Re: [PATCH] mm: Fix shmem THP counters on migration
From: kernel test robot
Date: Mon Jun 19 2023 - 04:11:29 EST
Hi Jan,
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/Jan-Glauber/mm-Fix-shmem-THP-counters-on-migration/20230619-135947
base: https://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm.git mm-everything
patch link: https://lore.kernel.org/r/20230619055735.141740-1-jglauber%40digitalocean.com
patch subject: [PATCH] mm: Fix shmem THP counters on migration
config: sparc-randconfig-r024-20230619 (https://download.01.org/0day-ci/archive/20230619/202306191545.gATleHf1-lkp@xxxxxxxxx/config)
compiler: sparc-linux-gcc (GCC) 12.3.0
reproduce: (https://download.01.org/0day-ci/archive/20230619/202306191545.gATleHf1-lkp@xxxxxxxxx/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@xxxxxxxxx>
| Closes: https://lore.kernel.org/oe-kbuild-all/202306191545.gATleHf1-lkp@xxxxxxxxx/
All errors (new ones prefixed by >>):
mm/migrate.c: In function 'folio_migrate_mapping':
>> mm/migrate.c:491:64: error: 'NR_SHMEM_THP' undeclared (first use in this function); did you mean 'NR_SHMEM_THPS'?
491 | __mod_lruvec_state(old_lruvec, NR_SHMEM_THP, -nr);
| ^~~~~~~~~~~~
| NR_SHMEM_THPS
mm/migrate.c:491:64: note: each undeclared identifier is reported only once for each function it appears in
vim +491 mm/migrate.c
389
390 /*
391 * Replace the page in the mapping.
392 *
393 * The number of remaining references must be:
394 * 1 for anonymous pages without a mapping
395 * 2 for pages with a mapping
396 * 3 for pages with a mapping and PagePrivate/PagePrivate2 set.
397 */
398 int folio_migrate_mapping(struct address_space *mapping,
399 struct folio *newfolio, struct folio *folio, int extra_count)
400 {
401 XA_STATE(xas, &mapping->i_pages, folio_index(folio));
402 struct zone *oldzone, *newzone;
403 int dirty;
404 int expected_count = folio_expected_refs(mapping, folio) + extra_count;
405 long nr = folio_nr_pages(folio);
406
407 if (!mapping) {
408 /* Anonymous page without mapping */
409 if (folio_ref_count(folio) != expected_count)
410 return -EAGAIN;
411
412 /* No turning back from here */
413 newfolio->index = folio->index;
414 newfolio->mapping = folio->mapping;
415 if (folio_test_swapbacked(folio))
416 __folio_set_swapbacked(newfolio);
417
418 return MIGRATEPAGE_SUCCESS;
419 }
420
421 oldzone = folio_zone(folio);
422 newzone = folio_zone(newfolio);
423
424 xas_lock_irq(&xas);
425 if (!folio_ref_freeze(folio, expected_count)) {
426 xas_unlock_irq(&xas);
427 return -EAGAIN;
428 }
429
430 /*
431 * Now we know that no one else is looking at the folio:
432 * no turning back from here.
433 */
434 newfolio->index = folio->index;
435 newfolio->mapping = folio->mapping;
436 folio_ref_add(newfolio, nr); /* add cache reference */
437 if (folio_test_swapbacked(folio)) {
438 __folio_set_swapbacked(newfolio);
439 if (folio_test_swapcache(folio)) {
440 folio_set_swapcache(newfolio);
441 newfolio->private = folio_get_private(folio);
442 }
443 } else {
444 VM_BUG_ON_FOLIO(folio_test_swapcache(folio), folio);
445 }
446
447 /* Move dirty while page refs frozen and newpage not yet exposed */
448 dirty = folio_test_dirty(folio);
449 if (dirty) {
450 folio_clear_dirty(folio);
451 folio_set_dirty(newfolio);
452 }
453
454 xas_store(&xas, newfolio);
455
456 /*
457 * Drop cache reference from old page by unfreezing
458 * to one less reference.
459 * We know this isn't the last reference.
460 */
461 folio_ref_unfreeze(folio, expected_count - nr);
462
463 xas_unlock(&xas);
464 /* Leave irq disabled to prevent preemption while updating stats */
465
466 /*
467 * If moved to a different zone then also account
468 * the page for that zone. Other VM counters will be
469 * taken care of when we establish references to the
470 * new page and drop references to the old page.
471 *
472 * Note that anonymous pages are accounted for
473 * via NR_FILE_PAGES and NR_ANON_MAPPED if they
474 * are mapped to swap space.
475 */
476 if (newzone != oldzone) {
477 struct lruvec *old_lruvec, *new_lruvec;
478 struct mem_cgroup *memcg;
479
480 memcg = folio_memcg(folio);
481 old_lruvec = mem_cgroup_lruvec(memcg, oldzone->zone_pgdat);
482 new_lruvec = mem_cgroup_lruvec(memcg, newzone->zone_pgdat);
483
484 __mod_lruvec_state(old_lruvec, NR_FILE_PAGES, -nr);
485 __mod_lruvec_state(new_lruvec, NR_FILE_PAGES, nr);
486 if (folio_test_swapbacked(folio) && !folio_test_swapcache(folio)) {
487 __mod_lruvec_state(old_lruvec, NR_SHMEM, -nr);
488 __mod_lruvec_state(new_lruvec, NR_SHMEM, nr);
489
490 if (folio_test_transhuge(folio)) {
> 491 __mod_lruvec_state(old_lruvec, NR_SHMEM_THP, -nr);
492 __mod_lruvec_state(new_lruvec, NR_SHMEM_THP, nr);
493 }
494 }
495 #ifdef CONFIG_SWAP
496 if (folio_test_swapcache(folio)) {
497 __mod_lruvec_state(old_lruvec, NR_SWAPCACHE, -nr);
498 __mod_lruvec_state(new_lruvec, NR_SWAPCACHE, nr);
499 }
500 #endif
501 if (dirty && mapping_can_writeback(mapping)) {
502 __mod_lruvec_state(old_lruvec, NR_FILE_DIRTY, -nr);
503 __mod_zone_page_state(oldzone, NR_ZONE_WRITE_PENDING, -nr);
504 __mod_lruvec_state(new_lruvec, NR_FILE_DIRTY, nr);
505 __mod_zone_page_state(newzone, NR_ZONE_WRITE_PENDING, nr);
506 }
507 }
508 local_irq_enable();
509
510 return MIGRATEPAGE_SUCCESS;
511 }
512 EXPORT_SYMBOL(folio_migrate_mapping);
513
--
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https://github.com/intel/lkp-tests/wiki