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 464B14192EC; Tue, 30 Jun 2026 14:17:40 +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=1782829061; cv=none; b=SdB3C/7BsyvqGWfnUnFc/2N4V9OZLrRkNLVcHHuW+Cn7NqH3A1/gLrd8M6beE86rNWMV/K9cuqWCcY5mx6xvZ5at2Hd2mwH2lPbCs0ns76pw4YxdH6sR7JNIVmeEcAwyj53/hu+rCDzNdj8Vl9zC38AQ8pka/DoxGpFHYAPVsvE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1782829061; c=relaxed/simple; bh=oNcYmQpMlLqn/8NYE11BqPV6jYmgrD3VqsyPJhcMnwo=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version; b=i9H/nobllDtgx4rvNK9/3Mqu6gYPIaYHdfeAS4hVMLClTmzYAIc9GDGAhth1emEDKU63L4ptrd4fcEGyx2BcjCOVbtFCm/GDdgOTLIio/iqGetBSNLN+GqHjTW9Zk0JqO8wC4bovKU5NStqFo+fV93lJYQ+tcyeVTQN9YH+EqvY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=U6y75598; 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="U6y75598" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 1E3371F00A3A; Tue, 30 Jun 2026 14:17:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1782829060; bh=2uS6dozko2yZPUVNoFA79ufpLiFmvL+C2qUOX4NrXFs=; h=From:To:Cc:Subject:Date:In-Reply-To:References; b=U6y75598emWFv7MuquKR3xnTvI5bWm5OwWmd1cKX6WS/8PTsllnL5LZuUhTEMgKal O0yGoQwcKRjp8V1+meDk3bf4ht4oiCY1RJ0guY4NEMcS3jef1Fp+OVmEkPK9Xnx4UP uGIKOrc8oPLh5dSgKHdo50VgaNwRymnp28/Ai9Pilo/xnj/e4bwyekzTUNr/eNqpUz V/cN044WEmjwN+9s6lAGYBlTOj8iMSStzNTUp10tqWvYyJ+GsSKs5LNg/F+0gdsdlA 2J6deVAtXsXkmpanniBCqVvNr00O6TAoqVvTfZQGCm/w/wWNwUA3mjFxNVbNvLLRc9 PBrUw8XoMYqLQ== From: SJ Park To: Andrew Morton Cc: SJ Park , 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: [PATCH 03/11] mm/damon/tests/core-kunit: test damon_rand() Date: Tue, 30 Jun 2026 07:17:17 -0700 Message-ID: <20260630141726.92246-4-sj@kernel.org> X-Mailer: git-send-email 2.47.3 In-Reply-To: <20260630141726.92246-1-sj@kernel.org> References: <20260630141726.92246-1-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: SJ 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 aef7e0553cba4..0124f83b39b83 100644 --- a/mm/damon/tests/core-kunit.h +++ b/mm/damon/tests/core-kunit.h @@ -1547,6 +1547,20 @@ static void damon_test_walk_control_obsolete(struct kunit *test) damon_destroy_ctx(ctx); } +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), @@ -1578,6 +1592,7 @@ static struct kunit_case damon_test_cases[] = { KUNIT_CASE(damon_test_apply_min_nr_regions), KUNIT_CASE(damon_test_is_last_region), KUNIT_CASE(damon_test_walk_control_obsolete), + KUNIT_CASE(damon_test_rand), {}, }; -- 2.47.3