On 7/27/23 17:55, Qi Zheng wrote:

quoted

quoted

          goto err;
      }
  +    zmd->mblk_shrinker->count_objects = dmz_mblock_shrinker_count;
+    zmd->mblk_shrinker->scan_objects = dmz_mblock_shrinker_scan;
+    zmd->mblk_shrinker->seeks = DEFAULT_SEEKS;
+    zmd->mblk_shrinker->private_data = zmd;
+
+    shrinker_register(zmd->mblk_shrinker);

I fail to see how this new shrinker API is better... Why isn't there a
shrinker_alloc_and_register() function ? That would avoid adding all this code
all over the place as the new API call would be very similar to the current
shrinker_register() call with static allocation.

In some registration scenarios, memory needs to be allocated in advance.
So we continue to use the previous prealloc/register_prepared()
algorithm. The shrinker_alloc_and_register() is just a helper function
that combines the two, and this increases the number of APIs that
shrinker exposes to the outside, so I choose not to add this helper.

And that results in more code in many places instead of less code + a simple
inline helper in the shrinker header file... So not adding that super simple
helper is not exactly the best choice in my opinion.

-- 
Damien Le Moal
Western Digital Research