From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 99A303644A2; Thu, 25 Jun 2026 14:24:42 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782397483; cv=none; b=KqgAm/uRYu6ySJexOHzAeIEG0dtdpL4CTLCTLvPHTkB+JKvjeupCjRfPq7ETMWrueTp2Yz0o2z2wOJHmJm7728xXIyJMqyqxQYuFNsDX5dx82Biut/uoDRexdGTEpejO4CdpvGMnAKo5LIsVlil9zIDmAIJulWgBzI+5DPKy1PU= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782397483; c=relaxed/simple; bh=23dDG2LxMLdWthQFd/idibL4PqE/amPFLAPjiZeibZ4=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=rhw8RIjkobjO9C2SjatMutepjK3Av0Xkq0ZHEIhD6P5u8HoOlevcAtP3Ic+Jud9F+L35BQlEl5WmqVxxamxML8u0fO9V9+MEVWhHYv6oCS8P8jRBNn+6TBlTusv6tiy3PO3EcC+d8SO+bSloo9fDfdmR0LNAnjlHmbu7F4Gm/Ts= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=nmhtcTjn; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="nmhtcTjn" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 32AE61F00A3F; Thu, 25 Jun 2026 14:24:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782397482; bh=Tg2jmDMliQWq/p4UiCF6FYRtQk7AyMDI0guNB97ZZdQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=nmhtcTjntOUk+GVd/GfKi40OpFXwJThGcv2dCmao/FoMUpdHYTbjgQuae+KDJgvsA 77ud0y9bYni6U61DzFx18SC7GA8e/ky8Oh5UxIKc3BxAIkCmrJNm7dlubHHrhngVih s9IlZ3GcPv765b5zQTMU9rWRamkTWFsc5/RE+EmiVfRhJoT44W+10eqhIPw8z4AQLa GKyHDB8CgjWrlLnto5JKzpONAw/WOI+v2SZ7oCa2pXEIVjStFMS644HFtrQzUVCtZk DVMRxlQ9DRh79hiqK4sA4/R9D/dMBiBjgNJhiY556tKOw8JZYjIKyTQDmtc82fCdKd luiK0uUG7Rgyw== From: SeongJae Park To: Cc: SeongJae Park , Andrew Morton , Brendan Higgins , David Gow , damon@lists.linux.dev, kunit-dev@googlegroups.com, linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, linux-mm@kvack.org Subject: [RFC PATCH v1.2 03/11] mm/damon/tests/core-kunit: test damon_rand() Date: Thu, 25 Jun 2026 07:23:48 -0700 Message-ID: <20260625142357.103500-4-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260625142357.103500-1-sj@kernel.org> References: <20260625142357.103500-1-sj@kernel.org> Precedence: bulk X-Mailing-List: damon@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Commit 9012c4e647df ("mm/damon: replace damon_rand() with a per-ctx lockless PRNG") optimized DAMON for better performance. Add a kunit test for ensuring the bounds of the output. Signed-off-by: SeongJae Park --- mm/damon/tests/core-kunit.h | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h index 1cfb8c176b873..eec7cb325a431 100644 --- a/mm/damon/tests/core-kunit.h +++ b/mm/damon/tests/core-kunit.h @@ -1460,6 +1460,22 @@ static void damon_test_is_last_region(struct kunit *test) damon_free_target(t); } +static void damon_test_rand(struct kunit *test) +{ + struct damon_ctx ctx; + int counts[10] = {}; + int i; + + prandom_seed_state(&ctx.rnd_state, get_random_u64()); + for (i = 0; i < 10000; i++) { + unsigned long rnd = damon_rand(&ctx, 0, 10); + + KUNIT_EXPECT_GE(test, rnd, 0); + KUNIT_EXPECT_LE(test, rnd, 9); + counts[rnd]++; + } +} + static struct kunit_case damon_test_cases[] = { KUNIT_CASE(damon_test_target), KUNIT_CASE(damon_test_regions), @@ -1489,6 +1505,7 @@ static struct kunit_case damon_test_cases[] = { KUNIT_CASE(damon_test_set_filters_default_reject), KUNIT_CASE(damon_test_apply_min_nr_regions), KUNIT_CASE(damon_test_is_last_region), + KUNIT_CASE(damon_test_rand), {}, }; -- 2.47.3