From patchwork Tue Dec 12 10:28:54 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: Haakon Bugge X-Patchwork-Id: 13488889 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=oracle.com header.i=@oracle.com header.b="Ric0Z6BP" Received: from mx0b-00069f02.pphosted.com (mx0b-00069f02.pphosted.com [205.220.177.32]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B5474A6 for ; Tue, 12 Dec 2023 02:29:02 -0800 (PST) Received: from pps.filterd (m0246630.ppops.net [127.0.0.1]) by mx0b-00069f02.pphosted.com (8.17.1.19/8.17.1.19) with ESMTP id 3BC7hpaG021911; Tue, 12 Dec 2023 10:29:00 GMT DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=oracle.com; h=from : to : cc : subject : date : message-id : mime-version : content-type : content-transfer-encoding; s=corp-2023-11-20; bh=jPCSxE5Uu9MRojr0nHSf40niePA/lrdFtggAznv+Ksw=; b=Ric0Z6BPDHA7BMxyYlPza2SuYuV2JQWLNG8K7Q5HICITiSPqr7Wbdl2ib5Wiu2dMZ+nH KrzZxzgtzDaNfN4RY8c9AHT2GELB3xbChQ8yysPo8SXiOdJx5Geqn3nnDHLSU0f6UTht AAjfKSGzUd+19hpmVybO1U2kAXKfVEvEdprvntLtQy/9sxW8k8yV4ez9Gw8WZP5Vg2B8 Nybyg3Pa/8bf+3JME3mD6hdC/E28Jo+hcYvCGl2Wk5bqftL804o5GMrFXuVTnzfEquIF hD2YeXGvKsbzGTHKKf0hBUjDeGmQ0mMooLc2wFV2nc0+/YgjoZiufEIX2g7TzmJI7SfJ ww== Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.appoci.oracle.com [147.154.18.20]) by mx0b-00069f02.pphosted.com (PPS) with ESMTPS id 3uwgn3kjxt-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Dec 2023 10:29:00 +0000 Received: from pps.filterd (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (8.17.1.19/8.17.1.19) with ESMTP id 3BC9A4Zu003210; Tue, 12 Dec 2023 10:28:59 GMT Received: from pps.reinject (localhost [127.0.0.1]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTPS id 3uvep6cmr8-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Tue, 12 Dec 2023 10:28:59 +0000 Received: from iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com [127.0.0.1]) by pps.reinject (8.17.1.5/8.17.1.5) with ESMTP id 3BCASxHO033207; Tue, 12 Dec 2023 10:28:59 GMT Received: from lab61.no.oracle.com (lab61.no.oracle.com [10.172.144.82]) by iadpaimrmta02.imrmtpd1.prodappiadaev1.oraclevcn.com (PPS) with ESMTP id 3uvep6cmqk-1; Tue, 12 Dec 2023 10:28:59 +0000 From: =?utf-8?q?H=C3=A5kon_Bugge?= To: Paul Moore , Eric Paris , audit@vger.kernel.org Cc: Ankur Arora Subject: [PATCH 0/2] audit: Further reduce syscall latency Date: Tue, 12 Dec 2023 11:28:54 +0100 Message-Id: <20231212102857.803984-1-haakon.bugge@oracle.com> X-Mailer: git-send-email 2.39.3 Precedence: bulk X-Mailing-List: audit@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=baseguard engine=ICAP:2.0.272,Aquarius:18.0.997,Hydra:6.0.619,FMLib:17.11.176.26 definitions=2023-12-12_04,2023-12-12_01,2023-05-22_02 X-Proofpoint-Spam-Details: rule=notspam policy=default score=0 phishscore=0 bulkscore=0 spamscore=0 malwarescore=0 mlxscore=0 mlxlogscore=787 adultscore=0 suspectscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2311290000 definitions=main-2312120083 X-Proofpoint-ORIG-GUID: CKXmaDOK0uZ-1o4Hh2HUu23fFc2hUnUS X-Proofpoint-GUID: CKXmaDOK0uZ-1o4Hh2HUu23fFc2hUnUS On an Intel Cascade Lake, booted with "audit=0" and "mitigations=off", syscall latency in nanoseconds over 10 reboots and 5 runs is: getpid() latency: Boot parameters kernel min avg max pstdev (ns) (ns) (ns) (ns) audit=0, mitigations=off v6.6-rc4 55 55 58 0.797245 audit=1, mitigations=off v6.6-rc4 205 210 227 6.402000 audit=1, mitigations=off v6.6-rc4+[1] 203 203 209 0.954149 audit=1, mitigations=off v6.6-rc4+[1]+[2] 173 173 178 0.884534 So, audit contributes significantly to the cost of a system call. This series, hopefully applicable to audit/next (if accepted), reduces the syscall latency by a decent 21% on an Intel Cascade Lake system. The above numbers are derived using the same methodology as mentioned in the commit messages. The first commit, "audit: Vary struct audit_entry alignment", fixes a huge L1D miss ratio and greatly reduces the variability on the three metrics, nanoseconds per syscall, L1D misses per syscall, and Instructions per Cycle (ipc). It does not greatly reduce on the syscall latency, only a decent 3.5% reduction. But, it serves as a pre-requisite for the second commit, "audit: Apply codegen optimizations". Please review. Håkon Bugge (2): [1] audit: Vary struct audit_entry alignment [2] audit: Apply codegen optimizations kernel/auditfilter.c | 14 +++++++++++--- kernel/auditsc.c | 2 ++ 2 files changed, 13 insertions(+), 3 deletions(-) --- 2.39.3