On Mon, 14 May 2007, Peter Zijlstra wrote:

> Index: linux-2.6-git/include/linux/slub_def.h
> ===================================================================
> --- linux-2.6-git.orig/include/linux/slub_def.h
> +++ linux-2.6-git/include/linux/slub_def.h
> @@ -52,6 +52,7 @@ struct kmem_cache {
>       struct kmem_cache_node *node[MAX_NUMNODES];
>  #endif
>       struct page *cpu_slab[NR_CPUS];
> +     int rank;
>  };

Ranks as part of the kmem_cache structure? I thought this is a temporary 
thing?

>   * Lock order:
> @@ -961,6 +962,8 @@ static struct page *allocate_slab(struct
>       if (!page)
>               return NULL;
>  
> +     s->rank = page->index;
> +

Argh.... Setting a cache structure field from a page struct field? What 
about concurrency?

> @@ -1371,8 +1376,12 @@ static void *__slab_alloc(struct kmem_ca
>               gfp_t gfpflags, int node, void *addr, struct page *page)
>  {
>       void **object;
> -     int cpu = smp_processor_id();
> +     int cpu;
> +
> +     if (page == FORCE_PAGE)
> +             goto force_new;
>  
> +     cpu = smp_processor_id();
>       if (!page)
>               goto new_slab;
>  
> @@ -1405,6 +1414,7 @@ have_slab:
>               goto load_freelist;
>       }
>  
> +force_new:
>       page = new_slab(s, gfpflags, node);
>       if (page) {
>               cpu = smp_processor_id();
> @@ -1465,15 +1475,22 @@ static void __always_inline *slab_alloc(
>       struct page *page;
>       void **object;
>       unsigned long flags;
> +     int rank = slab_alloc_rank(gfpflags);
>  
>       local_irq_save(flags);
> +     if (slab_insufficient_rank(s, rank)) {
> +             page = FORCE_PAGE;
> +             goto force_alloc;
> +     }
> +
>       page = s->cpu_slab[smp_processor_id()];
>       if (unlikely(!page || !page->lockless_freelist ||
> -                     (node != -1 && page_to_nid(page) != node)))
> +                     (node != -1 && page_to_nid(page) != node))) {
>  
> +force_alloc:
>               object = __slab_alloc(s, gfpflags, node, addr, page);
>  
> -     else {
> +     } else {
>               object = page->lockless_freelist;
>               page->lockless_freelist = object[page->offset];
>       }

This is the hot path. No modifications please.


-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/

Reply via email to