mempool: improve kerneldoc comments

Use proper formatting, use full sentences and reduce some verbosity in
function parameter descriptions.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Link: https://patch.msgid.link/20251113084022.1255121-4-hch@lst.de
Signed-off-by: Vlastimil Babka <vbabka@suse.cz>

Author: Christoph Hellwig

mm/mempool.c

@@ -372,18 +372,20 @@ int mempool_resize(mempool_t *pool, int new_min_nr)
 EXPORT_SYMBOL(mempool_resize);
 
 /**
- * mempool_alloc - allocate an element from a specific memory pool
- * @pool:      pointer to the memory pool which was allocated via
- *             mempool_create().
- * @gfp_mask:  the usual allocation bitmask.
+ * mempool_alloc - allocate an element from a memory pool
+ * @pool:	pointer to the memory pool
+ * @gfp_mask:	GFP_* flags.  %__GFP_ZERO is not supported.
  *
- * this function only sleeps if the alloc_fn() function sleeps or
- * returns NULL. Note that due to preallocation, this function
- * *never* fails when called from process contexts. (it might
- * fail if called from an IRQ context.)
- * Note: using __GFP_ZERO is not supported.
+ * Allocate an element from @pool.  This is done by first calling into the
+ * alloc_fn supplied at pool initialization time, and dipping into the reserved
+ * pool when alloc_fn fails to allocate an element.
  *
- * Return: pointer to the allocated element or %NULL on error.
+ * This function only sleeps if the alloc_fn callback sleeps, or when waiting
+ * for elements to become available in the pool.
+ *
+ * Return: pointer to the allocated element or %NULL when failing to allocate
+ * an element.  Allocation failure can only happen when @gfp_mask does not
+ * include %__GFP_DIRECT_RECLAIM.
  */
 void *mempool_alloc_noprof(mempool_t *pool, gfp_t gfp_mask)
 {
@@ -456,11 +458,10 @@ EXPORT_SYMBOL(mempool_alloc_noprof);
 
 /**
  * mempool_alloc_preallocated - allocate an element from preallocated elements
- *                              belonging to a specific memory pool
- * @pool:      pointer to the memory pool which was allocated via
- *             mempool_create().
+ *                              belonging to a memory pool
+ * @pool:	pointer to the memory pool
  *
- * This function is similar to mempool_alloc, but it only attempts allocating
+ * This function is similar to mempool_alloc(), but it only attempts allocating
  * an element from the preallocated elements. It does not sleep and immediately
  * returns if no preallocated elements are available.
  *
@@ -492,12 +493,14 @@ void *mempool_alloc_preallocated(mempool_t *pool)
 EXPORT_SYMBOL(mempool_alloc_preallocated);
 
 /**
- * mempool_free - return an element to the pool.
- * @element:   pool element pointer.
- * @pool:      pointer to the memory pool which was allocated via
- *             mempool_create().
+ * mempool_free - return an element to a mempool
+ * @element:	pointer to element
+ * @pool:	pointer to the memory pool
+ *
+ * Returns @element to @pool if it needs replenishing, else frees it using
+ * the free_fn callback in @pool.
  *
- * this function only sleeps if the free_fn() function sleeps.
+ * This function only sleeps if the free_fn callback sleeps.
  */
 void mempool_free(void *element, mempool_t *pool)
 {