Re: [PATCH 1/2] mm/zswap: global lru and shrinker shared by all zswap_pools

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

Hi Chengming,

kernel test robot noticed the following build errors:

[auto build test ERROR on 191d97734e41a5c9f90a2f6636fdd335ae1d435d]

url:    https://github.com/intel-lab-lkp/linux/commits/Chengming-Zhou/mm-zswap-global-lru-and-shrinker-shared-by-all-zswap_pools/20240211-220028
base:   191d97734e41a5c9f90a2f6636fdd335ae1d435d
patch link:    https://lore.kernel.org/r/20240210-zswap-global-lru-v1-1-853473d7b0da%40bytedance.com
patch subject: [PATCH 1/2] mm/zswap: global lru and shrinker shared by all zswap_pools
config: x86_64-randconfig-013-20240211 (https://download.01.org/0day-ci/archive/20240212/202402120226.TK7G37U9-lkp@intel.com/config)
compiler: gcc-12 (Debian 12.2.0-14) 12.2.0
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240212/202402120226.TK7G37U9-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/202402120226.TK7G37U9-lkp@intel.com/

All errors (new ones prefixed by >>):

   mm/zswap.c: In function 'zswap_shrinker_count':
>> mm/zswap.c:1300:42: error: 'pool' undeclared (first use in this function); did you mean 'zpool'?
    1300 |         nr_backing = get_zswap_pool_size(pool) >> PAGE_SHIFT;
         |                                          ^~~~
         |                                          zpool
   mm/zswap.c:1300:42: note: each undeclared identifier is reported only once for each function it appears in

Kconfig warnings: (for reference only)
   WARNING: unmet direct dependencies detected for DRM_I915_DEBUG_GEM
   Depends on [n]: HAS_IOMEM [=y] && DRM_I915 [=y] && EXPERT [=y] && DRM_I915_WERROR [=n]
   Selected by [y]:
   - DRM_I915_DEBUG [=y] && HAS_IOMEM [=y] && DRM_I915 [=y] && EXPERT [=y] && !COMPILE_TEST [=n]


vim +1300 mm/zswap.c

b5ba474f3f5187 Nhat Pham      2023-11-30  1283  
b5ba474f3f5187 Nhat Pham      2023-11-30  1284  static unsigned long zswap_shrinker_count(struct shrinker *shrinker,
b5ba474f3f5187 Nhat Pham      2023-11-30  1285  		struct shrink_control *sc)
b5ba474f3f5187 Nhat Pham      2023-11-30  1286  {
b5ba474f3f5187 Nhat Pham      2023-11-30  1287  	struct mem_cgroup *memcg = sc->memcg;
b5ba474f3f5187 Nhat Pham      2023-11-30  1288  	struct lruvec *lruvec = mem_cgroup_lruvec(memcg, NODE_DATA(sc->nid));
b5ba474f3f5187 Nhat Pham      2023-11-30  1289  	unsigned long nr_backing, nr_stored, nr_freeable, nr_protected;
b5ba474f3f5187 Nhat Pham      2023-11-30  1290  
501a06fe8e4c18 Nhat Pham      2023-12-07  1291  	if (!zswap_shrinker_enabled || !mem_cgroup_zswap_writeback_enabled(memcg))
b5ba474f3f5187 Nhat Pham      2023-11-30  1292  		return 0;
b5ba474f3f5187 Nhat Pham      2023-11-30  1293  
b5ba474f3f5187 Nhat Pham      2023-11-30  1294  #ifdef CONFIG_MEMCG_KMEM
7d7ef0a4686abe Yosry Ahmed    2023-11-29  1295  	mem_cgroup_flush_stats(memcg);
b5ba474f3f5187 Nhat Pham      2023-11-30  1296  	nr_backing = memcg_page_state(memcg, MEMCG_ZSWAP_B) >> PAGE_SHIFT;
b5ba474f3f5187 Nhat Pham      2023-11-30  1297  	nr_stored = memcg_page_state(memcg, MEMCG_ZSWAPPED);
b5ba474f3f5187 Nhat Pham      2023-11-30  1298  #else
b5ba474f3f5187 Nhat Pham      2023-11-30  1299  	/* use pool stats instead of memcg stats */
b5ba474f3f5187 Nhat Pham      2023-11-30 @1300  	nr_backing = get_zswap_pool_size(pool) >> PAGE_SHIFT;
bf414d6ae81ba2 Chengming Zhou 2024-02-11  1301  	nr_stored = atomic_read(&zswap.nr_stored);
b5ba474f3f5187 Nhat Pham      2023-11-30  1302  #endif
b5ba474f3f5187 Nhat Pham      2023-11-30  1303  
b5ba474f3f5187 Nhat Pham      2023-11-30  1304  	if (!nr_stored)
b5ba474f3f5187 Nhat Pham      2023-11-30  1305  		return 0;
b5ba474f3f5187 Nhat Pham      2023-11-30  1306  
b5ba474f3f5187 Nhat Pham      2023-11-30  1307  	nr_protected =
b5ba474f3f5187 Nhat Pham      2023-11-30  1308  		atomic_long_read(&lruvec->zswap_lruvec_state.nr_zswap_protected);
bf414d6ae81ba2 Chengming Zhou 2024-02-11  1309  	nr_freeable = list_lru_shrink_count(&zswap.list_lru, sc);
b5ba474f3f5187 Nhat Pham      2023-11-30  1310  	/*
b5ba474f3f5187 Nhat Pham      2023-11-30  1311  	 * Subtract the lru size by an estimate of the number of pages
b5ba474f3f5187 Nhat Pham      2023-11-30  1312  	 * that should be protected.
b5ba474f3f5187 Nhat Pham      2023-11-30  1313  	 */
b5ba474f3f5187 Nhat Pham      2023-11-30  1314  	nr_freeable = nr_freeable > nr_protected ? nr_freeable - nr_protected : 0;
b5ba474f3f5187 Nhat Pham      2023-11-30  1315  
b5ba474f3f5187 Nhat Pham      2023-11-30  1316  	/*
b5ba474f3f5187 Nhat Pham      2023-11-30  1317  	 * Scale the number of freeable pages by the memory saving factor.
b5ba474f3f5187 Nhat Pham      2023-11-30  1318  	 * This ensures that the better zswap compresses memory, the fewer
b5ba474f3f5187 Nhat Pham      2023-11-30  1319  	 * pages we will evict to swap (as it will otherwise incur IO for
b5ba474f3f5187 Nhat Pham      2023-11-30  1320  	 * relatively small memory saving).
b5ba474f3f5187 Nhat Pham      2023-11-30  1321  	 */
b5ba474f3f5187 Nhat Pham      2023-11-30  1322  	return mult_frac(nr_freeable, nr_backing, nr_stored);
b5ba474f3f5187 Nhat Pham      2023-11-30  1323  }
b5ba474f3f5187 Nhat Pham      2023-11-30  1324  

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