From patchwork Mon Jul 25 05:11:21 2016 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jisheng Zhang X-Patchwork-Id: 9245243 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 97162607D3 for ; Mon, 25 Jul 2016 05:17:55 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 87A9725250 for ; Mon, 25 Jul 2016 05:17:55 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 7BF5E26224; Mon, 25 Jul 2016 05:17:55 +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 1492525250 for ; Mon, 25 Jul 2016 05:17:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752285AbcGYFRx (ORCPT ); Mon, 25 Jul 2016 01:17:53 -0400 Received: from mx0b-0016f401.pphosted.com ([67.231.156.173]:12499 "EHLO mx0b-0016f401.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752271AbcGYFRx (ORCPT ); Mon, 25 Jul 2016 01:17:53 -0400 Received: from pps.filterd (m0045851.ppops.net [127.0.0.1]) by mx0b-0016f401.pphosted.com (8.16.0.17/8.16.0.17) with SMTP id u6P5EaXI000773; Sun, 24 Jul 2016 22:17:22 -0700 Received: from sc-exch02.marvell.com ([199.233.58.182]) by mx0b-0016f401.pphosted.com with ESMTP id 24c83gwgcn-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-SHA384 bits=256 verify=NOT); Sun, 24 Jul 2016 22:17:22 -0700 Received: from SC-EXCH04.marvell.com (10.93.176.84) by SC-EXCH02.marvell.com (10.93.176.82) with Microsoft SMTP Server (TLS) id 15.0.1104.5; Sun, 24 Jul 2016 22:17:20 -0700 Received: from maili.marvell.com (10.93.176.43) by SC-EXCH04.marvell.com (10.93.176.84) with Microsoft SMTP Server id 15.0.1104.5 via Frontend Transport; Sun, 24 Jul 2016 22:17:20 -0700 Received: from xhacker.marvell.com (unknown [10.37.130.123]) by maili.marvell.com (Postfix) with ESMTP id E85083F703F; Sun, 24 Jul 2016 22:17:18 -0700 (PDT) From: Jisheng Zhang To: , , , , CC: , , , Jisheng Zhang Subject: [PATCH v2] PM / OPP: optimize dev_pm_opp_set_rate() performance a bit Date: Mon, 25 Jul 2016 13:11:21 +0800 Message-ID: <1469423481-1621-1-git-send-email-jszhang@marvell.com> X-Mailer: git-send-email 2.8.1 MIME-Version: 1.0 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:, , definitions=2016-07-25_03:, , signatures=0 X-Proofpoint-Details: rule=outbound_notspam policy=outbound score=0 spamscore=0 suspectscore=0 malwarescore=0 phishscore=0 adultscore=0 bulkscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.0.1-1604210000 definitions=main-1607250068 Sender: linux-pm-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pm@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP In dev_pm_opp_set_rate(), _find_opp_table() is called 4 times: once by _get_opp_clk(), once by dev_pm_opp_set_rate() itself, and twice by dev_pm_opp_find_freq_ceil(). If there are several opp_tables in the system, three times of opp table finding is a big waste. This patch reduced the call of _find_opp_table() to twice. Signed-off-by: Jisheng Zhang --- Since v1: - avoid opp_table pointer usage after the rcu_read_unlock() as pointed out by Viresh, thus we can only reduced the call of _find_opp_table to twice. drivers/base/power/opp/core.c | 31 +++++++++++++++++++------------ 1 file changed, 19 insertions(+), 12 deletions(-) diff --git a/drivers/base/power/opp/core.c b/drivers/base/power/opp/core.c index 7c04c87..cde7514 100644 --- a/drivers/base/power/opp/core.c +++ b/drivers/base/power/opp/core.c @@ -402,6 +402,22 @@ struct dev_pm_opp *dev_pm_opp_find_freq_exact(struct device *dev, } EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_exact); +static struct dev_pm_opp *_find_freq_ceil(struct opp_table *opp_table, + unsigned long *freq) +{ + struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE); + + list_for_each_entry_rcu(temp_opp, &opp_table->opp_list, node) { + if (temp_opp->available && temp_opp->rate >= *freq) { + opp = temp_opp; + *freq = opp->rate; + break; + } + } + + return opp; +} + /** * dev_pm_opp_find_freq_ceil() - Search for an rounded ceil freq * @dev: device for which we do this operation @@ -427,7 +443,6 @@ struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev, unsigned long *freq) { struct opp_table *opp_table; - struct dev_pm_opp *temp_opp, *opp = ERR_PTR(-ERANGE); opp_rcu_lockdep_assert(); @@ -440,15 +455,7 @@ struct dev_pm_opp *dev_pm_opp_find_freq_ceil(struct device *dev, if (IS_ERR(opp_table)) return ERR_CAST(opp_table); - list_for_each_entry_rcu(temp_opp, &opp_table->opp_list, node) { - if (temp_opp->available && temp_opp->rate >= *freq) { - opp = temp_opp; - *freq = opp->rate; - break; - } - } - - return opp; + return _find_freq_ceil(opp_table, freq); } EXPORT_SYMBOL_GPL(dev_pm_opp_find_freq_ceil); @@ -612,7 +619,7 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq) return PTR_ERR(opp_table); } - old_opp = dev_pm_opp_find_freq_ceil(dev, &old_freq); + old_opp = _find_freq_ceil(opp_table, &old_freq); if (!IS_ERR(old_opp)) { ou_volt = old_opp->u_volt; ou_volt_min = old_opp->u_volt_min; @@ -622,7 +629,7 @@ int dev_pm_opp_set_rate(struct device *dev, unsigned long target_freq) __func__, old_freq, PTR_ERR(old_opp)); } - opp = dev_pm_opp_find_freq_ceil(dev, &freq); + opp = _find_freq_ceil(opp_table, &freq); if (IS_ERR(opp)) { ret = PTR_ERR(opp); dev_err(dev, "%s: failed to find OPP for freq %lu (%d)\n",