ncpus; i++) {
> +	CPU_FOREACH(i) {

This is broken, it removed the declaration of i.

Andrew