On 21-10-2026 22:54, [email protected] wrote:
Thank you for your contribution! Sashiko AI review found 1 potential issue(s)
to consider:
- [Low] gpu/tests/buddy: 64-bit division in gpu_test_buddy_range_bias_pruning()
--
commit c218b91af95d861d31913d5c9b3ba0681e319523
Author: Sanjay Yadav <[email protected]>
gpu/tests/buddy: Add range-bias pruning and free-order tracking tests
This commit adds KUnit tests in drivers/gpu/tests/gpu_buddy_test.c to verify
range-bias subtree pruning and subtree_max_free_order tracking across block
allocation, splitting, coalescing, and trimming operations.
diff --git a/drivers/gpu/tests/gpu_buddy_test.c
b/drivers/gpu/tests/gpu_buddy_test.c
index b75d32ca6ca0a..4c7e823d57892 100644
--- a/drivers/gpu/tests/gpu_buddy_test.c
+++ b/drivers/gpu/tests/gpu_buddy_test.c
@@ -1586,6 +1586,311 @@ static void gpu_test_buddy_addr_to_block(struct kunit
*test)
gpu_buddy_fini(&mm);
}
[ ... ]
+static void gpu_test_buddy_range_bias_pruning(struct kunit *test)
+{
+ const u64 mm_size = SZ_512M, range_end = SZ_128M, chunk = SZ_4K;
+ const unsigned int nr = range_end / chunk, window = 1024;
+ const u64 holes[] = { 0, range_end / 2 + 3 * chunk };
+ struct gpu_buddy_block *block, *hidden;
+ u64 first_ns = 0, last_ns = 0;
+ unsigned int i, misplaced = 0;
+ LIST_HEAD(allocated);
+ struct gpu_buddy mm;
+ LIST_HEAD(tmp);
+ int err;
[ ... ]
+ for (i = 0; i < nr; i++) {
+ ktime_t start = ktime_get();
+ u64 elapsed;
+
+ err = gpu_buddy_alloc_blocks(&mm, 0, range_end, chunk, chunk,
+ &allocated,
GPU_BUDDY_RANGE_ALLOCATION);
+ elapsed = ktime_to_ns(ktime_sub(ktime_get(), start));
+ KUNIT_ASSERT_EQ_MSG(test, err, 0, "range alloc %u failed\n", i);
+
+ if (i < window)
+ first_ns += elapsed;
+ else if (i >= nr - window)
+ last_ns += elapsed;
+
+ block = list_last_entry(&allocated, struct gpu_buddy_block,
link);
+ if (gpu_buddy_block_offset(block) != range_end - (u64)(i + 1) *
chunk)
+ misplaced++;
+ }
+
+ kunit_info(test, "first %u range allocs: %llu us, last %u: %llu us\n",
+ window, first_ns / NSEC_PER_USEC, window, last_ns /
NSEC_PER_USEC);
[Severity: Low]
In gpu_test_buddy_range_bias_pruning() in drivers/gpu/tests/gpu_buddy_test.c,
first_ns and last_ns are u64 variables that accumulate runtime nanosecond
durations. On 32-bit architectures with CONFIG_GPU_BUDDY_KUNIT_TEST enabled,
won't dividing them directly with the / operator by NSEC_PER_USEC emit calls
to __udivdi3 or __aeabi_uldivmod and cause a link failure?
Should this use div_u64() (or ktime_to_us()) instead?
Yes, this matches the kernel test robot’s __aeabi_uldivmod failure on
32-bit ARM.
I reproduced it locally on 32bit compiler and confirmed that replacing
the direct u64 divisions with div_u64() fixes the issue.
[ ... ]
