From nobody Sun May 24 19:33:15 2026 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.19]) (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 AC596383C9E; Sat, 23 May 2026 10:26:26 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.19 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779531990; cv=none; b=dj/dkTwiRT6/sxyKIjxwEUKVASnYBEuTFdVA5g1Ntz9UEkz/TvxMzAAKSIG7TBc2pHzw96OduM79EsgY/M/kFuccZH9bwiYk4BdY8vl5fCkHMQEMJ83N1i47A2ojMrVh4VfK66KjdSBKn7Y87yZVLAOuQ1qsFzarCzjQOkAirKA= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1779531990; c=relaxed/simple; bh=BzHefG7rr33yy6nquqfF6P+UyfN2CHmgpf9L5I7QVGI=; h=From:To:Cc:Subject:Date:Message-Id:MIME-Version; b=d4n5WFGrFEvJkk4g15deuldo5wDlid/IX8Qd7CgTGuUaQPZEfqOObFDynjI19frsc/IlsEYXKQVCeTrHmOCPTA1yu/DUdx5z8gCa/sKBB/IjU1QjY5ZYFNzSYTAuUmjD8xdSXRjobqD4G5b0M+43JBA2BvKH9lPfKqFXVWvOFsc= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=Wvwp6GW9; arc=none smtp.client-ip=198.175.65.19 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="Wvwp6GW9" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1779531986; x=1811067986; h=from:to:cc:subject:date:message-id:mime-version: content-transfer-encoding; bh=BzHefG7rr33yy6nquqfF6P+UyfN2CHmgpf9L5I7QVGI=; b=Wvwp6GW9zhQcMI8suJDspn9i9tFzT1t3Ji9kSNvVPjm+oHL0pmKIeNd7 sk8gNkiB0x2Qi2x6OU2mYpqJTcpwksFDBwqYLyPp8kFdwRXUHVVzHajln S4pV9mCGsj/zU+NSoqzbYUNEyoxqgj0hVhFctQQkU1xqa7MQR8/FnF6Ix NynGCci6SAZ/R+mlxE1Y9r443FowGZ9104QwvXKab1xLvrNMRWkq+yfyW NXweiBzFEeN+MvrPRhHS7JYcxvdVuxiapyo91IpdepjWOuhFOODdiNb/d l4WuYwv3310XQpteSzxgj/TELDnCRHx5gCXJClbOpvUGp4y06BbIrwPCT Q==; X-CSE-ConnectionGUID: wWR+IwEDT4SVWygqIzK1Qw== X-CSE-MsgGUID: pr8QRdjaRZ+N7voxRix4gw== X-IronPort-AV: E=McAfee;i="6800,10657,11794"; a="80410331" X-IronPort-AV: E=Sophos;i="6.24,164,1774335600"; d="scan'208";a="80410331" Received: from orviesa004.jf.intel.com ([10.64.159.144]) by orvoesa111.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 23 May 2026 03:26:26 -0700 X-CSE-ConnectionGUID: +1cy6XeURPGdMViGu+nzLA== X-CSE-MsgGUID: bUwKubthQzyoNmRpJ1mysA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.24,164,1774335600"; d="scan'208";a="245425647" Received: from chenyu-dev.sh.intel.com ([10.239.62.107]) by orviesa004.jf.intel.com with ESMTP; 23 May 2026 03:26:24 -0700 From: Chen Yu To: Tony Luck , Reinette Chatre Cc: x86@kernel.org, Dave Martin , James Morse , Babu Moger , linux-kernel@vger.kernel.org, linux-kselftest@vger.kernel.org, Chen Yu , Hongyu Ning Subject: [PATCH] selftests/resctrl: Allow CAT testing when no exclusive cache exists Date: Sat, 23 May 2026 18:17:15 +0800 Message-Id: <20260523101715.3964456-1-yu.c.chen@intel.com> X-Mailer: git-send-email 2.25.1 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="utf-8" The shareable_bits indicates which cache portions might be shared with other agents (e.g., GPU, other I/O devices). On some platforms, all L3 cache ways are marked as potentially shared. The L3_CAT test should fall back to using the full CBM mask when no exclusive portion exists, since the test logic (writing different schemata and measuring cache misses) still works. The shareable mask is a hint about potential interference, not a hard exclusion. Reported-by: Hongyu Ning Signed-off-by: Chen Yu --- tools/testing/selftests/resctrl/cat_test.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/tools/testing/selftests/resctrl/cat_test.c b/tools/testing/sel= ftests/resctrl/cat_test.c index f00b622c1460..b6994ba4504b 100644 --- a/tools/testing/selftests/resctrl/cat_test.c +++ b/tools/testing/selftests/resctrl/cat_test.c @@ -248,7 +248,7 @@ static int cat_run_test(const struct resctrl_test *test= , const struct user_param /* Get the largest contiguous exclusive portion of the cache */ ret =3D get_mask_no_shareable(test->resource, &long_mask); if (ret) - return ret; + long_mask =3D full_cache_mask; =20 /* Get L3/L2 cache size */ ret =3D get_cache_size(uparams->cpu, test->resource, &cache_total_size); --=20 2.25.1