[Mesa-dev] [PATCH v2 5/7] disk cache: initialize cache path and index only when used

[Emil Velikov]

On 31 January 2018 at 07:17, Tapani Pälli <tapani.palli at intel.com> wrote:
> This patch makes disk_cache initialize path and index lazily so
> that we can utilize disk_cache without a path using callback
> functionality introduced by next patch.
>
> v2: unmap mmap and destroy queue only if index_mmap exists
>
> Signed-off-by: Tapani Pälli <tapani.palli at intel.com>
> ---
>  src/util/disk_cache.c | 127 +++++++++++++++++++++++++++++++-------------------
>  1 file changed, 78 insertions(+), 49 deletions(-)
>
I'd keep the refactor (disk_cache_create -> disk_cache_path_init +
disk_cache_create) and lazy indexing separate patches.
As-is tracking all the error paths is a quite fiddly.

> @@ -999,6 +1015,11 @@ disk_cache_put(struct disk_cache *cache, const cache_key key,
>     struct disk_cache_put_job *dc_job =
>        create_put_job(cache, key, data, size, cache_item_metadata);
>
> +   /* Initialize path if not initialized yet. */
> +   if (cache->path_init_failed ||
> +       (!cache->path && !disk_cache_path_init(cache)))
> +      return;
> +
>     if (dc_job) {
>        util_queue_fence_init(&dc_job->fence);
>        util_queue_add_job(&cache->cache_queue, dc_job, &dc_job->fence,
> @@ -1173,6 +1194,9 @@ disk_cache_put_key(struct disk_cache *cache, const cache_key key)
>     int i = CPU_TO_LE32(*key_chunk) & CACHE_INDEX_KEY_MASK;
>     unsigned char *entry;
>
> +   if (!cache->path)
> +      return;
> +
Any reason why the blurb in disk_cache_put() is missing here?

>From cache_test.c POV disk_cache_put_key relied on disk_cache_has_key
being called first, although I'm not sure if that's the most robust
approach.

-Emil