From nobody Mon Apr 6 09:10:39 2026 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) (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 838442BDC0E for ; Sun, 22 Mar 2026 06:11:07 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=170.10.133.124 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774159869; cv=none; b=XMrXds/a6jxDe3LBDfZfrONHPO0vCuImlmBW1ZzKWYkpddIhvE0G7yeuhOXT7+j0ICgckNYUYVC16Ts44ZdCbC5s6V6NJQody+qy1uwjMK6dcF4En343jUKb/xD14+7QLiXwf3EAV0m/55EJ7/x9FPf8OiMYYEbVS7JMkNmqLpA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1774159869; c=relaxed/simple; bh=bTtTmHzOaXBPfSb93wDC7JBVrSsV7C9Odj5YuC8P8WU=; h=From:To:Cc:Subject:Date:Message-ID:In-Reply-To:References: MIME-Version:Content-Type; b=dOQa9xjdij0YAfkF6ul9lCq9/b1tAC6D+LkKGYtlqnTM87k+va7R+DHLgwxPFpZ5k8/c2Nw3daOw8gH2tQPfK1I64qGaT5DPN+MLq/xySIVb7wy0nIXEaYtXe6vwvb5NTPT36L+qwUTvIGgi0CNMOLrks4qiGqe/PeKyp/K8i6s= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com; spf=pass smtp.mailfrom=redhat.com; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b=VQyaVJMN; arc=none smtp.client-ip=170.10.133.124 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=quarantine dis=none) header.from=redhat.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=redhat.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=redhat.com header.i=@redhat.com header.b="VQyaVJMN" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1774159866; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=vNGT0NUnZrlZkAGbpAJMOumDHRLMeHSt0H7KNvOLnUM=; b=VQyaVJMN9xFMKDgUiazFH4qYr07gaMGAqvt78uVz2t4Ejdk8BNtkJqeI5NMCLl7pLNoYbM bF6FXb770xvqDech8cx9fKID4TtEDBe/AVtZ4uKe9NeEYz1DYOL/+uoULwzrPErk/ldEfP iwolj+zOAYz3CO6VkkNK7iHaq/+V7f4= Received: from mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (ec2-35-165-154-97.us-west-2.compute.amazonaws.com [35.165.154.97]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-190-FE9ADUPzNtOwM6-JUgdTbg-1; Sun, 22 Mar 2026 02:11:01 -0400 X-MC-Unique: FE9ADUPzNtOwM6-JUgdTbg-1 X-Mimecast-MFC-AGG-ID: FE9ADUPzNtOwM6-JUgdTbg_1774159859 Received: from mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com [10.30.177.12]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by mx-prod-mc-06.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 8BAD61800365; Sun, 22 Mar 2026 06:10:58 +0000 (UTC) Received: from fedora-laptop-x1.redhat.com (unknown [10.72.112.34]) by mx-prod-int-03.mail-002.prod.us-west-2.aws.redhat.com (Postfix) with ESMTPS id 223171955F2E; Sun, 22 Mar 2026 06:10:50 +0000 (UTC) From: Li Wang To: akpm@linux-foundation.org, yosry@kernel.org, yosryahmed@google.com, nphamcs@gmail.com, hannes@cmpxchg.org, mhocko@kernel.org, mkoutny@suse.com, muchun.song@linux.dev, tj@kernel.org, roman.gushchin@linux.dev, shakeel.butt@linux.dev Cc: longman@redhat.com, liwang@redhat.com, linux-kselftest@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org Subject: [PATCH v4 1/7] selftests/cgroup: skip test_zswap if zswap is globally disabled Date: Sun, 22 Mar 2026 14:10:32 +0800 Message-ID: <20260322061038.156146-2-liwang@redhat.com> In-Reply-To: <20260322061038.156146-1-liwang@redhat.com> References: <20260322061038.156146-1-liwang@redhat.com> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable X-Scanned-By: MIMEDefang 3.0 on 10.30.177.12 test_zswap currently only checks whether zswap is present by testing /sys/module/zswap. This misses the runtime global state exposed in /sys/module/zswap/parameters/enabled. When zswap is built/loaded but globally disabled, the zswap cgroup selftests run in an invalid environment and may fail spuriously. Check the runtime enabled state before running the tests: - skip if zswap is not configured, - fail if the enabled knob cannot be read, - skip if zswap is globally disabled. Also print a hint in the skip message on how to enable zswap. Signed-off-by: Li Wang Cc: Johannes Weiner Cc: Michal Hocko Cc: Michal Koutn=C3=BD Cc: Muchun Song Cc: Nhat Pham Cc: Tejun Heo Cc: Roman Gushchin Cc: Shakeel Butt Cc: Yosry Ahmed Acked-by: Yosry Ahmed Acked-by: Nhat Pham --- Notes: v4: - No changes. =20 v3: - Replace tri-state zswap_enabled() with check_zswap_enabled() for= clearer flow. - Move skip/fail decisions into the helper instead of branching in= main(). - Make read failure reporting more explicit by naming `/sys/module/zswap/parameters/enabled`. - Keep skip hint for enabling zswap: `echo 1 > /sys/module/zswap/parameters/enabled`. =20 v2: - remove enable/disable_zswap functions - skip the test if zswap is not enabled - reporting fail when zswap_enabled return -1 tools/testing/selftests/cgroup/test_zswap.c | 19 +++++++++++++++---- 1 file changed, 15 insertions(+), 4 deletions(-) diff --git a/tools/testing/selftests/cgroup/test_zswap.c b/tools/testing/se= lftests/cgroup/test_zswap.c index 64ebc3f3f203..e69d845d3592 100644 --- a/tools/testing/selftests/cgroup/test_zswap.c +++ b/tools/testing/selftests/cgroup/test_zswap.c @@ -589,9 +589,21 @@ struct zswap_test { }; #undef T =20 -static bool zswap_configured(void) +static void check_zswap_enabled(void) { - return access("/sys/module/zswap", F_OK) =3D=3D 0; + char value[2]; + + if (access("/sys/module/zswap", F_OK)) + ksft_exit_skip("zswap isn't configured\n"); + + if (read_text("/sys/module/zswap/parameters/enabled", value, + sizeof(value)) <=3D 0) + ksft_exit_fail_msg("Failed to read " + "/sys/module/zswap/parameters/enabled\n"); + + if (value[0] =3D=3D 'N') + ksft_exit_skip("zswap is disabled (hint: echo 1 > " + "/sys/module/zswap/parameters/enabled)\n"); } =20 int main(int argc, char **argv) @@ -604,8 +616,7 @@ int main(int argc, char **argv) if (cg_find_unified_root(root, sizeof(root), NULL)) ksft_exit_skip("cgroup v2 isn't mounted\n"); =20 - if (!zswap_configured()) - ksft_exit_skip("zswap isn't configured\n"); + check_zswap_enabled(); =20 /* * Check that memory controller is available: --=20 2.53.0