Re: [PATCH] mm: skip CMA pages when they are not available
From: kernel test robot
Date: Wed Apr 19 2023 - 07:37:02 EST
Hi zhaoyang.huang,
kernel test robot noticed the following build errors:
[auto build test ERROR on akpm-mm/mm-everything]
url: https://github.com/intel-lab-lkp/linux/commits/zhaoyang-huang/mm-skip-CMA-pages-when-they-are-not-available/20230419-134421
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/1681882824-17532-1-git-send-email-zhaoyang.huang%40unisoc.com
patch subject: [PATCH] mm: skip CMA pages when they are not available
config: i386-randconfig-a012-20230417 (https://download.01.org/0day-ci/archive/20230419/202304191908.Bqx6phWT-lkp@xxxxxxxxx/config)
compiler: clang version 14.0.6 (https://github.com/llvm/llvm-project f28c006a5895fc0e329fe15fead81e37457cb1d1)
reproduce (this is a W=1 build):
wget https://raw.githubusercontent.com/intel/lkp-tests/master/sbin/make.cross -O ~/bin/make.cross
chmod +x ~/bin/make.cross
# https://github.com/intel-lab-lkp/linux/commit/346b74f2bf2155cb8be6af66b346157c7681b9c9
git remote add linux-review https://github.com/intel-lab-lkp/linux
git fetch --no-tags linux-review zhaoyang-huang/mm-skip-CMA-pages-when-they-are-not-available/20230419-134421
git checkout 346b74f2bf2155cb8be6af66b346157c7681b9c9
# save the config file
mkdir build_dir && cp config build_dir/.config
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 olddefconfig
COMPILER_INSTALL_PATH=$HOME/0day COMPILER=clang make.cross W=1 O=build_dir ARCH=i386 SHELL=/bin/bash
If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp@xxxxxxxxx>
| Link: https://lore.kernel.org/oe-kbuild-all/202304191908.Bqx6phWT-lkp@xxxxxxxxx/
All errors (new ones prefixed by >>):
>> mm/vmscan.c:2317:40: error: use of undeclared identifier 'MIGRATE_CMA'; did you mean 'MIGRATE_SYNC'?
(get_pageblock_migratetype(page) == MIGRATE_CMA && !cma_cap)) {
^~~~~~~~~~~
MIGRATE_SYNC
include/linux/migrate_mode.h:18:2: note: 'MIGRATE_SYNC' declared here
MIGRATE_SYNC,
^
1 error generated.
vim +2317 mm/vmscan.c
2261
2262 /*
2263 * Isolating page from the lruvec to fill in @dst list by nr_to_scan times.
2264 *
2265 * lruvec->lru_lock is heavily contended. Some of the functions that
2266 * shrink the lists perform better by taking out a batch of pages
2267 * and working on them outside the LRU lock.
2268 *
2269 * For pagecache intensive workloads, this function is the hottest
2270 * spot in the kernel (apart from copy_*_user functions).
2271 *
2272 * Lru_lock must be held before calling this function.
2273 *
2274 * @nr_to_scan: The number of eligible pages to look through on the list.
2275 * @lruvec: The LRU vector to pull pages from.
2276 * @dst: The temp list to put pages on to.
2277 * @nr_scanned: The number of pages that were scanned.
2278 * @sc: The scan_control struct for this reclaim session
2279 * @lru: LRU list id for isolating
2280 *
2281 * returns how many pages were moved onto *@dst.
2282 */
2283 static unsigned long isolate_lru_folios(unsigned long nr_to_scan,
2284 struct lruvec *lruvec, struct list_head *dst,
2285 unsigned long *nr_scanned, struct scan_control *sc,
2286 enum lru_list lru)
2287 {
2288 struct list_head *src = &lruvec->lists[lru];
2289 unsigned long nr_taken = 0;
2290 unsigned long nr_zone_taken[MAX_NR_ZONES] = { 0 };
2291 unsigned long nr_skipped[MAX_NR_ZONES] = { 0, };
2292 unsigned long skipped = 0;
2293 unsigned long scan, total_scan, nr_pages;
2294 bool cma_cap = true;
2295 struct page *page;
2296 LIST_HEAD(folios_skipped);
2297
2298 total_scan = 0;
2299 scan = 0;
2300 if ((IS_ENABLED(CONFIG_CMA)) && !current_is_kswapd()
2301 && (gfp_migratetype(sc->gfp_mask) != MIGRATE_MOVABLE))
2302 cma_cap = false;
2303
2304 while (scan < nr_to_scan && !list_empty(src)) {
2305 struct list_head *move_to = src;
2306 struct folio *folio;
2307
2308 folio = lru_to_folio(src);
2309 prefetchw_prev_lru_folio(folio, src, flags);
2310
2311 nr_pages = folio_nr_pages(folio);
2312 total_scan += nr_pages;
2313
2314 page = &folio->page;
2315
2316 if (folio_zonenum(folio) > sc->reclaim_idx ||
> 2317 (get_pageblock_migratetype(page) == MIGRATE_CMA && !cma_cap)) {
2318 nr_skipped[folio_zonenum(folio)] += nr_pages;
2319 move_to = &folios_skipped;
2320 goto move;
2321 }
2322
2323 /*
2324 * Do not count skipped folios because that makes the function
2325 * return with no isolated folios if the LRU mostly contains
2326 * ineligible folios. This causes the VM to not reclaim any
2327 * folios, triggering a premature OOM.
2328 * Account all pages in a folio.
2329 */
2330 scan += nr_pages;
2331
2332 if (!folio_test_lru(folio))
2333 goto move;
2334 if (!sc->may_unmap && folio_mapped(folio))
2335 goto move;
2336
2337 /*
2338 * Be careful not to clear the lru flag until after we're
2339 * sure the folio is not being freed elsewhere -- the
2340 * folio release code relies on it.
2341 */
2342 if (unlikely(!folio_try_get(folio)))
2343 goto move;
2344
2345 if (!folio_test_clear_lru(folio)) {
2346 /* Another thread is already isolating this folio */
2347 folio_put(folio);
2348 goto move;
2349 }
2350
2351 nr_taken += nr_pages;
2352 nr_zone_taken[folio_zonenum(folio)] += nr_pages;
2353 move_to = dst;
2354 move:
2355 list_move(&folio->lru, move_to);
2356 }
2357
2358 /*
2359 * Splice any skipped folios to the start of the LRU list. Note that
2360 * this disrupts the LRU order when reclaiming for lower zones but
2361 * we cannot splice to the tail. If we did then the SWAP_CLUSTER_MAX
2362 * scanning would soon rescan the same folios to skip and waste lots
2363 * of cpu cycles.
2364 */
2365 if (!list_empty(&folios_skipped)) {
2366 int zid;
2367
2368 list_splice(&folios_skipped, src);
2369 for (zid = 0; zid < MAX_NR_ZONES; zid++) {
2370 if (!nr_skipped[zid])
2371 continue;
2372
2373 __count_zid_vm_events(PGSCAN_SKIP, zid, nr_skipped[zid]);
2374 skipped += nr_skipped[zid];
2375 }
2376 }
2377 *nr_scanned = total_scan;
2378 trace_mm_vmscan_lru_isolate(sc->reclaim_idx, sc->order, nr_to_scan,
2379 total_scan, skipped, nr_taken,
2380 sc->may_unmap ? 0 : ISOLATE_UNMAPPED, lru);
2381 update_lru_sizes(lruvec, lru, nr_zone_taken);
2382 return nr_taken;
2383 }
2384
--
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests