Re: [RFC v1 05/14] bus1: util - pool utility library

[Peter Zijlstra]

On Wed, Oct 26, 2016 at 09:18:01PM +0200, David Herrmann wrote:

All small nits..

> +void bus1_pool_deinit(struct bus1_pool *pool)
> +{
> +     struct bus1_pool_slice *slice;
> +
> +     if (!pool || !pool->f)
> +             return;
> +
> +     while ((slice = list_first_entry_or_null(&pool->slices,
> +                                              struct bus1_pool_slice,
> +                                              entry))) {
> +             WARN_ON(slice->ref_kernel);
> +             list_del(&slice->entry);
> +             bus1_pool_slice_free(slice);
> +     }

I prefer to write that loop like:

        while (!list_empty(&pool->slices)) {
                slice = list_first_entry(&pool->slices, struct bus1_pool_slice, 
entry);
                list_del(&slice->entry);

                // ...
        }



> +static void bus1_pool_free(struct bus1_pool *pool,
> +                        struct bus1_pool_slice *slice)
> +{
> +     struct bus1_pool_slice *ps;
> +
> +     /* don't free the slice if either has a reference */
> +     if (slice->ref_kernel || slice->ref_user || WARN_ON(slice->free))
> +             return;
> +
> +     /*
> +      * To release a pool-slice, we first drop it from the busy-tree, then
> +      * merge it with possible previous/following free slices and re-add it
> +      * to the free-tree.
> +      */
> +
> +     rb_erase(&slice->rb, &pool->slices_busy);
> +
> +     if (!WARN_ON(slice->size > pool->allocated_size))
> +             pool->allocated_size -= slice->size;
> +
> +     if (pool->slices.next != &slice->entry) {
> +             ps = container_of(slice->entry.prev, struct bus1_pool_slice,
> +                               entry);

                ps = list_prev_entry(slice, entry);

> +             if (ps->free) {
> +                     rb_erase(&ps->rb, &pool->slices_free);
> +                     list_del(&slice->entry);
> +                     ps->size += slice->size;
> +                     bus1_pool_slice_free(slice);
> +                     slice = ps; /* switch to previous slice */
> +             }
> +     }
> +
> +     if (pool->slices.prev != &slice->entry) {
> +             ps = container_of(slice->entry.next, struct bus1_pool_slice,
> +                               entry);

                ps = list_next_entry(slice, entry);

> +             if (ps->free) {
> +                     rb_erase(&ps->rb, &pool->slices_free);
> +                     list_del(&ps->entry);
> +                     slice->size += ps->size;
> +                     bus1_pool_slice_free(ps);
> +             }
> +     }
> +
> +     slice->free = true;
> +     bus1_pool_slice_link_free(slice, pool);
> +}