[anolis-intel-cloud:devel-6.6 2/2] mm/balloon_compaction.c:199: warning: Function parameter or member 'first_page' not described in 'balloon_page_list_dequeue_cont'

[kernel test robot <lkp@intel.com>]

tree:   https://gitee.com/anolis/intel-cloud-kernel.git devel-6.6
head:   f64b5635bc6da0e12f72f202d7ac1b5bb5457209
commit: 1f23c7bc1279ef309af72e4ee3a93f78b9b7a05e [2/2] anolis: virtio_balloon: Add deflate_cont_vq to deflate continuous pages
config: x86_64-anolis-intel-cloud-devel-6.6 (https://download.01.org/0day-ci/archive/20260106/202601060008.1BRGbier-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.4.0-5) 12.4.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20260106/202601060008.1BRGbier-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202601060008.1BRGbier-lkp@intel.com/

All warnings (new ones prefixed by >>):

>> mm/balloon_compaction.c:199: warning: Function parameter or member 'first_page' not described in 'balloon_page_list_dequeue_cont'


vim +199 mm/balloon_compaction.c

   177	
   178	/**
   179	 * balloon_page_list_dequeue_cont() - removes continuous pages from balloon's page list
   180	 *				      and returns a list of the continuous pages.
   181	 * @b_dev_info: balloon device decriptor where we will grab a page from.
   182	 * @pages: pointer to the list of pages that would be returned to the caller.
   183	 * @max_req_pages: max number of requested pages.
   184	 *
   185	 * Driver must call this function to properly de-allocate a previous enlisted
   186	 * balloon pages before definitively releasing it back to the guest system.
   187	 * This function tries to remove @max_req_pages continuous pages from the ballooned
   188	 * pages and return them to the caller in the @pages list.
   189	 *
   190	 * Note that this function may fail to dequeue some pages even if the balloon
   191	 * isn't empty - since the page list can be temporarily empty due to compaction
   192	 * of isolated pages.
   193	 *
   194	 * Return: number of pages that were added to the @pages list.
   195	 */
   196	size_t balloon_page_list_dequeue_cont(struct balloon_dev_info *b_dev_info,
   197					      struct list_head *pages, struct page **first_page,
   198					      size_t max_req_pages)
 > 199	{
   200		struct page *page, *tmp;
   201		unsigned long flags, tail_pfn;
   202		size_t n_pages = 0;
   203		bool got_first = false;
   204	
   205		spin_lock_irqsave(&b_dev_info->pages_lock, flags);
   206		list_for_each_entry_safe_reverse(page, tmp, &b_dev_info->pages, lru) {
   207			unsigned long pfn;
   208	
   209			if (n_pages == max_req_pages)
   210				break;
   211	
   212			pfn = page_to_pfn(page);
   213	
   214			if (got_first && pfn != tail_pfn + 1)
   215				break;
   216	
   217			/*
   218			 * Block others from accessing the 'page' while we get around to
   219			 * establishing additional references and preparing the 'page'
   220			 * to be released by the balloon driver.
   221			 */
   222			if (!trylock_page(page)) {
   223				if (!got_first)
   224					continue;
   225				else
   226					break;
   227			}
   228	
   229			if (IS_ENABLED(CONFIG_BALLOON_COMPACTION) && PageIsolated(page)) {
   230				/* raced with isolation */
   231				unlock_page(page);
   232				if (!got_first)
   233					continue;
   234				else
   235					break;
   236			}
   237			balloon_page_delete(page);
   238			__count_vm_event(BALLOON_DEFLATE);
   239			list_add(&page->lru, pages);
   240			unlock_page(page);
   241			n_pages++;
   242			tail_pfn = pfn;
   243			if (!got_first) {
   244				got_first = true;
   245				*first_page = page;
   246			}
   247		}
   248		spin_unlock_irqrestore(&b_dev_info->pages_lock, flags);
   249	
   250		return n_pages;
   251	}
   252	EXPORT_SYMBOL_GPL(balloon_page_list_dequeue_cont);
   253	

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki