[Crash-utility] More fixes for kmem on slabs

[Bob Montgomery]

On Thu, 2012-02-09 at 14:08 -0500, Dave Anderson wrote:

> How's this work for you?  (patch also attached)
> 
> --- crash-6.0.3/memory.c.orig
> +++ crash-6.0.3/memory.c
> @@ -7977,14 +7977,32 @@ kmem_cache_downsize(void)
>         char *cache_buf;
>         uint buffer_size; 
>         int nr_node_ids;
> +       int nr_cpu_ids;
>  
>         if ((THIS_KERNEL_VERSION < LINUX(2,6,22)) ||
> -           (vt->flags & NODELISTS_IS_PTR) ||
>             !(vt->flags & PERCPU_KMALLOC_V2_NODES) ||
>             !kernel_symbol_exists("cache_cache") ||
>             !MEMBER_EXISTS("kmem_cache", "buffer_size"))
>                 return;
>  
> +       if (vt->flags & NODELISTS_IS_PTR) {
> +               /* 
> +                * kmem_cache.array[] is actually sized by 
> +                * the number of cpus; real value is nr_cpu_ids, 
> +                * but fallback is kt->cpus.
> +                */
> +               if (kernel_symbol_exists("nr_cpu_ids"))
> +                       get_symbol_data("nr_cpu_ids", sizeof(int), 
> +                               &nr_cpu_ids);
> +               else 
> +                       nr_cpu_ids = kt->cpus;
> +
> +               ARRAY_LENGTH(kmem_cache_s_array) = nr_cpu_ids;
> +               ASSIGN_SIZE(kmem_cache_s) = OFFSET(kmem_cache_s_array) +
> +                       sizeof(ulong) * nr_cpu_ids;
> +               return;
> +       }
> +
>         cache_buf = GETBUF(SIZE(kmem_cache_s));
>  
>         if (!readmem(symbol_value("cache_cache"), KVADDR, cache_buf, 
> 
> Dave
> 

Looks good.  Identical answers to my original patch on my two 3.1.4 test
cases, and a cleaner solution.  

Thanks,
Bob Montgomery