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 23E3F284B37; Fri, 26 Jun 2026 00:17:03 +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=1782433025; cv=none; b=iLfsmg7aiRIoMXtiQIHx37CDJSdCMXwiKdJisZYmi95jM3uom6rn3jSvb5njXq9+MC2vRuCwcqa3O6VGgnzvT6KLuI1kHK/6j5YrhpGTmjYW6uRkYcWbmdmgjChlI+JPWPWe3XPOlt6kjrXqlS7l7KVPBGumqEJ3e+5jBBxCeK0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782433025; c=relaxed/simple; bh=9AhhRDZ1bU+GUz5WFkYsc+ZGyO0zp6Dw3Zqto2My7Mg=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=YOmoKDq2HJRSnCJA+eqRBOuJi6XykRj6Ws+1b+Ratf0OnH+M8Is6yPljSgO5XghRmjx5i1vAicBCQ+96+vbuZYU7KybaXQaJEv9UfyssNrhAaBPC+G323lDrW7B0FIb5vfeLeYhmMoPUqMrzi6F9gTp8+TKH3wzPoIn5YCMichI= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=HJrhdGvj; 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="HJrhdGvj" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 500C41F00A3D; Fri, 26 Jun 2026 00:17:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782433023; bh=2dKSzklg/iygza9/Q9kj3LGtbFghgmmhxZCw/eIqgzY=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=HJrhdGvj3mMyAr45edesRy1s4UQtEBtCTDY+FxTtS3/BZvgzvKbVfPO5j7rbT2ttW 6RBc88u+FgIP9uty5oDQoJC1WMR4oyCLPqhS08snJ6mLTyVg67Bep2DImBhgT+7NXa Gaz0ER4ZTKIEfDsMa4ZgF+1+pbV57yMYo8ow8/bu0EsCHPUepKy37hwW+50u00Z6TX k3KsVyVtO1yVrZgh+91FXpEFG1uVYN5lVRgP4tz37xE3inWOeaKL27mERGckxogk9d xzG7e3wR3SErovAc2l/MKG0PXiyfUTPXTX3LEFV2PSJeTWO5/Gza9dl6YpQ2yjOZZV QG8npMF+HiDRg== 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 v1.3 03/11] mm/damon/tests/core-kunit: test damon_rand() Date: Thu, 25 Jun 2026 17:16:34 -0700 Message-ID: <20260626001644.85825-4-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260626001644.85825-1-sj@kernel.org> References: <20260626001644.85825-1-sj@kernel.org> Precedence: bulk X-Mailing-List: linux-kselftest@vger.kernel.org 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 | 15 +++++++++++++++ 1 file changed, 15 insertions(+) diff --git a/mm/damon/tests/core-kunit.h b/mm/damon/tests/core-kunit.h index 1cfb8c176b873..282670b0fa908 100644 --- a/mm/damon/tests/core-kunit.h +++ b/mm/damon/tests/core-kunit.h @@ -1460,6 +1460,20 @@ 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 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); + } +} + static struct kunit_case damon_test_cases[] = { KUNIT_CASE(damon_test_target), KUNIT_CASE(damon_test_regions), @@ -1489,6 +1503,7 @@ 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