Re: [PATCH v2 4/9] mm: vmalloc: Remove global vmap_area_root rb-tree

From: kernel test robot <lkp@intel.com>
To: "Uladzislau Rezki (Sony)" <urezki@gmail.com>,
	linux-mm@kvack.org, Andrew Morton <akpm@linux-foundation.org>
Cc: oe-kbuild-all@lists.linux.dev,
	Linux Memory Management List <linux-mm@kvack.org>,
	LKML <linux-kernel@vger.kernel.org>, Baoquan He <bhe@redhat.com>,
	Lorenzo Stoakes <lstoakes@gmail.com>,
	Christoph Hellwig <hch@infradead.org>,
	Matthew Wilcox <willy@infradead.org>,
	"Liam R . Howlett" <Liam.Howlett@oracle.com>,
	Dave Chinner <david@fromorbit.com>,
	"Paul E . McKenney" <paulmck@kernel.org>,
	Joel Fernandes <joel@joelfernandes.org>,
	Uladzislau Rezki <urezki@gmail.com>,
	Oleksiy Avramchenko <oleksiy.avramchenko@sony.com>
Subject: Re: [PATCH v2 4/9] mm: vmalloc: Remove global vmap_area_root rb-tree
Date: Tue, 29 Aug 2023 22:30:19 +0800	[thread overview]
Message-ID: <202308292228.RRrGUYyB-lkp@intel.com> (raw)
In-Reply-To: <20230829081142.3619-5-urezki@gmail.com>

Hi Uladzislau,

kernel test robot noticed the following build warnings:

[auto build test WARNING on akpm-mm/mm-everything]
[also build test WARNING on linus/master v6.5]
[If your patch is applied to the wrong git tree, kindly drop us a note.
And when submitting patch, we suggest to use '--base' as documented in
https://git-scm.com/docs/git-format-patch#_base_tree_information]

url:    https://github.com/intel-lab-lkp/linux/commits/Uladzislau-Rezki-Sony/mm-vmalloc-Add-va_alloc-helper/20230829-161248
base:   https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link:    https://lore.kernel.org/r/20230829081142.3619-5-urezki%40gmail.com
patch subject: [PATCH v2 4/9] mm: vmalloc: Remove global vmap_area_root rb-tree
config: csky-randconfig-r024-20230829 (https://download.01.org/0day-ci/archive/20230829/202308292228.RRrGUYyB-lkp@intel.com/config)
compiler: csky-linux-gcc (GCC) 13.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20230829/202308292228.RRrGUYyB-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/202308292228.RRrGUYyB-lkp@intel.com/

All warnings (new ones prefixed by >>):

   mm/vmalloc.c: In function 'vmap_init_free_space':
>> mm/vmalloc.c:4506:45: warning: ordered comparison of pointer with integer zero [-Wextra]
    4506 |                 if (busy->addr - vmap_start > 0) {
         |                                             ^

vim +4506 mm/vmalloc.c

  4491	
  4492	static void vmap_init_free_space(void)
  4493	{
  4494		unsigned long vmap_start = 1;
  4495		const unsigned long vmap_end = ULONG_MAX;
  4496		struct vmap_area *free;
  4497		struct vm_struct *busy;
  4498	
  4499		/*
  4500		 *     B     F     B     B     B     F
  4501		 * -|-----|.....|-----|-----|-----|.....|-
  4502		 *  |           The KVA space           |
  4503		 *  |<--------------------------------->|
  4504		 */
  4505		for (busy = vmlist; busy; busy = busy->next) {
> 4506			if (busy->addr - vmap_start > 0) {
  4507				free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
  4508				if (!WARN_ON_ONCE(!free)) {
  4509					free->va_start = vmap_start;
  4510					free->va_end = (unsigned long) busy->addr;
  4511	
  4512					insert_vmap_area_augment(free, NULL,
  4513						&free_vmap_area_root,
  4514							&free_vmap_area_list);
  4515				}
  4516			}
  4517	
  4518			vmap_start = (unsigned long) busy->addr + busy->size;
  4519		}
  4520	
  4521		if (vmap_end - vmap_start > 0) {
  4522			free = kmem_cache_zalloc(vmap_area_cachep, GFP_NOWAIT);
  4523			if (!WARN_ON_ONCE(!free)) {
  4524				free->va_start = vmap_start;
  4525				free->va_end = vmap_end;
  4526	
  4527				insert_vmap_area_augment(free, NULL,
  4528					&free_vmap_area_root,
  4529						&free_vmap_area_list);
  4530			}
  4531		}
  4532	}
  4533	

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