From patchwork Wed Feb 28 19:18:28 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Nayna X-Patchwork-Id: 10249379 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 6998E60211 for ; Wed, 28 Feb 2018 19:19:04 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 52E1928DB1 for ; Wed, 28 Feb 2018 19:19:04 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 4701028DF9; Wed, 28 Feb 2018 19:19:04 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id E0A8528DB1 for ; Wed, 28 Feb 2018 19:19:03 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933586AbeB1TTB (ORCPT ); Wed, 28 Feb 2018 14:19:01 -0500 Received: from mx0b-001b2d01.pphosted.com ([148.163.158.5]:55468 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932780AbeB1TS7 (ORCPT ); Wed, 28 Feb 2018 14:18:59 -0500 Received: from pps.filterd (m0098414.ppops.net [127.0.0.1]) by mx0b-001b2d01.pphosted.com (8.16.0.22/8.16.0.22) with SMTP id w1SJExgB011031 for ; Wed, 28 Feb 2018 14:18:59 -0500 Received: from e06smtp14.uk.ibm.com (e06smtp14.uk.ibm.com [195.75.94.110]) by mx0b-001b2d01.pphosted.com with ESMTP id 2gdyjq094h-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 28 Feb 2018 14:18:58 -0500 Received: from localhost by e06smtp14.uk.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! 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Violators will be prosecuted; Wed, 28 Feb 2018 19:18:55 -0000 Received: from d06av25.portsmouth.uk.ibm.com (d06av25.portsmouth.uk.ibm.com [9.149.105.61]) by b06cxnps4074.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id w1SJItu046006360; Wed, 28 Feb 2018 19:18:55 GMT Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id D366211C04C; Wed, 28 Feb 2018 19:11:47 +0000 (GMT) Received: from d06av25.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id AF00A11C058; Wed, 28 Feb 2018 19:11:46 +0000 (GMT) Received: from localhost.endicott.ibm.com (unknown [9.60.15.245]) by d06av25.portsmouth.uk.ibm.com (Postfix) with ESMTP; Wed, 28 Feb 2018 19:11:46 +0000 (GMT) From: Nayna Jain To: linux-integrity@vger.kernel.org Cc: zohar@linux.vnet.ibm.com, linux-security-module@vger.kernel.org, linux-kernel@vger.kernel.org, peterhuewe@gmx.de, jarkko.sakkinen@linux.intel.com, tpmdd@selhorst.net, jgunthorpe@obsidianresearch.com, patrickc@us.ibm.com, Nayna Jain Subject: [RFC PATCH 3/3] tpm: tpm_msleep() with finer granularity improves performance Date: Wed, 28 Feb 2018 14:18:28 -0500 X-Mailer: git-send-email 2.13.3 In-Reply-To: <20180228191828.20056-1-nayna@linux.vnet.ibm.com> References: <20180228191828.20056-1-nayna@linux.vnet.ibm.com> X-TM-AS-GCONF: 00 x-cbid: 18022819-0016-0000-0000-0000052B1E78 X-IBM-AV-DETECTION: SAVI=unused REMOTE=unused XFE=unused x-cbparentid: 18022819-0017-0000-0000-000028681FA3 Message-Id: <20180228191828.20056-3-nayna@linux.vnet.ibm.com> X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2018-02-28_11:, , signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 priorityscore=1501 malwarescore=0 suspectscore=1 phishscore=0 bulkscore=0 spamscore=0 clxscore=1015 lowpriorityscore=0 impostorscore=0 adultscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1709140000 definitions=main-1802280234 Sender: owner-linux-security-module@vger.kernel.org Precedence: bulk List-ID: X-Virus-Scanned: ClamAV using ClamSMTP When 'commit 9f3fc7bcddcb ("tpm: replace msleep() with usleep_range() in TPM 1.2/2.0 generic drivers")' was upstreamed, it replaced the msleep() calls with usleep_range(), but did not change the granularity of the calls. They're still defined in terms of msec. Test results show that refining the granularity further improves the performance. We're posting this patch as an RFC to show that there needs to be another function which allows finer granularity. After this change, performance on a TPM 1.2 with an 8 byte burstcount for 1000 extends improved from ~10.7sec to ~6.9sec. Signed-off-by: Nayna Jain --- drivers/char/tpm/tpm.h | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) diff --git a/drivers/char/tpm/tpm.h b/drivers/char/tpm/tpm.h index 7e797377e1eb..8cad6bfc5f46 100644 --- a/drivers/char/tpm/tpm.h +++ b/drivers/char/tpm/tpm.h @@ -522,8 +522,7 @@ int tpm_pm_resume(struct device *dev); static inline void tpm_msleep(unsigned int delay_msec) { - usleep_range((delay_msec * 1000) - TPM_TIMEOUT_RANGE_US, - delay_msec * 1000); + usleep_range((delay_msec * 1000) / 10, (delay_msec * 1000) / 2); }; struct tpm_chip *tpm_chip_find_get(struct tpm_chip *chip);