[bug report] drm/xe: Add a xe_bo subtest for shrinking / swapping
Dan Carpenter
dan.carpenter at linaro.org
Fri Sep 13 08:34:49 UTC 2024
Hello Thomas Hellström,
Commit 5a90b60db5e6 ("drm/xe: Add a xe_bo subtest for shrinking /
swapping") from Sep 9, 2024 (linux-next), leads to the following
Smatch static checker warning:
drivers/gpu/drm/xe/tests/xe_bo.c:472 shrink_test_run_device()
error: uninitialized symbol 'purgeable'.
drivers/gpu/drm/xe/tests/xe_bo.c
437 static int shrink_test_run_device(struct xe_device *xe)
438 {
439 struct kunit *test = kunit_get_current_test();
440 LIST_HEAD(bos);
441 struct xe_bo_link *link, *next;
442 struct sysinfo si;
443 size_t ram, ram_and_swap, purgeable, alloced, to_alloc, limit;
444 unsigned int interrupted = 0, successful = 0, count = 0;
445 struct rnd_state prng;
446 u64 rand_seed;
447 bool failed = false;
448
449 rand_seed = get_random_u64();
450 prandom_seed_state(&prng, rand_seed);
451 kunit_info(test, "Random seed is 0x%016llx.\n",
452 (unsigned long long)rand_seed);
453
454 /* Skip if execution time is expected to be too long. */
455
456 limit = SZ_32G;
457 /* IGFX with flat CCS needs to copy when swapping / shrinking */
458 if (!IS_DGFX(xe) && xe_device_has_flat_ccs(xe))
459 limit = SZ_16G;
460
461 si_meminfo(&si);
462 ram = (size_t)si.freeram * si.mem_unit;
463 if (ram > limit) {
464 kunit_skip(test, "Too long expected execution time.\n");
465 return 0;
466 }
467 to_alloc = ram * 2;
468
469 ram_and_swap = ram + get_nr_swap_pages() * PAGE_SIZE;
470 if (to_alloc > ram_and_swap)
471 purgeable = to_alloc - ram_and_swap;
purgeable isn't initialized on the else path. Also I think Sparse will complain
that there is another bool purgeable variable declared later in the function so
the name is potentially confusing.
regards,
dan carpenter
--> 472 purgeable += purgeable / 5;
473
474 kunit_info(test, "Free ram is %lu bytes. Will allocate twice of that.\n",
475 (unsigned long)ram);
476 for (alloced = 0; alloced < to_alloc; alloced += XE_BO_SHRINK_SIZE) {
477 struct xe_bo *bo;
478 unsigned int mem_type;
479 struct xe_ttm_tt *xe_tt;
480
481 link = kzalloc(sizeof(*link), GFP_KERNEL);
482 if (!link) {
483 KUNIT_FAIL(test, "Unexpected link allocation failure\n");
484 failed = true;
485 break;
486 }
487
488 INIT_LIST_HEAD(&link->link);
489
490 /* We can create bos using WC caching here. But it is slower. */
491 bo = xe_bo_create_user(xe, NULL, NULL, XE_BO_SHRINK_SIZE,
492 DRM_XE_GEM_CPU_CACHING_WB,
493 XE_BO_FLAG_SYSTEM);
494 if (IS_ERR(bo)) {
495 if (bo != ERR_PTR(-ENOMEM) && bo != ERR_PTR(-ENOSPC) &&
496 bo != ERR_PTR(-EINTR) && bo != ERR_PTR(-ERESTARTSYS))
497 KUNIT_FAIL(test, "Error creating bo: %pe\n", bo);
498 kfree(link);
499 failed = true;
500 break;
501 }
502 xe_bo_lock(bo, false);
503 xe_tt = container_of(bo->ttm.ttm, typeof(*xe_tt), ttm);
504
505 /*
506 * Allocate purgeable bos first, because if we do it the
507 * other way around, they may not be subject to swapping...
508 */
509 if (alloced < purgeable) {
510 xe_tt->purgeable = true;
511 bo->ttm.priority = 0;
512 } else {
513 int ret = shrink_test_fill_random(bo, &prng, link);
514
515 if (ret) {
516 xe_bo_unlock(bo);
517 xe_bo_put(bo);
518 KUNIT_FAIL(test, "Error filling bo with random data: %pe\n",
519 ERR_PTR(ret));
520 kfree(link);
521 failed = true;
522 break;
523 }
524 }
525
526 mem_type = bo->ttm.resource->mem_type;
527 xe_bo_unlock(bo);
528 link->bo = bo;
529 list_add_tail(&link->link, &bos);
530
531 if (mem_type != XE_PL_TT) {
532 KUNIT_FAIL(test, "Bo in incorrect memory type: %u\n",
533 bo->ttm.resource->mem_type);
534 failed = true;
535 }
536 cond_resched();
537 if (signal_pending(current))
538 break;
539 }
540
541 /*
542 * Read back and destroy bos. Reset the pseudo-random seed to get an
543 * identical pseudo-random number sequence for readback.
544 */
545 prandom_seed_state(&prng, rand_seed);
546 list_for_each_entry_safe(link, next, &bos, link) {
547 static struct ttm_operation_ctx ctx = {.interruptible = true};
548 struct xe_bo *bo = link->bo;
549 struct xe_ttm_tt *xe_tt;
550 int ret;
551
552 count++;
553 if (!signal_pending(current) && !failed) {
554 bool purgeable, intr = false;
555
556 xe_bo_lock(bo, NULL);
557
558 /* xe_tt->purgeable is cleared on validate. */
559 xe_tt = container_of(bo->ttm.ttm, typeof(*xe_tt), ttm);
560 purgeable = xe_tt->purgeable;
561 do {
562 ret = ttm_bo_validate(&bo->ttm, &tt_placement, &ctx);
563 if (ret == -EINTR)
564 intr = true;
565 } while (ret == -EINTR && !signal_pending(current));
566
567 if (!ret && !purgeable)
568 failed = shrink_test_verify(test, bo, count, &prng, link);
569
570 xe_bo_unlock(bo);
571 if (ret) {
572 KUNIT_FAIL(test, "Validation failed: %pe\n",
573 ERR_PTR(ret));
574 failed = true;
575 } else if (intr) {
576 interrupted++;
577 } else {
578 successful++;
579 }
580 }
581 xe_bo_put(link->bo);
582 list_del(&link->link);
583 kfree(link);
584 }
585 kunit_info(test, "Readbacks interrupted: %u successful: %u\n",
586 interrupted, successful);
587
588 return 0;
589 }
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